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samba-mirror/python/samba/kcc/__init__.py
Douglas Bagnall 7cd35051c8 KCC: split and shift samba.graph_utils -> samba.kcc.{graph_utils,debug} 
The debug module contains debug functions and colours.

Graph_utils keeps the DOT file generation and graph verification code.

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
2015-06-12 06:57:13 +02:00

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# define the KCC object
#
# Copyright (C) Dave Craft 2011
# Copyright (C) Andrew Bartlett 2015
#
# Andrew Bartlett's alleged work performed by his underlings Douglas
# Bagnall and Garming Sam.
#
# 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 <http://www.gnu.org/licenses/>.
import os
import sys
import random
import uuid
# ensure we get messages out immediately, so they get in the samba logs,
# and don't get swallowed by a timeout
os.environ['PYTHONUNBUFFERED'] = '1'
# forcing GMT avoids a problem in some timezones with kerberos. Both MIT
# heimdal can get mutual authentication errors due to the 24 second difference
# between UTC and GMT when using some zone files (eg. the PDT zone from
# the US)
os.environ["TZ"] = "GMT"
# Find right directory when running from source tree
sys.path.insert(0, "bin/python")
import optparse
import logging
import itertools
import heapq
import time
from functools import partial
from samba import (
getopt as options,
ldb,
dsdb,
drs_utils,
nttime2unix)
from samba.auth import system_session
from samba.samdb import SamDB
from samba.dcerpc import drsuapi
from samba.kcc_utils import *
from samba.kcc.graph_utils import verify_and_dot
from samba import ldif_utils
from samba.kcc.debug import DEBUG, DEBUG_FN, logger
from samba.kcc import debug
class KCC(object):
"""The Knowledge Consistency Checker class.
A container for objects and methods allowing a run of the KCC. Produces a
set of connections in the samdb for which the Distributed Replication
Service can then utilize to replicate naming contexts
:param unix_now: The putative current time in seconds since 1970.
:param read_only: Don't write to the database.
:param verify: Check topological invariants for the generated graphs
:param debug: Write verbosely to stderr.
"param dot_files: write Graphviz files in /tmp showing topology
"""
def __init__(self, unix_now, readonly=False, attempt_live_connections=True,
verify=False, debug=False, dot_files=False):
"""Initializes the partitions class which can hold
our local DCs partitions or all the partitions in
the forest
"""
self.part_table = {} # partition objects
self.site_table = {}
self.transport_table = {}
self.ip_transport = None
self.sitelink_table = {}
self.dsa_by_dnstr = {}
self.dsa_by_guid = {}
self.get_dsa_by_guidstr = self.dsa_by_guid.get
self.get_dsa = self.dsa_by_dnstr.get
# TODO: These should be backed by a 'permanent' store so that when
# calling DRSGetReplInfo with DS_REPL_INFO_KCC_DSA_CONNECT_FAILURES,
# the failure information can be returned
self.kcc_failed_links = {}
self.kcc_failed_connections = set()
# Used in inter-site topology computation. A list
# of connections (by NTDSConnection object) that are
# to be kept when pruning un-needed NTDS Connections
self.kept_connections = set()
self.my_dsa_dnstr = None # My dsa DN
self.my_dsa = None # My dsa object
self.my_site_dnstr = None
self.my_site = None
self.samdb = None
self.unix_now = unix_now
self.nt_now = unix2nttime(unix_now)
self.readonly = readonly
self.attempt_live_connections = attempt_live_connections
self.verify = verify
self.debug = debug
self.dot_files = dot_files
def load_all_transports(self):
"""Loads the inter-site transport objects for Sites
:return: None
:raise KCCError: if no IP transport is found
"""
try:
res = self.samdb.search("CN=Inter-Site Transports,CN=Sites,%s" %
self.samdb.get_config_basedn(),
scope=ldb.SCOPE_SUBTREE,
expression="(objectClass=interSiteTransport)")
except ldb.LdbError, (enum, estr):
raise KCCError("Unable to find inter-site transports - (%s)" %
estr)
for msg in res:
dnstr = str(msg.dn)
transport = Transport(dnstr)
transport.load_transport(self.samdb)
self.transport_table.setdefault(str(transport.guid),
transport)
if transport.name == 'IP':
self.ip_transport = transport
if self.ip_transport is None:
raise KCCError("there doesn't seem to be an IP transport")
def load_all_sitelinks(self):
"""Loads the inter-site siteLink objects
:return: None
:raise KCCError: if site-links aren't found
"""
try:
res = self.samdb.search("CN=Inter-Site Transports,CN=Sites,%s" %
self.samdb.get_config_basedn(),
scope=ldb.SCOPE_SUBTREE,
expression="(objectClass=siteLink)")
except ldb.LdbError, (enum, estr):
raise KCCError("Unable to find inter-site siteLinks - (%s)" % estr)
for msg in res:
dnstr = str(msg.dn)
# already loaded
if dnstr in self.sitelink_table:
continue
sitelink = SiteLink(dnstr)
sitelink.load_sitelink(self.samdb)
# Assign this siteLink to table
# and index by dn
self.sitelink_table[dnstr] = sitelink
def load_site(self, dn_str):
"""Helper for load_my_site and load_all_sites.
Put all the site's DSAs into the KCC indices.
:param dn_str: a site dn_str
:return: the Site object pertaining to the dn_str
"""
site = Site(dn_str, self.unix_now)
site.load_site(self.samdb)
# We avoid replacing the site with an identical copy in case
# somewhere else has a reference to the old one, which would
# lead to all manner of confusion and chaos.
guid = str(site.site_guid)
if guid not in self.site_table:
self.site_table[guid] = site
self.dsa_by_dnstr.update(site.dsa_table)
self.dsa_by_guid.update((str(x.dsa_guid), x)
for x in site.dsa_table.values())
return self.site_table[guid]
def load_my_site(self):
"""Load the Site object for the local DSA.
:return: None
"""
self.my_site_dnstr = ("CN=%s,CN=Sites,%s" % (
self.samdb.server_site_name(),
self.samdb.get_config_basedn()))
self.my_site = self.load_site(self.my_site_dnstr)
def load_all_sites(self):
"""Discover all sites and create Site objects.
:return: None
:raise: KCCError if sites can't be found
"""
try:
res = self.samdb.search("CN=Sites,%s" %
self.samdb.get_config_basedn(),
scope=ldb.SCOPE_SUBTREE,
expression="(objectClass=site)")
except ldb.LdbError, (enum, estr):
raise KCCError("Unable to find sites - (%s)" % estr)
for msg in res:
sitestr = str(msg.dn)
self.load_site(sitestr)
def load_my_dsa(self):
"""Discover my nTDSDSA dn thru the rootDSE entry
:return: None
:raise: KCCError if DSA can't be found
"""
dn = ldb.Dn(self.samdb, "<GUID=%s>" % self.samdb.get_ntds_GUID())
try:
res = self.samdb.search(base=dn, scope=ldb.SCOPE_BASE,
attrs=["objectGUID"])
except ldb.LdbError, (enum, estr):
logger.warning("Search for %s failed: %s. This typically happens"
" in --importldif mode due to lack of module"
" support.", dn, estr)
try:
# We work around the failure above by looking at the
# dsServiceName that was put in the fake rootdse by
# the --exportldif, rather than the
# samdb.get_ntds_GUID(). The disadvantage is that this
# mode requires we modify the @ROOTDSE dnq to support
# --forced-local-dsa
service_name_res = self.samdb.search(base="",
scope=ldb.SCOPE_BASE,
attrs=["dsServiceName"])
dn = ldb.Dn(self.samdb,
service_name_res[0]["dsServiceName"][0])
res = self.samdb.search(base=dn, scope=ldb.SCOPE_BASE,
attrs=["objectGUID"])
except ldb.LdbError, (enum, estr):
raise KCCError("Unable to find my nTDSDSA - (%s)" % estr)
if len(res) != 1:
raise KCCError("Unable to find my nTDSDSA at %s" %
dn.extended_str())
ntds_guid = misc.GUID(self.samdb.get_ntds_GUID())
if misc.GUID(res[0]["objectGUID"][0]) != ntds_guid:
raise KCCError("Did not find the GUID we expected,"
" perhaps due to --importldif")
self.my_dsa_dnstr = str(res[0].dn)
self.my_dsa = self.my_site.get_dsa(self.my_dsa_dnstr)
if self.my_dsa_dnstr not in self.dsa_by_dnstr:
debug.DEBUG_DARK_YELLOW("my_dsa %s isn't in self.dsas_by_dnstr:"
" it must be RODC.\n"
"Let's add it, because my_dsa is special!"
"\n(likewise for self.dsa_by_guid)" %
self.my_dsas_dnstr)
self.dsa_by_dnstr[self.my_dsa_dnstr] = self.my_dsa
self.dsa_by_guid[str(self.my_dsa.dsa_guid)] = self.my_dsa
def load_all_partitions(self):
"""Discover and load all partitions.
Each NC is inserted into the part_table by partition
dn string (not the nCName dn string)
:return: None
:raise: KCCError if partitions can't be found
"""
try:
res = self.samdb.search("CN=Partitions,%s" %
self.samdb.get_config_basedn(),
scope=ldb.SCOPE_SUBTREE,
expression="(objectClass=crossRef)")
except ldb.LdbError, (enum, estr):
raise KCCError("Unable to find partitions - (%s)" % estr)
for msg in res:
partstr = str(msg.dn)
# already loaded
if partstr in self.part_table:
continue
part = Partition(partstr)
part.load_partition(self.samdb)
self.part_table[partstr] = part
def should_be_present_test(self):
"""Enumerate all loaded partitions and DSAs in local
site and test if NC should be present as replica
"""
for partdn, part in self.part_table.items():
for dsadn, dsa in self.my_site.dsa_table.items():
needed, ro, partial = part.should_be_present(dsa)
logger.info("dsadn:%s\nncdn:%s\nneeded=%s:ro=%s:partial=%s\n" %
(dsadn, part.nc_dnstr, needed, ro, partial))
def refresh_failed_links_connections(self):
"""Based on MS-ADTS 6.2.2.1"""
# Instead of NULL link with failure_count = 0, the tuple is
# simply removed
# LINKS: Refresh failed links
self.kcc_failed_links = {}
current, needed = self.my_dsa.get_rep_tables()
for replica in current.values():
# For every possible connection to replicate
for reps_from in replica.rep_repsFrom:
failure_count = reps_from.consecutive_sync_failures
if failure_count <= 0:
continue
dsa_guid = str(reps_from.source_dsa_obj_guid)
time_first_failure = reps_from.last_success
last_result = reps_from.last_attempt
dns_name = reps_from.dns_name1
f = self.kcc_failed_links.get(dsa_guid)
if not f:
f = KCCFailedObject(dsa_guid, failure_count,
time_first_failure, last_result,
dns_name)
self.kcc_failed_links[dsa_guid] = f
#elif f.failure_count == 0:
# f.failure_count = failure_count
# f.time_first_failure = time_first_failure
# f.last_result = last_result
else:
f.failure_count = max(f.failure_count, failure_count)
f.time_first_failure = min(f.time_first_failure,
time_first_failure)
f.last_result = last_result
# CONNECTIONS: Refresh failed connections
restore_connections = set()
if self.attempt_live_connections:
DEBUG("refresh_failed_links: checking if links are still down")
for connection in self.kcc_failed_connections:
try:
drs_utils.drsuapi_connect(connection.dns_name, lp, creds)
# Failed connection is no longer failing
restore_connections.add(connection)
except drs_utils.drsException:
# Failed connection still failing
connection.failure_count += 1
else:
DEBUG("refresh_failed_links: not checking live links because we\n"
"weren't asked to --attempt-live-connections")
# Remove the restored connections from the failed connections
self.kcc_failed_connections.difference_update(restore_connections)
def is_stale_link_connection(self, target_dsa):
"""Check whether a link to a remote DSA is stale
Used in MS-ADTS 6.2.2.2 Intrasite Connection Creation
Returns True if the remote seems to have been down for at
least two hours, otherwise False.
:param target_dsa: the remote DSA object
:return: True if link is stale, otherwise False
"""
failed_link = self.kcc_failed_links.get(str(target_dsa.dsa_guid))
if failed_link:
# failure_count should be > 0, but check anyways
if failed_link.failure_count > 0:
unix_first_failure = \
nttime2unix(failed_link.time_first_failure)
# TODO guard against future
if unix_first_failure > self.unix_now:
logger.error("The last success time attribute for \
repsFrom is in the future!")
# Perform calculation in seconds
if (self.unix_now - unix_first_failure) > 60 * 60 * 2:
return True
# TODO connections
return False
# TODO: This should be backed by some form of local database
def remove_unneeded_failed_links_connections(self):
# Remove all tuples in kcc_failed_links where failure count = 0
# In this implementation, this should never happen.
# Remove all connections which were not used this run or connections
# that became active during this run.
pass
def remove_unneeded_ntdsconn(self, all_connected):
"""Remove unneeded NTDS Connections once topology is calculated
Based on MS-ADTS 6.2.2.4 Removing Unnecessary Connections
:param all_connected: indicates whether all sites are connected
:return: None
"""
mydsa = self.my_dsa
# New connections won't have GUIDs which are needed for
# sorting. Add them.
for cn_conn in mydsa.connect_table.values():
if cn_conn.guid is None:
if self.readonly:
cn_conn.guid = misc.GUID(str(uuid.uuid4()))
cn_conn.whenCreated = self.nt_now
else:
cn_conn.load_connection(self.samdb)
for cn_conn in mydsa.connect_table.values():
s_dnstr = cn_conn.get_from_dnstr()
if s_dnstr is None:
cn_conn.to_be_deleted = True
continue
# Get the source DSA no matter what site
# XXX s_dsa is NEVER USED. It will be removed.
s_dsa = self.get_dsa(s_dnstr)
#XXX should an RODC be regarded as same site
same_site = s_dnstr in self.my_site.dsa_table
# Given an nTDSConnection object cn, if the DC with the
# nTDSDSA object dc that is the parent object of cn and
# the DC with the nTDSDA object referenced by cn!fromServer
# are in the same site, the KCC on dc deletes cn if all of
# the following are true:
#
# Bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options.
#
# No site settings object s exists for the local DC's site, or
# bit NTDSSETTINGS_OPT_IS_TOPL_CLEANUP_DISABLED is clear in
# s!options.
#
# Another nTDSConnection object cn2 exists such that cn and
# cn2 have the same parent object, cn!fromServer = cn2!fromServer,
# and either
#
# cn!whenCreated < cn2!whenCreated
#
# cn!whenCreated = cn2!whenCreated and
# cn!objectGUID < cn2!objectGUID
#
# Bit NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options
if same_site:
if not cn_conn.is_generated():
continue
if self.my_site.is_cleanup_ntdsconn_disabled():
continue
# Loop thru connections looking for a duplicate that
# fulfills the previous criteria
lesser = False
packed_guid = ndr_pack(cn_conn.guid)
for cn2_conn in mydsa.connect_table.values():
if cn2_conn is cn_conn:
continue
s2_dnstr = cn2_conn.get_from_dnstr()
# If the NTDS Connections has a different
# fromServer field then no match
if s2_dnstr != s_dnstr:
continue
#XXX GUID comparison
lesser = (cn_conn.whenCreated < cn2_conn.whenCreated or
(cn_conn.whenCreated == cn2_conn.whenCreated and
packed_guid < ndr_pack(cn2_conn.guid)))
if lesser:
break
if lesser and not cn_conn.is_rodc_topology():
cn_conn.to_be_deleted = True
# Given an nTDSConnection object cn, if the DC with the nTDSDSA
# object dc that is the parent object of cn and the DC with
# the nTDSDSA object referenced by cn!fromServer are in
# different sites, a KCC acting as an ISTG in dc's site
# deletes cn if all of the following are true:
#
# Bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options.
#
# cn!fromServer references an nTDSDSA object for a DC
# in a site other than the local DC's site.
#
# The keepConnections sequence returned by
# CreateIntersiteConnections() does not contain
# cn!objectGUID, or cn is "superseded by" (see below)
# another nTDSConnection cn2 and keepConnections
# contains cn2!objectGUID.
#
# The return value of CreateIntersiteConnections()
# was true.
#
# Bit NTDSCONN_OPT_RODC_TOPOLOGY is clear in
# cn!options
#
else: # different site
if not mydsa.is_istg():
continue
if not cn_conn.is_generated():
continue
# TODO
# We are directly using this connection in intersite or
# we are using a connection which can supersede this one.
#
# MS-ADTS 6.2.2.4 - Removing Unnecessary Connections does not
# appear to be correct.
#
# 1. cn!fromServer and cn!parent appear inconsistent with
# no cn2
# 2. The repsFrom do not imply each other
#
if cn_conn in self.kept_connections: # and not_superceded:
continue
# This is the result of create_intersite_connections
if not all_connected:
continue
if not cn_conn.is_rodc_topology():
cn_conn.to_be_deleted = True
if mydsa.is_ro() or self.readonly:
for connect in mydsa.connect_table.values():
if connect.to_be_deleted:
DEBUG_FN("TO BE DELETED:\n%s" % connect)
if connect.to_be_added:
DEBUG_FN("TO BE ADDED:\n%s" % connect)
# Peform deletion from our tables but perform
# no database modification
mydsa.commit_connections(self.samdb, ro=True)
else:
# Commit any modified connections
mydsa.commit_connections(self.samdb)
def modify_repsFrom(self, n_rep, t_repsFrom, s_rep, s_dsa, cn_conn):
"""Update an repsFrom object if required.
Part of MS-ADTS 6.2.2.5.
Update t_repsFrom if necessary to satisfy requirements. Such
updates are typically required when the IDL_DRSGetNCChanges
server has moved from one site to another--for example, to
enable compression when the server is moved from the
client's site to another site.
The repsFrom.update_flags bit field may be modified
auto-magically if any changes are made here. See
kcc_utils.RepsFromTo for gory details.
:param n_rep: NC replica we need
:param t_repsFrom: repsFrom tuple to modify
:param s_rep: NC replica at source DSA
:param s_dsa: source DSA
:param cn_conn: Local DSA NTDSConnection child
:return: None
"""
s_dnstr = s_dsa.dsa_dnstr
update = 0x0
same_site = s_dnstr in self.my_site.dsa_table
# if schedule doesn't match then update and modify
times = convert_schedule_to_repltimes(cn_conn.schedule)
if times != t_repsFrom.schedule:
t_repsFrom.schedule = times
update |= drsuapi.DRSUAPI_DRS_UPDATE_SCHEDULE
# Bit DRS_PER_SYNC is set in replicaFlags if and only
# if nTDSConnection schedule has a value v that specifies
# scheduled replication is to be performed at least once
# per week.
if cn_conn.is_schedule_minimum_once_per_week():
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_PER_SYNC) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_PER_SYNC
# Bit DRS_INIT_SYNC is set in t.replicaFlags if and only
# if the source DSA and the local DC's nTDSDSA object are
# in the same site or source dsa is the FSMO role owner
# of one or more FSMO roles in the NC replica.
if same_site or n_rep.is_fsmo_role_owner(s_dnstr):
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_INIT_SYNC) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_INIT_SYNC
# If bit NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT is set in
# cn!options, bit DRS_NEVER_NOTIFY is set in t.replicaFlags
# if and only if bit NTDSCONN_OPT_USE_NOTIFY is clear in
# cn!options. Otherwise, bit DRS_NEVER_NOTIFY is set in
# t.replicaFlags if and only if s and the local DC's
# nTDSDSA object are in different sites.
if ((cn_conn.options &
dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT) != 0x0):
if (cn_conn.options & dsdb.NTDSCONN_OPT_USE_NOTIFY) == 0x0:
# XXX WARNING
#
# it LOOKS as if this next test is a bit silly: it
# checks the flag then sets it if it not set; the same
# effect could be achieved by unconditionally setting
# it. But in fact the repsFrom object has special
# magic attached to it, and altering replica_flags has
# side-effects. That is bad in my opinion, but there
# you go.
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_NEVER_NOTIFY) == 0x0):
t_repsFrom.replica_flags |= \
drsuapi.DRSUAPI_DRS_NEVER_NOTIFY
elif not same_site:
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_NEVER_NOTIFY) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_NEVER_NOTIFY
# Bit DRS_USE_COMPRESSION is set in t.replicaFlags if
# and only if s and the local DC's nTDSDSA object are
# not in the same site and the
# NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION bit is
# clear in cn!options
if (not same_site and
(cn_conn.options &
dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION) == 0x0):
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_USE_COMPRESSION) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_USE_COMPRESSION
# Bit DRS_TWOWAY_SYNC is set in t.replicaFlags if and only
# if bit NTDSCONN_OPT_TWOWAY_SYNC is set in cn!options.
if (cn_conn.options & dsdb.NTDSCONN_OPT_TWOWAY_SYNC) != 0x0:
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_TWOWAY_SYNC) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_TWOWAY_SYNC
# Bits DRS_DISABLE_AUTO_SYNC and DRS_DISABLE_PERIODIC_SYNC are
# set in t.replicaFlags if and only if cn!enabledConnection = false.
if not cn_conn.is_enabled():
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_DISABLE_AUTO_SYNC) == 0x0):
t_repsFrom.replica_flags |= \
drsuapi.DRSUAPI_DRS_DISABLE_AUTO_SYNC
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_DISABLE_PERIODIC_SYNC) == 0x0):
t_repsFrom.replica_flags |= \
drsuapi.DRSUAPI_DRS_DISABLE_PERIODIC_SYNC
# If s and the local DC's nTDSDSA object are in the same site,
# cn!transportType has no value, or the RDN of cn!transportType
# is CN=IP:
#
# Bit DRS_MAIL_REP in t.replicaFlags is clear.
#
# t.uuidTransport = NULL GUID.
#
# t.uuidDsa = The GUID-based DNS name of s.
#
# Otherwise:
#
# Bit DRS_MAIL_REP in t.replicaFlags is set.
#
# If x is the object with dsname cn!transportType,
# t.uuidTransport = x!objectGUID.
#
# Let a be the attribute identified by
# x!transportAddressAttribute. If a is
# the dNSHostName attribute, t.uuidDsa = the GUID-based
# DNS name of s. Otherwise, t.uuidDsa = (s!parent)!a.
#
# It appears that the first statement i.e.
#
# "If s and the local DC's nTDSDSA object are in the same
# site, cn!transportType has no value, or the RDN of
# cn!transportType is CN=IP:"
#
# could be a slightly tighter statement if it had an "or"
# between each condition. I believe this should
# be interpreted as:
#
# IF (same-site) OR (no-value) OR (type-ip)
#
# because IP should be the primary transport mechanism
# (even in inter-site) and the absense of the transportType
# attribute should always imply IP no matter if its multi-site
#
# NOTE MS-TECH INCORRECT:
#
# All indications point to these statements above being
# incorrectly stated:
#
# t.uuidDsa = The GUID-based DNS name of s.
#
# Let a be the attribute identified by
# x!transportAddressAttribute. If a is
# the dNSHostName attribute, t.uuidDsa = the GUID-based
# DNS name of s. Otherwise, t.uuidDsa = (s!parent)!a.
#
# because the uuidDSA is a GUID and not a GUID-base DNS
# name. Nor can uuidDsa hold (s!parent)!a if not
# dNSHostName. What should have been said is:
#
# t.naDsa = The GUID-based DNS name of s
#
# That would also be correct if transportAddressAttribute
# were "mailAddress" because (naDsa) can also correctly
# hold the SMTP ISM service address.
#
nastr = "%s._msdcs.%s" % (s_dsa.dsa_guid, self.samdb.forest_dns_name())
# We're not currently supporting SMTP replication
# so is_smtp_replication_available() is currently
# always returning False
if ((same_site or
cn_conn.transport_dnstr is None or
cn_conn.transport_dnstr.find("CN=IP") == 0 or
not is_smtp_replication_available())):
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_MAIL_REP) != 0x0):
t_repsFrom.replica_flags &= ~drsuapi.DRSUAPI_DRS_MAIL_REP
t_repsFrom.transport_guid = misc.GUID()
# See (NOTE MS-TECH INCORRECT) above
if t_repsFrom.version == 0x1:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name1 != nastr:
t_repsFrom.dns_name1 = nastr
else:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name2 is None or \
t_repsFrom.dns_name1 != nastr or \
t_repsFrom.dns_name2 != nastr:
t_repsFrom.dns_name1 = nastr
t_repsFrom.dns_name2 = nastr
else:
# XXX This entire branch is NEVER used! Because we don't do SMTP!
# (see the if condition above). Just close your eyes here.
if ((t_repsFrom.replica_flags &
drsuapi.DRSUAPI_DRS_MAIL_REP) == 0x0):
t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_MAIL_REP
# We have a transport type but its not an
# object in the database
if cn_conn.transport_guid not in self.transport_table:
raise KCCError("Missing inter-site transport - (%s)" %
cn_conn.transport_dnstr)
x_transport = self.transport_table[str(cn_conn.transport_guid)]
if t_repsFrom.transport_guid != x_transport.guid:
t_repsFrom.transport_guid = x_transport.guid
# See (NOTE MS-TECH INCORRECT) above
if x_transport.address_attr == "dNSHostName":
if t_repsFrom.version == 0x1:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name1 != nastr:
t_repsFrom.dns_name1 = nastr
else:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name2 is None or \
t_repsFrom.dns_name1 != nastr or \
t_repsFrom.dns_name2 != nastr:
t_repsFrom.dns_name1 = nastr
t_repsFrom.dns_name2 = nastr
else:
# MS tech specification says we retrieve the named
# attribute in "transportAddressAttribute" from the parent of
# the DSA object
try:
pdnstr = s_dsa.get_parent_dnstr()
attrs = [x_transport.address_attr]
res = self.samdb.search(base=pdnstr, scope=ldb.SCOPE_BASE,
attrs=attrs)
except ldb.LdbError, (enum, estr):
raise KCCError(
"Unable to find attr (%s) for (%s) - (%s)" %
(x_transport.address_attr, pdnstr, estr))
msg = res[0]
nastr = str(msg[x_transport.address_attr][0])
# See (NOTE MS-TECH INCORRECT) above
if t_repsFrom.version == 0x1:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name1 != nastr:
t_repsFrom.dns_name1 = nastr
else:
if t_repsFrom.dns_name1 is None or \
t_repsFrom.dns_name2 is None or \
t_repsFrom.dns_name1 != nastr or \
t_repsFrom.dns_name2 != nastr:
t_repsFrom.dns_name1 = nastr
t_repsFrom.dns_name2 = nastr
if t_repsFrom.is_modified():
DEBUG_FN("modify_repsFrom(): %s" % t_repsFrom)
def is_repsFrom_implied(self, n_rep, cn_conn):
"""Given a NC replica and NTDS Connection, determine if the connection
implies a repsFrom tuple should be present from the source DSA listed
in the connection to the naming context
:param n_rep: NC replica
:param conn: NTDS Connection
::returns (True || False), source DSA:
"""
#XXX different conditions for "implies" than MS-ADTS 6.2.2
# NTDS Connection must satisfy all the following criteria
# to imply a repsFrom tuple is needed:
#
# cn!enabledConnection = true.
# cn!options does not contain NTDSCONN_OPT_RODC_TOPOLOGY.
# cn!fromServer references an nTDSDSA object.
s_dsa = None
if cn_conn.is_enabled() and not cn_conn.is_rodc_topology():
s_dnstr = cn_conn.get_from_dnstr()
if s_dnstr is not None:
s_dsa = self.get_dsa(s_dnstr)
# No DSA matching this source DN string?
if s_dsa is None:
return False, None
# To imply a repsFrom tuple is needed, each of these
# must be True:
#
# An NC replica of the NC "is present" on the DC to
# which the nTDSDSA object referenced by cn!fromServer
# corresponds.
#
# An NC replica of the NC "should be present" on
# the local DC
s_rep = s_dsa.get_current_replica(n_rep.nc_dnstr)
if s_rep is None or not s_rep.is_present():
return False, None
# To imply a repsFrom tuple is needed, each of these
# must be True:
#
# The NC replica on the DC referenced by cn!fromServer is
# a writable replica or the NC replica that "should be
# present" on the local DC is a partial replica.
#
# The NC is not a domain NC, the NC replica that
# "should be present" on the local DC is a partial
# replica, cn!transportType has no value, or
# cn!transportType has an RDN of CN=IP.
#
implied = (not s_rep.is_ro() or n_rep.is_partial()) and \
(not n_rep.is_domain() or
n_rep.is_partial() or
cn_conn.transport_dnstr is None or
cn_conn.transport_dnstr.find("CN=IP") == 0)
if implied:
return True, s_dsa
else:
return False, None
def translate_ntdsconn(self, current_dsa=None):
"""Adjust repsFrom to match NTDSConnections
This function adjusts values of repsFrom abstract attributes of NC
replicas on the local DC to match those implied by
nTDSConnection objects.
Based on [MS-ADTS] 6.2.2.5
:param current_dsa: optional DSA on whose behalf we are acting.
:return: None
"""
count = 0
if current_dsa is None:
current_dsa = self.my_dsa
if current_dsa.is_translate_ntdsconn_disabled():
DEBUG_FN("skipping translate_ntdsconn() "
"because disabling flag is set")
return
DEBUG_FN("translate_ntdsconn(): enter")
current_rep_table, needed_rep_table = current_dsa.get_rep_tables()
# Filled in with replicas we currently have that need deleting
delete_reps = set()
# We're using the MS notation names here to allow
# correlation back to the published algorithm.
#
# n_rep - NC replica (n)
# t_repsFrom - tuple (t) in n!repsFrom
# s_dsa - Source DSA of the replica. Defined as nTDSDSA
# object (s) such that (s!objectGUID = t.uuidDsa)
# In our IDL representation of repsFrom the (uuidDsa)
# attribute is called (source_dsa_obj_guid)
# cn_conn - (cn) is nTDSConnection object and child of the local
# DC's nTDSDSA object and (cn!fromServer = s)
# s_rep - source DSA replica of n
#
# If we have the replica and its not needed
# then we add it to the "to be deleted" list.
for dnstr in current_rep_table:
if dnstr not in needed_rep_table:
delete_reps.add(dnstr)
DEBUG_FN('current %d needed %d delete %d' % (len(current_rep_table),
len(needed_rep_table), len(delete_reps)))
if delete_reps:
DEBUG('deleting these reps: %s' % delete_reps)
for dnstr in delete_reps:
del current_rep_table[dnstr]
# Now perform the scan of replicas we'll need
# and compare any current repsFrom against the
# connections
for n_rep in needed_rep_table.values():
# load any repsFrom and fsmo roles as we'll
# need them during connection translation
n_rep.load_repsFrom(self.samdb)
n_rep.load_fsmo_roles(self.samdb)
# Loop thru the existing repsFrom tupples (if any)
# XXX This is a list and could contain duplicates
# (multiple load_repsFrom calls)
for t_repsFrom in n_rep.rep_repsFrom:
# for each tuple t in n!repsFrom, let s be the nTDSDSA
# object such that s!objectGUID = t.uuidDsa
guidstr = str(t_repsFrom.source_dsa_obj_guid)
s_dsa = self.get_dsa_by_guidstr(guidstr)
# Source dsa is gone from config (strange)
# so cleanup stale repsFrom for unlisted DSA
if s_dsa is None:
logger.warning("repsFrom source DSA guid (%s) not found" %
guidstr)
t_repsFrom.to_be_deleted = True
continue
s_dnstr = s_dsa.dsa_dnstr
# Retrieve my DSAs connection object (if it exists)
# that specifies the fromServer equivalent to
# the DSA that is specified in the repsFrom source
connections = current_dsa.get_connection_by_from_dnstr(s_dnstr)
count = 0
cn_conn = None
for con in connections:
if con.is_rodc_topology():
continue
cn_conn = con
# Let (cn) be the nTDSConnection object such that (cn)
# is a child of the local DC's nTDSDSA object and
# (cn!fromServer = s) and (cn!options) does not contain
# NTDSCONN_OPT_RODC_TOPOLOGY or NULL if no such (cn) exists.
# KCC removes this repsFrom tuple if any of the following
# is true:
# cn = NULL.
# [...]
#XXX varying possible interpretations of rodc_topology
if cn_conn is None:
t_repsFrom.to_be_deleted = True
continue
# [...] KCC removes this repsFrom tuple if:
#
# No NC replica of the NC "is present" on DSA that
# would be source of replica
#
# A writable replica of the NC "should be present" on
# the local DC, but a partial replica "is present" on
# the source DSA
s_rep = s_dsa.get_current_replica(n_rep.nc_dnstr)
if s_rep is None or not s_rep.is_present() or \
(not n_rep.is_ro() and s_rep.is_partial()):
t_repsFrom.to_be_deleted = True
continue
# If the KCC did not remove t from n!repsFrom, it updates t
self.modify_repsFrom(n_rep, t_repsFrom, s_rep, s_dsa, cn_conn)
# Loop thru connections and add implied repsFrom tuples
# for each NTDSConnection under our local DSA if the
# repsFrom is not already present
for cn_conn in current_dsa.connect_table.values():
implied, s_dsa = self.is_repsFrom_implied(n_rep, cn_conn)
if not implied:
continue
# Loop thru the existing repsFrom tupples (if any) and
# if we already have a tuple for this connection then
# no need to proceed to add. It will have been changed
# to have the correct attributes above
for t_repsFrom in n_rep.rep_repsFrom:
guidstr = str(t_repsFrom.source_dsa_obj_guid)
#XXX what?
if s_dsa is self.get_dsa_by_guidstr(guidstr):
s_dsa = None
break
if s_dsa is None:
continue
# Create a new RepsFromTo and proceed to modify
# it according to specification
t_repsFrom = RepsFromTo(n_rep.nc_dnstr)
t_repsFrom.source_dsa_obj_guid = s_dsa.dsa_guid
s_rep = s_dsa.get_current_replica(n_rep.nc_dnstr)
self.modify_repsFrom(n_rep, t_repsFrom, s_rep, s_dsa, cn_conn)
# Add to our NC repsFrom as this is newly computed
if t_repsFrom.is_modified():
n_rep.rep_repsFrom.append(t_repsFrom)
if self.readonly:
# Display any to be deleted or modified repsFrom
text = n_rep.dumpstr_to_be_deleted()
if text:
logger.info("TO BE DELETED:\n%s" % text)
text = n_rep.dumpstr_to_be_modified()
if text:
logger.info("TO BE MODIFIED:\n%s" % text)
# Peform deletion from our tables but perform
# no database modification
n_rep.commit_repsFrom(self.samdb, ro=True)
else:
# Commit any modified repsFrom to the NC replica
n_rep.commit_repsFrom(self.samdb)
def merge_failed_links(self):
"""Merge of kCCFailedLinks and kCCFailedLinks from bridgeheads.
The KCC on a writable DC attempts to merge the link and connection
failure information from bridgehead DCs in its own site to help it
identify failed bridgehead DCs.
Based on MS-ADTS 6.2.2.3.2 "Merge of kCCFailedLinks and kCCFailedLinks
from Bridgeheads"
:param ping: An oracle of current bridgehead availability
:return: None
"""
# 1. Queries every bridgehead server in your site (other than yourself)
# 2. For every ntDSConnection that references a server in a different
# site merge all the failure info
#
# XXX - not implemented yet
if self.attempt_live_connections:
debug.DEBUG_RED("merge_failed_links() is NOT IMPLEMENTED")
else:
DEBUG_FN("skipping merge_failed_links() because it requires "
"real network connections\n"
"and we weren't asked to --attempt-live-connections")
def setup_graph(self, part):
"""Set up an intersite graph
An intersite graph has a Vertex for each site object, a
MultiEdge for each SiteLink object, and a MutliEdgeSet for
each siteLinkBridge object (or implied siteLinkBridge). It
reflects the intersite topology in a slightly more abstract
graph form.
Roughly corresponds to MS-ADTS 6.2.2.3.4.3
:param part: a Partition object
:returns: an InterSiteGraph object
"""
guid_to_vertex = {}
# Create graph
g = IntersiteGraph()
# Add vertices
for site_guid, site in self.site_table.items():
vertex = Vertex(site, part)
vertex.guid = site_guid
vertex.ndrpacked_guid = ndr_pack(site.site_guid)
g.vertices.add(vertex)
if not guid_to_vertex.get(site_guid):
guid_to_vertex[site_guid] = []
guid_to_vertex[site_guid].append(vertex)
connected_vertices = set()
for transport_guid, transport in self.transport_table.items():
# Currently only ever "IP"
if transport.name != 'IP':
DEBUG_FN("setup_graph is ignoring transport %s" %
transport.name)
continue
for site_link_dn, site_link in self.sitelink_table.items():
new_edge = create_edge(transport_guid, site_link,
guid_to_vertex)
connected_vertices.update(new_edge.vertices)
g.edges.add(new_edge)
# If 'Bridge all site links' is enabled and Win2k3 bridges required
# is not set
# NTDSTRANSPORT_OPT_BRIDGES_REQUIRED 0x00000002
# No documentation for this however, ntdsapi.h appears to have:
# NTDSSETTINGS_OPT_W2K3_BRIDGES_REQUIRED = 0x00001000
if (((self.my_site.site_options & 0x00000002) == 0
and (self.my_site.site_options & 0x00001000) == 0)):
g.edge_set.add(create_auto_edge_set(g, transport_guid))
else:
# TODO get all site link bridges
for site_link_bridge in []:
g.edge_set.add(create_edge_set(g, transport_guid,
site_link_bridge))
g.connected_vertices = connected_vertices
#be less verbose in dot file output unless --debug
do_dot_files = opts.dot_files and opts.debug
dot_edges = []
for edge in g.edges:
for a, b in itertools.combinations(edge.vertices, 2):
dot_edges.append((a.site.site_dnstr, b.site.site_dnstr))
verify_properties = ()
verify_and_dot('site_edges', dot_edges, directed=False,
label=self.my_dsa_dnstr,
properties=verify_properties, debug=DEBUG,
verify=self.verify,
dot_files=self.dot_files)
return g
def get_bridgehead(self, site, part, transport, partial_ok, detect_failed):
"""Get a bridghead DC for a site.
Part of MS-ADTS 6.2.2.3.4.4
:param site: site object representing for which a bridgehead
DC is desired.
:param part: crossRef for NC to replicate.
:param transport: interSiteTransport object for replication
traffic.
:param partial_ok: True if a DC containing a partial
replica or a full replica will suffice, False if only
a full replica will suffice.
:param detect_failed: True to detect failed DCs and route
replication traffic around them, False to assume no DC
has failed.
:return: dsa object for the bridgehead DC or None
"""
bhs = self.get_all_bridgeheads(site, part, transport,
partial_ok, detect_failed)
if len(bhs) == 0:
debug.DEBUG_MAGENTA("get_bridgehead:\n\tsitedn=%s\n\tbhdn=None" %
site.site_dnstr)
return None
else:
debug.DEBUG_GREEN("get_bridgehead:\n\tsitedn=%s\n\tbhdn=%s" %
(site.site_dnstr, bhs[0].dsa_dnstr))
return bhs[0]
def get_all_bridgeheads(self, site, part, transport,
partial_ok, detect_failed):
"""Get all bridghead DCs on a site satisfying the given criteria
Part of MS-ADTS 6.2.2.3.4.4
:param site: site object representing the site for which
bridgehead DCs are desired.
:param part: partition for NC to replicate.
:param transport: interSiteTransport object for
replication traffic.
:param partial_ok: True if a DC containing a partial
replica or a full replica will suffice, False if
only a full replica will suffice.
:param detect_failed: True to detect failed DCs and route
replication traffic around them, FALSE to assume
no DC has failed.
:return: list of dsa object for available bridgehead DCs
"""
bhs = []
DEBUG_FN("get_all_bridgeheads: %s" % transport.name)
if 'Site-5' in site.site_dnstr:
debug.DEBUG_RED("get_all_bridgeheads with %s, part%s, "
"partial_ok %s detect_failed %s" %
(site.site_dnstr, part.partstr, partial_ok,
detect_failed))
DEBUG_FN(site.rw_dsa_table)
for dsa in site.rw_dsa_table.values():
pdnstr = dsa.get_parent_dnstr()
# IF t!bridgeheadServerListBL has one or more values and
# t!bridgeheadServerListBL does not contain a reference
# to the parent object of dc then skip dc
if ((len(transport.bridgehead_list) != 0 and
pdnstr not in transport.bridgehead_list)):
continue
# IF dc is in the same site as the local DC
# IF a replica of cr!nCName is not in the set of NC replicas
# that "should be present" on dc or a partial replica of the
# NC "should be present" but partialReplicasOkay = FALSE
# Skip dc
if self.my_site.same_site(dsa):
needed, ro, partial = part.should_be_present(dsa)
if not needed or (partial and not partial_ok):
continue
rep = dsa.get_current_replica(part.nc_dnstr)
# ELSE
# IF an NC replica of cr!nCName is not in the set of NC
# replicas that "are present" on dc or a partial replica of
# the NC "is present" but partialReplicasOkay = FALSE
# Skip dc
else:
rep = dsa.get_current_replica(part.nc_dnstr)
if rep is None or (rep.is_partial() and not partial_ok):
continue
# IF AmIRODC() and cr!nCName corresponds to default NC then
# Let dsaobj be the nTDSDSA object of the dc
# IF dsaobj.msDS-Behavior-Version < DS_DOMAIN_FUNCTION_2008
# Skip dc
if self.my_dsa.is_ro() and rep is not None and rep.is_default():
if not dsa.is_minimum_behavior(dsdb.DS_DOMAIN_FUNCTION_2008):
continue
# IF t!name != "IP" and the parent object of dc has no value for
# the attribute specified by t!transportAddressAttribute
# Skip dc
if transport.name != "IP":
# MS tech specification says we retrieve the named
# attribute in "transportAddressAttribute" from the parent
# of the DSA object
try:
attrs = [transport.address_attr]
res = self.samdb.search(base=pdnstr, scope=ldb.SCOPE_BASE,
attrs=attrs)
except ldb.LdbError, (enum, estr):
continue
msg = res[0]
if transport.address_attr not in msg:
continue
#XXX nastr is NEVER USED. It will be removed.
nastr = str(msg[transport.address_attr][0])
# IF BridgeheadDCFailed(dc!objectGUID, detectFailedDCs) = TRUE
# Skip dc
if self.is_bridgehead_failed(dsa, detect_failed):
DEBUG("bridgehead is failed")
continue
DEBUG_FN("get_all_bridgeheads: dsadn=%s" % dsa.dsa_dnstr)
bhs.append(dsa)
# IF bit NTDSSETTINGS_OPT_IS_RAND_BH_SELECTION_DISABLED is set in
# s!options
# SORT bhs such that all GC servers precede DCs that are not GC
# servers, and otherwise by ascending objectGUID
# ELSE
# SORT bhs in a random order
if site.is_random_bridgehead_disabled():
bhs.sort(sort_dsa_by_gc_and_guid)
else:
random.shuffle(bhs)
debug.DEBUG_YELLOW(bhs)
return bhs
def is_bridgehead_failed(self, dsa, detect_failed):
"""Determine whether a given DC is known to be in a failed state
:param dsa: the bridgehead to test
:param detect_failed: True to really check, False to assume no failure
:return: True if and only if the DC should be considered failed
Here we DEPART from the pseudo code spec which appears to be
wrong. It says, in full:
/***** BridgeheadDCFailed *****/
/* Determine whether a given DC is known to be in a failed state.
* IN: objectGUID - objectGUID of the DC's nTDSDSA object.
* IN: detectFailedDCs - TRUE if and only failed DC detection is
* enabled.
* RETURNS: TRUE if and only if the DC should be considered to be in a
* failed state.
*/
BridgeheadDCFailed(IN GUID objectGUID, IN bool detectFailedDCs) : bool
{
IF bit NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED is set in
the options attribute of the site settings object for the local
DC's site
RETURN FALSE
ELSEIF a tuple z exists in the kCCFailedLinks or
kCCFailedConnections variables such that z.UUIDDsa =
objectGUID, z.FailureCount > 1, and the current time -
z.TimeFirstFailure > 2 hours
RETURN TRUE
ELSE
RETURN detectFailedDCs
ENDIF
}
where you will see detectFailedDCs is not behaving as
advertised -- it is acting as a default return code in the
event that a failure is not detected, not a switch turning
detection on or off. Elsewhere the documentation seems to
concur with the comment rather than the code.
"""
if not detect_failed:
return False
# NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED = 0x00000008
# When DETECT_STALE_DISABLED, we can never know of if
# it's in a failed state
if self.my_site.site_options & 0x00000008:
return False
return self.is_stale_link_connection(dsa)
def create_connection(self, part, rbh, rsite, transport,
lbh, lsite, link_opt, link_sched,
partial_ok, detect_failed):
"""Create an nTDSConnection object as specified if it doesn't exist.
Part of MS-ADTS 6.2.2.3.4.5
:param part: crossRef object for the NC to replicate.
:param rbh: nTDSDSA object for DC to act as the
IDL_DRSGetNCChanges server (which is in a site other
than the local DC's site).
:param rsite: site of the rbh
:param transport: interSiteTransport object for the transport
to use for replication traffic.
:param lbh: nTDSDSA object for DC to act as the
IDL_DRSGetNCChanges client (which is in the local DC's site).
:param lsite: site of the lbh
:param link_opt: Replication parameters (aggregated siteLink options,
etc.)
:param link_sched: Schedule specifying the times at which
to begin replicating.
:partial_ok: True if bridgehead DCs containing partial
replicas of the NC are acceptable.
:param detect_failed: True to detect failed DCs and route
replication traffic around them, FALSE to assume no DC
has failed.
"""
rbhs_all = self.get_all_bridgeheads(rsite, part, transport,
partial_ok, False)
rbh_table = {x.dsa_dnstr: x for x in rbhs_all}
debug.DEBUG_GREY("rbhs_all: %s %s" % (len(rbhs_all),
[x.dsa_dnstr for x in rbhs_all]))
# MS-TECH says to compute rbhs_avail but then doesn't use it
# rbhs_avail = self.get_all_bridgeheads(rsite, part, transport,
# partial_ok, detect_failed)
lbhs_all = self.get_all_bridgeheads(lsite, part, transport,
partial_ok, False)
if lbh.is_ro():
lbhs_all.append(lbh)
debug.DEBUG_GREY("lbhs_all: %s %s" % (len(lbhs_all),
[x.dsa_dnstr for x in lbhs_all]))
# MS-TECH says to compute lbhs_avail but then doesn't use it
# lbhs_avail = self.get_all_bridgeheads(lsite, part, transport,
# partial_ok, detect_failed)
# FOR each nTDSConnection object cn such that the parent of cn is
# a DC in lbhsAll and cn!fromServer references a DC in rbhsAll
for ldsa in lbhs_all:
for cn in ldsa.connect_table.values():
rdsa = rbh_table.get(cn.from_dnstr)
if rdsa is None:
continue
debug.DEBUG_DARK_YELLOW("rdsa is %s" % rdsa.dsa_dnstr)
# IF bit NTDSCONN_OPT_IS_GENERATED is set in cn!options and
# NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options and
# cn!transportType references t
if ((cn.is_generated() and
not cn.is_rodc_topology() and
cn.transport_guid == transport.guid)):
# IF bit NTDSCONN_OPT_USER_OWNED_SCHEDULE is clear in
# cn!options and cn!schedule != sch
# Perform an originating update to set cn!schedule to
# sched
if ((not cn.is_user_owned_schedule() and
not cn.is_equivalent_schedule(link_sched))):
cn.schedule = link_sched
cn.set_modified(True)
# IF bits NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
# NTDSCONN_OPT_USE_NOTIFY are set in cn
if cn.is_override_notify_default() and \
cn.is_use_notify():
# IF bit NTDSSITELINK_OPT_USE_NOTIFY is clear in
# ri.Options
# Perform an originating update to clear bits
# NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
# NTDSCONN_OPT_USE_NOTIFY in cn!options
if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) == 0:
cn.options &= \
~(dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
dsdb.NTDSCONN_OPT_USE_NOTIFY)
cn.set_modified(True)
# ELSE
else:
# IF bit NTDSSITELINK_OPT_USE_NOTIFY is set in
# ri.Options
# Perform an originating update to set bits
# NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
# NTDSCONN_OPT_USE_NOTIFY in cn!options
if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) != 0:
cn.options |= \
(dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
dsdb.NTDSCONN_OPT_USE_NOTIFY)
cn.set_modified(True)
# IF bit NTDSCONN_OPT_TWOWAY_SYNC is set in cn!options
if cn.is_twoway_sync():
# IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is clear in
# ri.Options
# Perform an originating update to clear bit
# NTDSCONN_OPT_TWOWAY_SYNC in cn!options
if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) == 0:
cn.options &= ~dsdb.NTDSCONN_OPT_TWOWAY_SYNC
cn.set_modified(True)
# ELSE
else:
# IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is set in
# ri.Options
# Perform an originating update to set bit
# NTDSCONN_OPT_TWOWAY_SYNC in cn!options
if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) != 0:
cn.options |= dsdb.NTDSCONN_OPT_TWOWAY_SYNC
cn.set_modified(True)
# IF bit NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION is set
# in cn!options
if cn.is_intersite_compression_disabled():
# IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is clear
# in ri.Options
# Perform an originating update to clear bit
# NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in
# cn!options
if ((link_opt &
dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) == 0):
cn.options &= \
~dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION
cn.set_modified(True)
# ELSE
else:
# IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is set in
# ri.Options
# Perform an originating update to set bit
# NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in
# cn!options
if ((link_opt &
dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) != 0):
cn.options |= \
dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION
cn.set_modified(True)
# Display any modified connection
if self.readonly:
if cn.to_be_modified:
logger.info("TO BE MODIFIED:\n%s" % cn)
ldsa.commit_connections(self.samdb, ro=True)
else:
ldsa.commit_connections(self.samdb)
# ENDFOR
valid_connections = 0
# FOR each nTDSConnection object cn such that cn!parent is
# a DC in lbhsAll and cn!fromServer references a DC in rbhsAll
for ldsa in lbhs_all:
for cn in ldsa.connect_table.values():
rdsa = rbh_table.get(cn.from_dnstr)
if rdsa is None:
continue
debug.DEBUG_DARK_YELLOW("round 2: rdsa is %s" % rdsa.dsa_dnstr)
# IF (bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options or
# cn!transportType references t) and
# NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options
if (((not cn.is_generated() or
cn.transport_guid == transport.guid) and
not cn.is_rodc_topology())):
# LET rguid be the objectGUID of the nTDSDSA object
# referenced by cn!fromServer
# LET lguid be (cn!parent)!objectGUID
# IF BridgeheadDCFailed(rguid, detectFailedDCs) = FALSE and
# BridgeheadDCFailed(lguid, detectFailedDCs) = FALSE
# Increment cValidConnections by 1
if ((not self.is_bridgehead_failed(rdsa, detect_failed) and
not self.is_bridgehead_failed(ldsa, detect_failed))):
valid_connections += 1
# IF keepConnections does not contain cn!objectGUID
# APPEND cn!objectGUID to keepConnections
self.kept_connections.add(cn)
# ENDFOR
debug.DEBUG_RED("valid connections %d" % valid_connections)
DEBUG("kept_connections:\n%s" % (self.kept_connections,))
# IF cValidConnections = 0
if valid_connections == 0:
# LET opt be NTDSCONN_OPT_IS_GENERATED
opt = dsdb.NTDSCONN_OPT_IS_GENERATED
# IF bit NTDSSITELINK_OPT_USE_NOTIFY is set in ri.Options
# SET bits NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
# NTDSCONN_OPT_USE_NOTIFY in opt
if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) != 0:
opt |= (dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
dsdb.NTDSCONN_OPT_USE_NOTIFY)
# IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is set in ri.Options
# SET bit NTDSCONN_OPT_TWOWAY_SYNC opt
if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) != 0:
opt |= dsdb.NTDSCONN_OPT_TWOWAY_SYNC
# IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is set in
# ri.Options
# SET bit NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in opt
if ((link_opt &
dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) != 0):
opt |= dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION
# Perform an originating update to create a new nTDSConnection
# object cn that is a child of lbh, cn!enabledConnection = TRUE,
# cn!options = opt, cn!transportType is a reference to t,
# cn!fromServer is a reference to rbh, and cn!schedule = sch
DEBUG_FN("new connection, KCC dsa: %s" % self.my_dsa.dsa_dnstr)
cn = lbh.new_connection(opt, 0, transport,
rbh.dsa_dnstr, link_sched)
# Display any added connection
if self.readonly:
if cn.to_be_added:
logger.info("TO BE ADDED:\n%s" % cn)
lbh.commit_connections(self.samdb, ro=True)
else:
lbh.commit_connections(self.samdb)
# APPEND cn!objectGUID to keepConnections
self.kept_connections.add(cn)
def add_transports(self, vertex, local_vertex, graph, detect_failed):
"""Build a Vertex's transport lists
Each vertex has accept_red_red and accept_black lists that
list what transports they accept under various conditions. The
only transport that is ever accepted is IP, and a dummy extra
transport called "EDGE_TYPE_ALL".
Part of MS-ADTS 6.2.2.3.4.3 -- ColorVertices
:param vertex: the remote vertex we are thinking about
:param local_vertex: the vertex relating to the local site.
:param graph: the intersite graph
:param detect_failed: whether to detect failed links
:return: True if some bridgeheads were not found
"""
# The docs ([MS-ADTS] 6.2.2.3.4.3) say to use local_vertex
# here, but using vertex seems to make more sense. That is,
# the docs want this:
#
#bh = self.get_bridgehead(vertex.site, vertex.part, transport,
# local_vertex.is_black(), detect_failed)
#
# TODO WHY?????
vertex.accept_red_red = []
vertex.accept_black = []
found_failed = False
for t_guid, transport in self.transport_table.items():
if transport.name != 'IP':
#XXX well this is cheating a bit
logger.warning("WARNING: we are ignoring a transport named %r"
% transport.name)
continue
# FLAG_CR_NTDS_DOMAIN 0x00000002
if ((vertex.is_red() and transport.name != "IP" and
vertex.part.system_flags & 0x00000002)):
continue
if vertex not in graph.connected_vertices:
continue
partial_replica_okay = vertex.is_black()
bh = self.get_bridgehead(vertex.site, vertex.part, transport,
partial_replica_okay, detect_failed)
if bh is None:
found_failed = True
continue
vertex.accept_red_red.append(t_guid)
vertex.accept_black.append(t_guid)
# Add additional transport to allow another run of Dijkstra
vertex.accept_red_red.append("EDGE_TYPE_ALL")
vertex.accept_black.append("EDGE_TYPE_ALL")
return found_failed
def create_connections(self, graph, part, detect_failed):
"""Construct an NC replica graph for the NC identified by
the given crossRef, then create any additional nTDSConnection
objects required.
:param graph: site graph.
:param part: crossRef object for NC.
:param detect_failed: True to detect failed DCs and route
replication traffic around them, False to assume no DC
has failed.
Modifies self.kept_connections by adding any connections
deemed to be "in use".
::returns: (all_connected, found_failed_dc)
(all_connected) True if the resulting NC replica graph
connects all sites that need to be connected.
(found_failed_dc) True if one or more failed DCs were
detected.
"""
all_connected = True
found_failed = False
DEBUG_FN("create_connections(): enter\n"
"\tpartdn=%s\n\tdetect_failed=%s" %
(part.nc_dnstr, detect_failed))
# XXX - This is a highly abbreviated function from the MS-TECH
# ref. It creates connections between bridgeheads to all
# sites that have appropriate replicas. Thus we are not
# creating a minimum cost spanning tree but instead
# producing a fully connected tree. This should produce
# a full (albeit not optimal cost) replication topology.
my_vertex = Vertex(self.my_site, part)
my_vertex.color_vertex()
for v in graph.vertices:
v.color_vertex()
if self.add_transports(v, my_vertex, graph, False):
found_failed = True
# No NC replicas for this NC in the site of the local DC,
# so no nTDSConnection objects need be created
if my_vertex.is_white():
return all_connected, found_failed
edge_list, n_components = get_spanning_tree_edges(graph,
self.my_site,
label=part.partstr)
DEBUG_FN("%s Number of components: %d" %
(part.nc_dnstr, n_components))
if n_components > 1:
all_connected = False
# LET partialReplicaOkay be TRUE if and only if
# localSiteVertex.Color = COLOR.BLACK
partial_ok = my_vertex.is_black()
# Utilize the IP transport only for now
transport = self.ip_transport
DEBUG("edge_list %s" % edge_list)
for e in edge_list:
# XXX more accurate comparison?
if e.directed and e.vertices[0].site is self.my_site:
continue
if e.vertices[0].site is self.my_site:
rsite = e.vertices[1].site
else:
rsite = e.vertices[0].site
# We don't make connections to our own site as that
# is intrasite topology generator's job
if rsite is self.my_site:
DEBUG("rsite is my_site")
continue
# Determine bridgehead server in remote site
rbh = self.get_bridgehead(rsite, part, transport,
partial_ok, detect_failed)
if rbh is None:
continue
# RODC acts as an BH for itself
# IF AmIRODC() then
# LET lbh be the nTDSDSA object of the local DC
# ELSE
# LET lbh be the result of GetBridgeheadDC(localSiteVertex.ID,
# cr, t, partialReplicaOkay, detectFailedDCs)
if self.my_dsa.is_ro():
lsite = self.my_site
lbh = self.my_dsa
else:
lsite = self.my_site
lbh = self.get_bridgehead(lsite, part, transport,
partial_ok, detect_failed)
# TODO
if lbh is None:
debug.DEBUG_RED("DISASTER! lbh is None")
return False, True
debug.DEBUG_CYAN("SITES")
print lsite, rsite
debug.DEBUG_BLUE("vertices")
print e.vertices
debug.DEBUG_BLUE("bridgeheads")
print lbh, rbh
debug.DEBUG_BLUE("-" * 70)
sitelink = e.site_link
if sitelink is None:
link_opt = 0x0
link_sched = None
else:
link_opt = sitelink.options
link_sched = sitelink.schedule
self.create_connection(part, rbh, rsite, transport,
lbh, lsite, link_opt, link_sched,
partial_ok, detect_failed)
return all_connected, found_failed
def create_intersite_connections(self):
"""Computes an NC replica graph for each NC replica that "should be
present" on the local DC or "is present" on any DC in the same site
as the local DC. For each edge directed to an NC replica on such a
DC from an NC replica on a DC in another site, the KCC creates an
nTDSConnection object to imply that edge if one does not already
exist.
Modifies self.kept_connections - A set of nTDSConnection
objects for edges that are directed
to the local DC's site in one or more NC replica graphs.
returns: True if spanning trees were created for all NC replica
graphs, otherwise False.
"""
all_connected = True
self.kept_connections = set()
# LET crossRefList be the set containing each object o of class
# crossRef such that o is a child of the CN=Partitions child of the
# config NC
# FOR each crossRef object cr in crossRefList
# IF cr!enabled has a value and is false, or if FLAG_CR_NTDS_NC
# is clear in cr!systemFlags, skip cr.
# LET g be the GRAPH return of SetupGraph()
for part in self.part_table.values():
if not part.is_enabled():
continue
if part.is_foreign():
continue
graph = self.setup_graph(part)
# Create nTDSConnection objects, routing replication traffic
# around "failed" DCs.
found_failed = False
connected, found_failed = self.create_connections(graph,
part, True)
DEBUG("with detect_failed: connected %s Found failed %s" %
(connected, found_failed))
if not connected:
all_connected = False
if found_failed:
# One or more failed DCs preclude use of the ideal NC
# replica graph. Add connections for the ideal graph.
self.create_connections(graph, part, False)
return all_connected
def intersite(self):
"""The head method for generating the inter-site KCC replica
connection graph and attendant nTDSConnection objects
in the samdb.
Produces self.kept_connections set of NTDS Connections
that should be kept during subsequent pruning process.
::return (True or False): (True) if the produced NC replica
graph connects all sites that need to be connected
"""
# Retrieve my DSA
mydsa = self.my_dsa
mysite = self.my_site
all_connected = True
DEBUG_FN("intersite(): enter")
# Determine who is the ISTG
if self.readonly:
mysite.select_istg(self.samdb, mydsa, ro=True)
else:
mysite.select_istg(self.samdb, mydsa, ro=False)
# Test whether local site has topology disabled
if mysite.is_intersite_topology_disabled():
DEBUG_FN("intersite(): exit disabled all_connected=%d" %
all_connected)
return all_connected
if not mydsa.is_istg():
DEBUG_FN("intersite(): exit not istg all_connected=%d" %
all_connected)
return all_connected
self.merge_failed_links()
# For each NC with an NC replica that "should be present" on the
# local DC or "is present" on any DC in the same site as the
# local DC, the KCC constructs a site graph--a precursor to an NC
# replica graph. The site connectivity for a site graph is defined
# by objects of class interSiteTransport, siteLink, and
# siteLinkBridge in the config NC.
all_connected = self.create_intersite_connections()
DEBUG_FN("intersite(): exit all_connected=%d" % all_connected)
return all_connected
def update_rodc_connection(self):
"""Runs when the local DC is an RODC and updates the RODC NTFRS
connection object.
"""
# Given an nTDSConnection object cn1, such that cn1.options contains
# NTDSCONN_OPT_RODC_TOPOLOGY, and another nTDSConnection object cn2,
# does not contain NTDSCONN_OPT_RODC_TOPOLOGY, modify cn1 to ensure
# that the following is true:
#
# cn1.fromServer = cn2.fromServer
# cn1.schedule = cn2.schedule
#
# If no such cn2 can be found, cn1 is not modified.
# If no such cn1 can be found, nothing is modified by this task.
if not self.my_dsa.is_ro():
return
all_connections = self.my_dsa.connect_table.values()
ro_connections = [x for x in all_connections if x.is_rodc_topology()]
rw_connections = [x for x in all_connections
if x not in ro_connections]
# XXX here we are dealing with multiple RODC_TOPO connections,
# if they exist. It is not clear whether the spec means that
# or if it ever arises.
if rw_connections and ro_connections:
for con in ro_connections:
cn2 = rw_connections[0]
con.from_dnstr = cn2.from_dnstr
con.schedule = cn2.schedule
con.to_be_modified = True
self.my_dsa.commit_connections(self.samdb, ro=self.readonly)
def intrasite_max_node_edges(self, node_count):
"""Returns the maximum number of edges directed to a node in
the intrasite replica graph.
The KCC does not create more
than 50 edges directed to a single DC. To optimize replication,
we compute that each node should have n+2 total edges directed
to it such that (n) is the smallest non-negative integer
satisfying (node_count <= 2*(n*n) + 6*n + 7)
(If the number of edges is m (i.e. n + 2), that is the same as
2 * m*m - 2 * m + 3).
edges n nodecount
2 0 7
3 1 15
4 2 27
5 3 43
...
50 48 4903
:param node_count: total number of nodes in the replica graph
The intention is that there should be no more than 3 hops
between any two DSAs at a site. With up to 7 nodes the 2 edges
of the ring are enough; any configuration of extra edges with
8 nodes will be enough. It is less clear that the 3 hop
guarantee holds at e.g. 15 nodes in degenerate cases, but
those are quite unlikely given the extra edges are randomly
arranged.
"""
n = 0
while True:
if node_count <= (2 * (n * n) + (6 * n) + 7):
break
n = n + 1
n = n + 2
if n < 50:
return n
return 50
def construct_intrasite_graph(self, site_local, dc_local,
nc_x, gc_only, detect_stale):
# [MS-ADTS] 6.2.2.2
# We're using the MS notation names here to allow
# correlation back to the published algorithm.
#
# nc_x - naming context (x) that we are testing if it
# "should be present" on the local DC
# f_of_x - replica (f) found on a DC (s) for NC (x)
# dc_s - DC where f_of_x replica was found
# dc_local - local DC that potentially needs a replica
# (f_of_x)
# r_list - replica list R
# p_of_x - replica (p) is partial and found on a DC (s)
# for NC (x)
# l_of_x - replica (l) is the local replica for NC (x)
# that should appear on the local DC
# r_len = is length of replica list |R|
#
# If the DSA doesn't need a replica for this
# partition (NC x) then continue
needed, ro, partial = nc_x.should_be_present(dc_local)
debug.DEBUG_YELLOW("construct_intrasite_graph(): enter" +
"\n\tgc_only=%d" % gc_only +
"\n\tdetect_stale=%d" % detect_stale +
"\n\tneeded=%s" % needed +
"\n\tro=%s" % ro +
"\n\tpartial=%s" % partial +
"\n%s" % nc_x)
if not needed:
debug.DEBUG_RED("%s lacks 'should be present' status, "
"aborting construct_intersite_graph!" %
nc_x.nc_dnstr)
return
# Create a NCReplica that matches what the local replica
# should say. We'll use this below in our r_list
l_of_x = NCReplica(dc_local.dsa_dnstr, dc_local.dsa_guid,
nc_x.nc_dnstr)
l_of_x.identify_by_basedn(self.samdb)
l_of_x.rep_partial = partial
l_of_x.rep_ro = ro
# Add this replica that "should be present" to the
# needed replica table for this DSA
dc_local.add_needed_replica(l_of_x)
# Replica list
#
# Let R be a sequence containing each writable replica f of x
# such that f "is present" on a DC s satisfying the following
# criteria:
#
# * s is a writable DC other than the local DC.
#
# * s is in the same site as the local DC.
#
# * If x is a read-only full replica and x is a domain NC,
# then the DC's functional level is at least
# DS_BEHAVIOR_WIN2008.
#
# * Bit NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED is set
# in the options attribute of the site settings object for
# the local DC's site, or no tuple z exists in the
# kCCFailedLinks or kCCFailedConnections variables such
# that z.UUIDDsa is the objectGUID of the nTDSDSA object
# for s, z.FailureCount > 0, and the current time -
# z.TimeFirstFailure > 2 hours.
r_list = []
# We'll loop thru all the DSAs looking for
# writeable NC replicas that match the naming
# context dn for (nc_x)
#
for dc_s in self.my_site.dsa_table.values():
# If this partition (nc_x) doesn't appear as a
# replica (f_of_x) on (dc_s) then continue
if not nc_x.nc_dnstr in dc_s.current_rep_table:
continue
# Pull out the NCReplica (f) of (x) with the dn
# that matches NC (x) we are examining.
f_of_x = dc_s.current_rep_table[nc_x.nc_dnstr]
# Replica (f) of NC (x) must be writable
if f_of_x.is_ro():
continue
# Replica (f) of NC (x) must satisfy the
# "is present" criteria for DC (s) that
# it was found on
if not f_of_x.is_present():
continue
# DC (s) must be a writable DSA other than
# my local DC. In other words we'd only replicate
# from other writable DC
if dc_s.is_ro() or dc_s is dc_local:
continue
# Certain replica graphs are produced only
# for global catalogs, so test against
# method input parameter
if gc_only and not dc_s.is_gc():
continue
# DC (s) must be in the same site as the local DC
# as this is the intra-site algorithm. This is
# handled by virtue of placing DSAs in per
# site objects (see enclosing for() loop)
# If NC (x) is intended to be read-only full replica
# for a domain NC on the target DC then the source
# DC should have functional level at minimum WIN2008
#
# Effectively we're saying that in order to replicate
# to a targeted RODC (which was introduced in Windows 2008)
# then we have to replicate from a DC that is also minimally
# at that level.
#
# You can also see this requirement in the MS special
# considerations for RODC which state that to deploy
# an RODC, at least one writable domain controller in
# the domain must be running Windows Server 2008
if ro and not partial and nc_x.nc_type == NCType.domain:
if not dc_s.is_minimum_behavior(dsdb.DS_DOMAIN_FUNCTION_2008):
continue
# If we haven't been told to turn off stale connection
# detection and this dsa has a stale connection then
# continue
if detect_stale and self.is_stale_link_connection(dc_s):
continue
# Replica meets criteria. Add it to table indexed
# by the GUID of the DC that it appears on
r_list.append(f_of_x)
# If a partial (not full) replica of NC (x) "should be present"
# on the local DC, append to R each partial replica (p of x)
# such that p "is present" on a DC satisfying the same
# criteria defined above for full replica DCs.
#
# XXX This loop and the previous one differ only in whether
# the replica is partial or not. here we only accept partial
# (because we're partial); before we only accepted full. Order
# doen't matter (the list is sorted a few lines down) so these
# loops could easily be merged. Or this could be a helper
# function.
if partial:
# Now we loop thru all the DSAs looking for
# partial NC replicas that match the naming
# context dn for (NC x)
for dc_s in self.my_site.dsa_table.values():
# If this partition NC (x) doesn't appear as a
# replica (p) of NC (x) on the dsa DC (s) then
# continue
if not nc_x.nc_dnstr in dc_s.current_rep_table:
continue
# Pull out the NCReplica with the dn that
# matches NC (x) we are examining.
p_of_x = dc_s.current_rep_table[nc_x.nc_dnstr]
# Replica (p) of NC (x) must be partial
if not p_of_x.is_partial():
continue
# Replica (p) of NC (x) must satisfy the
# "is present" criteria for DC (s) that
# it was found on
if not p_of_x.is_present():
continue
# DC (s) must be a writable DSA other than
# my DSA. In other words we'd only replicate
# from other writable DSA
if dc_s.is_ro() or dc_s is dc_local:
continue
# Certain replica graphs are produced only
# for global catalogs, so test against
# method input parameter
if gc_only and not dc_s.is_gc():
continue
# If we haven't been told to turn off stale connection
# detection and this dsa has a stale connection then
# continue
if detect_stale and self.is_stale_link_connection(dc_s):
continue
# Replica meets criteria. Add it to table indexed
# by the GUID of the DSA that it appears on
r_list.append(p_of_x)
# Append to R the NC replica that "should be present"
# on the local DC
r_list.append(l_of_x)
r_list.sort(sort_replica_by_dsa_guid)
r_len = len(r_list)
max_node_edges = self.intrasite_max_node_edges(r_len)
# Add a node for each r_list element to the replica graph
graph_list = []
for rep in r_list:
node = GraphNode(rep.rep_dsa_dnstr, max_node_edges)
graph_list.append(node)
# For each r(i) from (0 <= i < |R|-1)
i = 0
while i < (r_len-1):
# Add an edge from r(i) to r(i+1) if r(i) is a full
# replica or r(i+1) is a partial replica
if not r_list[i].is_partial() or r_list[i+1].is_partial():
graph_list[i+1].add_edge_from(r_list[i].rep_dsa_dnstr)
# Add an edge from r(i+1) to r(i) if r(i+1) is a full
# replica or ri is a partial replica.
if not r_list[i+1].is_partial() or r_list[i].is_partial():
graph_list[i].add_edge_from(r_list[i+1].rep_dsa_dnstr)
i = i + 1
# Add an edge from r|R|-1 to r0 if r|R|-1 is a full replica
# or r0 is a partial replica.
if not r_list[r_len-1].is_partial() or r_list[0].is_partial():
graph_list[0].add_edge_from(r_list[r_len-1].rep_dsa_dnstr)
# Add an edge from r0 to r|R|-1 if r0 is a full replica or
# r|R|-1 is a partial replica.
if not r_list[0].is_partial() or r_list[r_len-1].is_partial():
graph_list[r_len-1].add_edge_from(r_list[0].rep_dsa_dnstr)
DEBUG("r_list is length %s" % len(r_list))
DEBUG('\n'.join(str((x.rep_dsa_guid, x.rep_dsa_dnstr))
for x in r_list))
do_dot_files = self.dot_files and self.debug
if self.verify or do_dot_files:
dot_edges = []
dot_vertices = set()
for v1 in graph_list:
dot_vertices.add(v1.dsa_dnstr)
for v2 in v1.edge_from:
dot_edges.append((v2, v1.dsa_dnstr))
dot_vertices.add(v2)
verify_properties = ('connected', 'directed_double_ring_or_small')
verify_and_dot('intrasite_pre_ntdscon', dot_edges, dot_vertices,
label='%s__%s__%s' % (site_local.site_dnstr,
nctype_lut[nc_x.nc_type],
nc_x.nc_dnstr),
properties=verify_properties, debug=DEBUG,
verify=self.verify,
dot_files=do_dot_files, directed=True)
# For each existing nTDSConnection object implying an edge
# from rj of R to ri such that j != i, an edge from rj to ri
# is not already in the graph, and the total edges directed
# to ri is less than n+2, the KCC adds that edge to the graph.
for vertex in graph_list:
dsa = self.my_site.dsa_table[vertex.dsa_dnstr]
for connect in dsa.connect_table.values():
remote = connect.from_dnstr
if remote in self.my_site.dsa_table:
vertex.add_edge_from(remote)
DEBUG('reps are: %s' % ' '.join(x.rep_dsa_dnstr for x in r_list))
DEBUG('dsas are: %s' % ' '.join(x.dsa_dnstr for x in graph_list))
for tnode in graph_list:
# To optimize replication latency in sites with many NC
# replicas, the KCC adds new edges directed to ri to bring
# the total edges to n+2, where the NC replica rk of R
# from which the edge is directed is chosen at random such
# that k != i and an edge from rk to ri is not already in
# the graph.
#
# Note that the KCC tech ref does not give a number for
# the definition of "sites with many NC replicas". At a
# bare minimum to satisfy n+2 edges directed at a node we
# have to have at least three replicas in |R| (i.e. if n
# is zero then at least replicas from two other graph
# nodes may direct edges to us).
if r_len >= 3 and not tnode.has_sufficient_edges():
candidates = [x for x in graph_list if
(x is not tnode and
x.dsa_dnstr not in tnode.edge_from)]
debug.DEBUG_BLUE("looking for random link for %s. r_len %d, "
"graph len %d candidates %d"
% (tnode.dsa_dnstr, r_len, len(graph_list),
len(candidates)))
DEBUG("candidates %s" % [x.dsa_dnstr for x in candidates])
while candidates and not tnode.has_sufficient_edges():
other = random.choice(candidates)
DEBUG("trying to add candidate %s" % other.dsa_dstr)
if not tnode.add_edge_from(other):
debug.DEBUG_RED("could not add %s" % other.dsa_dstr)
candidates.remove(other)
else:
DEBUG_FN("not adding links to %s: nodes %s, links is %s/%s" %
(tnode.dsa_dnstr, r_len, len(tnode.edge_from),
tnode.max_edges))
# Print the graph node in debug mode
DEBUG_FN("%s" % tnode)
# For each edge directed to the local DC, ensure a nTDSConnection
# points to us that satisfies the KCC criteria
if tnode.dsa_dnstr == dc_local.dsa_dnstr:
tnode.add_connections_from_edges(dc_local)
if self.verify or do_dot_files:
dot_edges = []
dot_vertices = set()
for v1 in graph_list:
dot_vertices.add(v1.dsa_dnstr)
for v2 in v1.edge_from:
dot_edges.append((v2, v1.dsa_dnstr))
dot_vertices.add(v2)
verify_properties = ('connected', 'directed_double_ring_or_small')
verify_and_dot('intrasite_post_ntdscon', dot_edges, dot_vertices,
label='%s__%s__%s' % (site_local.site_dnstr,
nctype_lut[nc_x.nc_type],
nc_x.nc_dnstr),
properties=verify_properties, debug=DEBUG,
verify=self.verify,
dot_files=do_dot_files, directed=True)
def intrasite(self):
"""The head method for generating the intra-site KCC replica
connection graph and attendant nTDSConnection objects
in the samdb
"""
# Retrieve my DSA
mydsa = self.my_dsa
DEBUG_FN("intrasite(): enter")
# Test whether local site has topology disabled
mysite = self.my_site
if mysite.is_intrasite_topology_disabled():
return
detect_stale = (not mysite.is_detect_stale_disabled())
for connect in mydsa.connect_table.values():
if connect.to_be_added:
debug.DEBUG_CYAN("TO BE ADDED:\n%s" % connect)
# Loop thru all the partitions, with gc_only False
for partdn, part in self.part_table.items():
self.construct_intrasite_graph(mysite, mydsa, part, False,
detect_stale)
for connect in mydsa.connect_table.values():
if connect.to_be_added:
debug.DEBUG_BLUE("TO BE ADDED:\n%s" % connect)
# If the DC is a GC server, the KCC constructs an additional NC
# replica graph (and creates nTDSConnection objects) for the
# config NC as above, except that only NC replicas that "are present"
# on GC servers are added to R.
for connect in mydsa.connect_table.values():
if connect.to_be_added:
debug.DEBUG_YELLOW("TO BE ADDED:\n%s" % connect)
# Do it again, with gc_only True
for partdn, part in self.part_table.items():
if part.is_config():
self.construct_intrasite_graph(mysite, mydsa, part, True,
detect_stale)
# The DC repeats the NC replica graph computation and nTDSConnection
# creation for each of the NC replica graphs, this time assuming
# that no DC has failed. It does so by re-executing the steps as
# if the bit NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED were
# set in the options attribute of the site settings object for
# the local DC's site. (ie. we set "detec_stale" flag to False)
for connect in mydsa.connect_table.values():
if connect.to_be_added:
debug.DEBUG_BLUE("TO BE ADDED:\n%s" % connect)
# Loop thru all the partitions.
for partdn, part in self.part_table.items():
self.construct_intrasite_graph(mysite, mydsa, part, False,
False) # don't detect stale
# If the DC is a GC server, the KCC constructs an additional NC
# replica graph (and creates nTDSConnection objects) for the
# config NC as above, except that only NC replicas that "are present"
# on GC servers are added to R.
for connect in mydsa.connect_table.values():
if connect.to_be_added:
debug.DEBUG_RED("TO BE ADDED:\n%s" % connect)
for partdn, part in self.part_table.items():
if part.is_config():
self.construct_intrasite_graph(mysite, mydsa, part, True,
False) # don't detect stale
if self.readonly:
# Display any to be added or modified repsFrom
for connect in mydsa.connect_table.values():
if connect.to_be_deleted:
logger.info("TO BE DELETED:\n%s" % connect)
if connect.to_be_modified:
logger.info("TO BE MODIFIED:\n%s" % connect)
if connect.to_be_added:
debug.DEBUG_GREEN("TO BE ADDED:\n%s" % connect)
mydsa.commit_connections(self.samdb, ro=True)
else:
# Commit any newly created connections to the samdb
mydsa.commit_connections(self.samdb)
def list_dsas(self):
"""Compile a comprehensive list of DSA DNs
These are all the DSAs on all the sites that KCC would be
dealing with.
This method is not idempotent and may not work correctly in
sequence with KCC.run().
:return: a list of DSA DN strings.
"""
self.load_my_site()
self.load_my_dsa()
self.load_all_sites()
self.load_all_partitions()
self.load_all_transports()
self.load_all_sitelinks()
dsas = []
for site in self.site_table.values():
dsas.extend([dsa.dsa_dnstr.replace('CN=NTDS Settings,', '', 1)
for dsa in site.dsa_table.values()])
return dsas
def load_samdb(self, dburl, lp, creds):
"""Load the database using an url, loadparm, and credentials
:param dburl: a database url.
:param lp: a loadparm object.
:param cred: a Credentials object.
"""
self.samdb = SamDB(url=dburl,
session_info=system_session(),
credentials=creds, lp=lp)
def plot_all_connections(self, basename, verify_properties=()):
verify = verify_properties and self.verify
plot = self.dot_files
if not (verify or plot):
return
dot_edges = []
dot_vertices = []
edge_colours = []
vertex_colours = []
for dsa in self.dsa_by_dnstr.values():
dot_vertices.append(dsa.dsa_dnstr)
if dsa.is_ro():
vertex_colours.append('#cc0000')
else:
vertex_colours.append('#0000cc')
for con in dsa.connect_table.values():
if con.is_rodc_topology():
edge_colours.append('red')
else:
edge_colours.append('blue')
dot_edges.append((con.from_dnstr, dsa.dsa_dnstr))
verify_and_dot(basename, dot_edges, vertices=dot_vertices,
label=self.my_dsa_dnstr, properties=verify_properties,
debug=DEBUG, verify=verify, dot_files=plot,
directed=True, edge_colors=edge_colours,
vertex_colors=vertex_colours)
def run(self, dburl, lp, creds, forced_local_dsa=None,
forget_local_links=False, forget_intersite_links=False):
"""Method to perform a complete run of the KCC and
produce an updated topology for subsequent NC replica
syncronization between domain controllers
"""
# We may already have a samdb setup if we are
# currently importing an ldif for a test run
if self.samdb is None:
try:
self.load_samdb(dburl, lp, creds)
except ldb.LdbError, (num, msg):
logger.error("Unable to open sam database %s : %s" %
(dburl, msg))
return 1
if forced_local_dsa:
self.samdb.set_ntds_settings_dn("CN=NTDS Settings,%s" %
forced_local_dsa)
try:
# Setup
self.load_my_site()
self.load_my_dsa()
self.load_all_sites()
self.load_all_partitions()
self.load_all_transports()
self.load_all_sitelinks()
if self.verify or self.dot_files:
guid_to_dnstr = {}
for site in self.site_table.values():
guid_to_dnstr.update((str(dsa.dsa_guid), dnstr)
for dnstr, dsa
in site.dsa_table.items())
self.plot_all_connections('dsa_initial')
dot_edges = []
current_reps, needed_reps = self.my_dsa.get_rep_tables()
for dnstr, c_rep in current_reps.items():
DEBUG("c_rep %s" % c_rep)
dot_edges.append((self.my_dsa.dsa_dnstr, dnstr))
verify_and_dot('dsa_repsFrom_initial', dot_edges,
directed=True, label=self.my_dsa_dnstr,
properties=(), debug=DEBUG, verify=self.verify,
dot_files=self.dot_files)
dot_edges = []
for site in self.site_table.values():
for dsa in site.dsa_table.values():
current_reps, needed_reps = dsa.get_rep_tables()
for dn_str, rep in current_reps.items():
for reps_from in rep.rep_repsFrom:
DEBUG("rep %s" % rep)
dsa_guid = str(reps_from.source_dsa_obj_guid)
dsa_dn = guid_to_dnstr[dsa_guid]
dot_edges.append((dsa.dsa_dnstr, dsa_dn))
verify_and_dot('dsa_repsFrom_initial_all', dot_edges,
directed=True, label=self.my_dsa_dnstr,
properties=(), debug=DEBUG, verify=self.verify,
dot_files=self.dot_files)
dot_edges = []
for link in self.sitelink_table.values():
for a, b in itertools.combinations(link.site_list, 2):
dot_edges.append((str(a), str(b)))
properties = ('connected',)
verify_and_dot('dsa_sitelink_initial', dot_edges,
directed=False,
label=self.my_dsa_dnstr, properties=properties,
debug=DEBUG, verify=self.verify,
dot_files=self.dot_files)
if forget_local_links:
for dsa in self.my_site.dsa_table.values():
dsa.connect_table = {k: v for k, v in
dsa.connect_table.items()
if v.is_rodc_topology()}
self.plot_all_connections('dsa_forgotten_local')
if forget_intersite_links:
for site in self.site_table.values():
for dsa in site.dsa_table.values():
dsa.connect_table = {k: v for k, v in
dsa.connect_table.items()
if site is self.my_site and
v.is_rodc_topology()}
self.plot_all_connections('dsa_forgotten_all')
# These are the published steps (in order) for the
# MS-TECH description of the KCC algorithm ([MS-ADTS] 6.2.2)
# Step 1
self.refresh_failed_links_connections()
# Step 2
self.intrasite()
# Step 3
all_connected = self.intersite()
# Step 4
self.remove_unneeded_ntdsconn(all_connected)
# Step 5
self.translate_ntdsconn()
# Step 6
self.remove_unneeded_failed_links_connections()
# Step 7
self.update_rodc_connection()
if self.verify or self.dot_files:
self.plot_all_connections('dsa_final',
('connected', 'forest_of_rings'))
debug.DEBUG_MAGENTA("there are %d dsa guids" %
len(guid_to_dnstr))
dot_edges = []
edge_colors = []
my_dnstr = self.my_dsa.dsa_dnstr
current_reps, needed_reps = self.my_dsa.get_rep_tables()
for dnstr, n_rep in needed_reps.items():
for reps_from in n_rep.rep_repsFrom:
guid_str = str(reps_from.source_dsa_obj_guid)
dot_edges.append((my_dnstr, guid_to_dnstr[guid_str]))
edge_colors.append('#' + str(n_rep.nc_guid)[:6])
verify_and_dot('dsa_repsFrom_final', dot_edges, directed=True,
label=self.my_dsa_dnstr,
properties=(), debug=DEBUG, verify=self.verify,
dot_files=self.dot_files,
edge_colors=edge_colors)
dot_edges = []
for site in self.site_table.values():
for dsa in site.dsa_table.values():
current_reps, needed_reps = dsa.get_rep_tables()
for n_rep in needed_reps.values():
for reps_from in n_rep.rep_repsFrom:
dsa_guid = str(reps_from.source_dsa_obj_guid)
dsa_dn = guid_to_dnstr[dsa_guid]
dot_edges.append((dsa.dsa_dnstr, dsa_dn))
verify_and_dot('dsa_repsFrom_final_all', dot_edges,
directed=True, label=self.my_dsa_dnstr,
properties=(), debug=DEBUG, verify=self.verify,
dot_files=self.dot_files)
except:
raise
return 0
def import_ldif(self, dburl, lp, creds, ldif_file):
"""Import all objects and attributes that are relevent
to the KCC algorithms from a previously exported LDIF file.
The point of this function is to allow a programmer/debugger to
import an LDIF file with non-security relevent information that
was previously extracted from a DC database. The LDIF file is used
to create a temporary abbreviated database. The KCC algorithm can
then run against this abbreviated database for debug or test
verification that the topology generated is computationally the
same between different OSes and algorithms.
:param dburl: path to the temporary abbreviated db to create
:param ldif_file: path to the ldif file to import
"""
try:
self.samdb = ldif_utils.ldif_to_samdb(dburl, lp, ldif_file,
self.forced_local_dsa)
except ldif_utils.LdifError, e:
print e
return 1
return 0
def export_ldif(self, dburl, lp, creds, ldif_file):
"""Routine to extract all objects and attributes that are relevent
to the KCC algorithms from a DC database.
The point of this function is to allow a programmer/debugger to
extract an LDIF file with non-security relevent information from
a DC database. The LDIF file can then be used to "import" via
the import_ldif() function this file into a temporary abbreviated
database. The KCC algorithm can then run against this abbreviated
database for debug or test verification that the topology generated
is computationally the same between different OSes and algorithms.
:param dburl: LDAP database URL to extract info from
:param ldif_file: output LDIF file name to create
"""
try:
ldif_utils.samdb_to_ldif_file(self.samdb, dburl, lp, creds,
ldif_file)
except ldif_utils.LdifError, e:
print e
return 1
return 0
def get_spanning_tree_edges(graph, my_site, label=None):
# Phase 1: Run Dijkstra's to get a list of internal edges, which are
# just the shortest-paths connecting colored vertices
internal_edges = set()
for e_set in graph.edge_set:
edgeType = None
for v in graph.vertices:
v.edges = []
# All con_type in an edge set is the same
for e in e_set.edges:
edgeType = e.con_type
for v in e.vertices:
v.edges.append(e)
if opts.verify or opts.dot_files:
graph_edges = [(a.site.site_dnstr, b.site.site_dnstr)
for a, b in
itertools.chain(
*(itertools.combinations(edge.vertices, 2)
for edge in e_set.edges))]
graph_nodes = [v.site.site_dnstr for v in graph.vertices]
if opts.dot_files and opts.debug:
write_dot_file('edgeset_%s' % (edgeType,), graph_edges,
vertices=graph_nodes, label=label)
if opts.verify:
verify_graph('spanning tree edge set %s' % edgeType,
graph_edges, vertices=graph_nodes,
properties=('complete', 'connected'),
debug=DEBUG)
# Run dijkstra's algorithm with just the red vertices as seeds
# Seed from the full replicas
dijkstra(graph, edgeType, False)
# Process edge set
process_edge_set(graph, e_set, internal_edges)
# Run dijkstra's algorithm with red and black vertices as the seeds
# Seed from both full and partial replicas
dijkstra(graph, edgeType, True)
# Process edge set
process_edge_set(graph, e_set, internal_edges)
# All vertices have root/component as itself
setup_vertices(graph)
process_edge_set(graph, None, internal_edges)
if opts.verify or opts.dot_files:
graph_edges = [(e.v1.site.site_dnstr, e.v2.site.site_dnstr)
for e in internal_edges]
graph_nodes = [v.site.site_dnstr for v in graph.vertices]
verify_properties = ('multi_edge_forest',)
verify_and_dot('prekruskal', graph_edges, graph_nodes, label=label,
properties=verify_properties, debug=DEBUG,
verify=opts.verify,
dot_files=opts.dot_files)
# Phase 2: Run Kruskal's on the internal edges
output_edges, components = kruskal(graph, internal_edges)
# This recalculates the cost for the path connecting the
# closest red vertex. Ignoring types is fine because NO
# suboptimal edge should exist in the graph
dijkstra(graph, "EDGE_TYPE_ALL", False) # TODO rename
# Phase 3: Process the output
for v in graph.vertices:
if v.is_red():
v.dist_to_red = 0
else:
v.dist_to_red = v.repl_info.cost
if opts.verify or opts.dot_files:
graph_edges = [(e.v1.site.site_dnstr, e.v2.site.site_dnstr)
for e in internal_edges]
graph_nodes = [v.site.site_dnstr for v in graph.vertices]
verify_properties = ('multi_edge_forest',)
verify_and_dot('postkruskal', graph_edges, graph_nodes,
label=label, properties=verify_properties,
debug=DEBUG, verify=opts.verify,
dot_files=opts.dot_files)
# Ensure only one-way connections for partial-replicas,
# and make sure they point the right way.
edge_list = []
for edge in output_edges:
# We know these edges only have two endpoints because we made
# them.
v, w = edge.vertices
if v.site is my_site or w.site is my_site:
if (((v.is_black() or w.is_black()) and
v.dist_to_red != MAX_DWORD)):
edge.directed = True
if w.dist_to_red < v.dist_to_red:
edge.vertices[:] = w, v
edge_list.append(edge)
if opts.verify or opts.dot_files:
graph_edges = [[x.site.site_dnstr for x in e.vertices]
for e in edge_list]
#add the reverse edge if not directed.
graph_edges.extend([x.site.site_dnstr
for x in reversed(e.vertices)]
for e in edge_list if not e.directed)
graph_nodes = [x.site.site_dnstr for x in graph.vertices]
verify_properties = ()
verify_and_dot('post-one-way-partial', graph_edges, graph_nodes,
label=label, properties=verify_properties,
debug=DEBUG, verify=opts.verify,
directed=True,
dot_files=opts.dot_files)
# count the components
return edge_list, components
def sort_replica_by_dsa_guid(rep1, rep2):
"""Helper to sort NCReplicas by their DSA guids
The guids need to be sorted in their NDR form.
:param rep1: An NC replica
:param rep2: Another replica
:return: -1, 0, or 1, indicating sort order.
"""
return cmp(ndr_pack(rep1.rep_dsa_guid), ndr_pack(rep2.rep_dsa_guid))
def sort_dsa_by_gc_and_guid(dsa1, dsa2):
"""Helper to sort DSAs by guid global catalog status
GC DSAs come before non-GC DSAs, other than that, the guids are
sorted in NDR form.
:param dsa1: A DSA object
:param dsa2: Another DSA
:return: -1, 0, or 1, indicating sort order.
"""
if dsa1.is_gc() and not dsa2.is_gc():
return -1
if not dsa1.is_gc() and dsa2.is_gc():
return +1
return cmp(ndr_pack(dsa1.dsa_guid), ndr_pack(dsa2.dsa_guid))
def is_smtp_replication_available():
"""Can the KCC use SMTP replication?
Currently always returns false because Samba doesn't implement
SMTP transfer for NC changes between DCs.
:return: Boolean (always False)
"""
return False
def create_edge(con_type, site_link, guid_to_vertex):
e = MultiEdge()
e.site_link = site_link
e.vertices = []
for site_guid in site_link.site_list:
if str(site_guid) in guid_to_vertex:
e.vertices.extend(guid_to_vertex.get(str(site_guid)))
e.repl_info.cost = site_link.cost
e.repl_info.options = site_link.options
e.repl_info.interval = site_link.interval
e.repl_info.schedule = convert_schedule_to_repltimes(site_link.schedule)
e.con_type = con_type
e.directed = False
return e
def create_auto_edge_set(graph, transport):
e_set = MultiEdgeSet()
# use a NULL guid, not associated with a SiteLinkBridge object
e_set.guid = misc.GUID()
for site_link in graph.edges:
if site_link.con_type == transport:
e_set.edges.append(site_link)
return e_set
def create_edge_set(graph, transport, site_link_bridge):
# TODO not implemented - need to store all site link bridges
e_set = MultiEdgeSet()
# e_set.guid = site_link_bridge
return e_set
def setup_vertices(graph):
for v in graph.vertices:
if v.is_white():
v.repl_info.cost = MAX_DWORD
v.root = None
v.component_id = None
else:
v.repl_info.cost = 0
v.root = v
v.component_id = v
v.repl_info.interval = 0
v.repl_info.options = 0xFFFFFFFF
v.repl_info.schedule = None # TODO highly suspicious
v.demoted = False
def dijkstra(graph, edge_type, include_black):
queue = []
setup_dijkstra(graph, edge_type, include_black, queue)
while len(queue) > 0:
cost, guid, vertex = heapq.heappop(queue)
for edge in vertex.edges:
for v in edge.vertices:
if v is not vertex:
# add new path from vertex to v
try_new_path(graph, queue, vertex, edge, v)
def setup_dijkstra(graph, edge_type, include_black, queue):
setup_vertices(graph)
for vertex in graph.vertices:
if vertex.is_white():
continue
if (((vertex.is_black() and not include_black)
or edge_type not in vertex.accept_black
or edge_type not in vertex.accept_red_red)):
vertex.repl_info.cost = MAX_DWORD
vertex.root = None # NULL GUID
vertex.demoted = True # Demoted appears not to be used
else:
heapq.heappush(queue, (vertex.repl_info.cost, vertex.guid, vertex))
def try_new_path(graph, queue, vfrom, edge, vto):
newRI = ReplInfo()
# What this function checks is that there is a valid time frame for
# which replication can actually occur, despite being adequately
# connected
intersect = combine_repl_info(vfrom.repl_info, edge.repl_info, newRI)
# If the new path costs more than the current, then ignore the edge
if newRI.cost > vto.repl_info.cost:
return
if newRI.cost < vto.repl_info.cost and not intersect:
return
new_duration = total_schedule(newRI.schedule)
old_duration = total_schedule(vto.repl_info.schedule)
# Cheaper or longer schedule
if newRI.cost < vto.repl_info.cost or new_duration > old_duration:
vto.root = vfrom.root
vto.component_id = vfrom.component_id
vto.repl_info = newRI
heapq.heappush(queue, (vto.repl_info.cost, vto.guid, vto))
def check_demote_vertex(vertex, edge_type):
if vertex.is_white():
return
# Accepts neither red-red nor black edges, demote
if ((edge_type not in vertex.accept_black and
edge_type not in vertex.accept_red_red)):
vertex.repl_info.cost = MAX_DWORD
vertex.root = None
vertex.demoted = True # Demoted appears not to be used
def undemote_vertex(vertex):
if vertex.is_white():
return
vertex.repl_info.cost = 0
vertex.root = vertex
vertex.demoted = False
def process_edge_set(graph, e_set, internal_edges):
if e_set is None:
for edge in graph.edges:
for vertex in edge.vertices:
check_demote_vertex(vertex, edge.con_type)
process_edge(graph, edge, internal_edges)
for vertex in edge.vertices:
undemote_vertex(vertex)
else:
for edge in e_set.edges:
process_edge(graph, edge, internal_edges)
def process_edge(graph, examine, internal_edges):
# Find the set of all vertices touches the edge to examine
vertices = []
for v in examine.vertices:
# Append a 4-tuple of color, repl cost, guid and vertex
vertices.append((v.color, v.repl_info.cost, v.ndrpacked_guid, v))
# Sort by color, lower
DEBUG("vertices is %s" % vertices)
vertices.sort()
color, cost, guid, bestv = vertices[0]
# Add to internal edges an edge from every colored vertex to bestV
for v in examine.vertices:
if v.component_id is None or v.root is None:
continue
# Only add edge if valid inter-tree edge - needs a root and
# different components
if ((bestv.component_id is not None and
bestv.root is not None and
v.component_id is not None and
v.root is not None and
bestv.component_id != v.component_id)):
add_int_edge(graph, internal_edges, examine, bestv, v)
# Add internal edge, endpoints are roots of the vertices to pass in
# and are always colored
def add_int_edge(graph, internal_edges, examine, v1, v2):
root1 = v1.root
root2 = v2.root
red_red = False
if root1.is_red() and root2.is_red():
red_red = True
if red_red:
if ((examine.con_type not in root1.accept_red_red
or examine.con_type not in root2.accept_red_red)):
return
elif (examine.con_type not in root1.accept_black
or examine.con_type not in root2.accept_black):
return
ri = ReplInfo()
ri2 = ReplInfo()
# Create the transitive replInfo for the two trees and this edge
if not combine_repl_info(v1.repl_info, v2.repl_info, ri):
return
# ri is now initialized
if not combine_repl_info(ri, examine.repl_info, ri2):
return
newIntEdge = InternalEdge(root1, root2, red_red, ri2, examine.con_type,
examine.site_link)
# Order by vertex guid
#XXX guid comparison using ndr_pack
if newIntEdge.v1.ndrpacked_guid > newIntEdge.v2.ndrpacked_guid:
newIntEdge.v1 = root2
newIntEdge.v2 = root1
internal_edges.add(newIntEdge)
def kruskal(graph, edges):
for v in graph.vertices:
v.edges = []
components = set([x for x in graph.vertices if not x.is_white()])
edges = list(edges)
# Sorted based on internal comparison function of internal edge
edges.sort()
#XXX expected_num_tree_edges is never used
expected_num_tree_edges = 0 # TODO this value makes little sense
count_edges = 0
output_edges = []
index = 0
while index < len(edges): # TODO and num_components > 1
e = edges[index]
parent1 = find_component(e.v1)
parent2 = find_component(e.v2)
if parent1 is not parent2:
count_edges += 1
add_out_edge(graph, output_edges, e)
parent1.component_id = parent2
components.discard(parent1)
index += 1
return output_edges, len(components)
def find_component(vertex):
if vertex.component_id is vertex:
return vertex
current = vertex
while current.component_id is not current:
current = current.component_id
root = current
current = vertex
while current.component_id is not root:
n = current.component_id
current.component_id = root
current = n
return root
def add_out_edge(graph, output_edges, e):
v1 = e.v1
v2 = e.v2
# This multi-edge is a 'real' edge with no GUID
ee = MultiEdge()
ee.directed = False
ee.site_link = e.site_link
ee.vertices.append(v1)
ee.vertices.append(v2)
ee.con_type = e.e_type
ee.repl_info = e.repl_info
output_edges.append(ee)
v1.edges.append(ee)
v2.edges.append(ee)
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