sin/samba-mirror
1
0
Fork 0
mirror of https://github.com/samba-team/samba.git synced 2024-12-23 17:34:34 +03:00
Code

dbcheck: add find_missing_forward_links_from_backlinks()

Browse Source 
find_missing_forward_links_from_backlinks() finds and returns missing forward-links by
searching all for all objects that link to the object in the backlink attribute.

This will be used in the next commit to restore forward links in a corrupted
forward link attribute by passing the missing backling objects to
err_recover_forward_links().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13228

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
This commit is contained in:
Ralph Boehme 2018-01-25 14:48:55 +01:00 committed by Stefan Metzmacher
parent 182fb3c4c9
commit d59f201388
1 changed files with 96 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
python/samba/dbchecker.py
View File

@ -987,6 +987,102 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
return False
def find_missing_forward_links_from_backlinks(self, obj,
forward_attr,
forward_syntax,
backlink_attr,
forward_unique_dict):
'''Find all backlinks linking to obj_guid_str not already in forward_unique_dict'''
missing_forward_links = []
error_count = 0
if backlink_attr is None:
return (missing_forward_links, error_count)
if forward_syntax != ldb.SYNTAX_DN:
self.report("Not checking for missing forward links for syntax: %s",
forward_syntax)
return (missing_forward_links, error_count)
try:
obj_guid = obj['objectGUID'][0]
obj_guid_str = str(ndr_unpack(misc.GUID, obj_guid))
filter = "(%s=<GUID=%s>)" % (backlink_attr, obj_guid_str)
res = self.samdb.search(expression=filter,
scope=ldb.SCOPE_SUBTREE, attrs=["objectGUID"],
controls=["extended_dn:1:1",
"search_options:1:2",
"paged_results:1:1000"])
except ldb.LdbError, (enum, estr):
raise
for r in res:
target_dn = dsdb_Dn(self.samdb, r.dn.extended_str(), forward_syntax)
guid = target_dn.dn.get_extended_component("GUID")
guidstr = str(misc.GUID(guid))
if guidstr in forward_unique_dict:
continue
# A valid forward link looks like this:
#
# <GUID=9f92d30a-fc23-11e4-a5f6-30be15454808>;
# <RMD_ADDTIME=131607546230000000>;
# <RMD_CHANGETIME=131607546230000000>;
# <RMD_FLAGS=0>;
# <RMD_INVOCID=4e4496a3-7fb8-4f97-8a33-d238db8b5e2d>;
# <RMD_LOCAL_USN=3765>;
# <RMD_ORIGINATING_USN=3765>;
# <RMD_VERSION=1>;
# <SID=S-1-5-21-4177067393-1453636373-93818738-1124>;
# CN=unsorted-u8,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp
#
# Note that versions older than Samba 4.8 create
# links with RMD_VERSION=0.
#
# Try to get the local_usn and time from objectClass
# if possible and fallback to any other one.
repl = ndr_unpack(drsblobs.replPropertyMetaDataBlob,
obj['replPropertyMetadata'][0])
for o in repl.ctr.array:
local_usn = o.local_usn
t = o.originating_change_time
if o.attid == drsuapi.DRSUAPI_ATTID_objectClass:
break
# We use a magic invocationID for restoring missing
# forward links to recover from bug #13228.
# This should allow some more future magic to fix the
# problem.
#
# It also means it looses the conflict resolution
# against almost every real invocation, if the
# version is also 0.
originating_invocid = misc.GUID("ffffffff-4700-4700-4700-000000b13228")
originating_usn = 1
rmd_addtime = t
rmd_changetime = t
rmd_flags = 0
rmd_invocid = originating_invocid
rmd_originating_usn = originating_usn
rmd_local_usn = local_usn
rmd_version = 0
target_dn.dn.set_extended_component("RMD_ADDTIME", str(rmd_addtime))
target_dn.dn.set_extended_component("RMD_CHANGETIME", str(rmd_changetime))
target_dn.dn.set_extended_component("RMD_FLAGS", str(rmd_flags))
target_dn.dn.set_extended_component("RMD_INVOCID", ndr_pack(rmd_invocid))
target_dn.dn.set_extended_component("RMD_ORIGINATING_USN", str(rmd_originating_usn))
target_dn.dn.set_extended_component("RMD_LOCAL_USN", str(rmd_local_usn))
target_dn.dn.set_extended_component("RMD_VERSION", str(rmd_version))
error_count += 1
missing_forward_links.append(target_dn)
return (missing_forward_links, error_count)
def check_dn(self, obj, attrname, syntax_oid):
'''check a DN attribute for correctness'''
error_count = 0