Bug 9101 - Problem processing linked AD attributes with attribute-syntax 127
Problem processing linked AD attributes with attribute-syntax
Status: NEW
Product: Samba 4.0
Classification: Unclassified
4.0 beta4
x86 Linux
: P5 normal
: ---
Assigned To: Andrew Bartlett
Depends on:
  Show dependency treegraph
Reported: 2012-08-17 20:51 UTC by Paul Tabashov
Modified: 2015-07-24 08:29 UTC (History)
3 users (show)

See Also:


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Description Paul Tabashov 2012-08-17 20:51:20 UTC
My specific case is this:
- Windows 2003 AD domain
- Has Exchange 2010 in it with according schema changes in AD

 When trying to join Samba4 server to the domain, it fails with the following messages:

../source4/dsdb/samdb/ldb_modules/linked_attributes.c:164: Failed to find GUID for dn (null)
replmd_op_callback failure. Error is: Invalid DN syntax
Failed to apply records: Failed to find GUID for (null): Invalid DN syntax
Failed to commit objects: WERR_GENERAL_FAILURE

 When I tried to debug the issue, I see that it does fail on processing attributes for Exchange-related objects. I think that the issue is that the definitions of these attributes like say msExchOWATranscodingFileTypesBL have the following set:
  attribute-Syntax  ->
  oMSyntax          ->   127

From what I see in the data itself (from debug) and what I read here - http://www.informit.com/articles/article.aspx?p=26136&seqNum=5 , it seems like this calls for a specific syntax of these attributes, which doesn't seem to be handled by code in Samba4. 
From the link above:

This syntax stores a distinguished name along with a string. Active Directory keeps the DN up-to-date. The format is S:character count:string:DN (e.g., S:5: hello:someDN).

What I see in my data is the raw value for the attribute being something like this (company-specific information replaced with XXXX):

S:8:       .:<GUID=a7beeb89-ef10-4585-874b-89c9a338df1b>;CN=XXXXX,CN=OWA Mailbox Policies,CN=XXXXXX Corporation,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=XXXXX,DC=XXXXX

It looks like the function ldb_dn_from_ldb_val in lib/ldb/common/ldb_dn.c is doing the parsing, but it is not an expected syntax so ldb_dn struct it returns is not formed properly.

I am willing to provide more information that might be needed.

I can also try to give a shot at coming up with the patch, but will need to have some assistance as to what parts of code might need to be looked at as I do not fully grasp the impact of this with my limited knowledge of AD.

Comment 1 Andrew Bartlett 2012-08-17 22:33:14 UTC
See the last entry in the table at: source4/dsdb/schema/schema_syntax.c:2616

This is where we match the the incoming syntax values with function pointers to parse them.

To run the join under gdb, run eg:

gdb --args /usr/bin/python bin/samba-tool domain join ....

Then you can break in those functions, and follow them until they fail to parse the DN.  Or add DEBUG() messages in the source.
Comment 2 Jay D. Carter 2013-05-23 20:40:46 UTC
Please see my post:

...which appears to be the same issue. Exchange version is 2007, AD domain is Windows 2003.

from my level 10 debug log:

     a:<GUID=redacted>;CN=owa (Default Web Site),
 CN=HTTP,CN=Protocols,CN=servername,CN=Servers,CN=Exchange Administrative Group (
 FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First Organization,CN=Microsoft 
msExchOWATranscodingMimeTypes: S:52:                                          
          a:<GUID=redacted>;CN=owa (Default Web Si
 te),CN=HTTP,CN=Protocols,CN=servername,CN=Servers,CN=Exchange Administrative Gro
 up (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First Organization,CN=Micros
 oft Exchange,CN=Services,CN=Configuration,DC=jaydcarter,DC=com,DC=local
msExchOWATranscodingMimeTypes: S:58:                                          
                a:<GUID=redacted>;CN=owa (Default 
 Web Site),CN=HTTP,CN=Protocols,CN=servername,CN=Servers,CN=Exchange Administrati
 ve Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First Organization,CN=
 Microsoft Exchange,CN=Services,CN=Configuration,DC=jaydcarter,DC=com,DC=local
msExchOWATranscodingFlags: 1
msExchVersion: 4535486012416
../source4/dsdb/samdb/ldb_modules/linked_attributes.c:164: Failed to find GUID for dn (null)
replmd_op_callback failure. Error is: Invalid DN syntax
Failed to apply records: Failed to find GUID for (null): Invalid DN syntax
Failed to commit objects: WERR_GENERAL_FAILURE
Join failed - cleaning up

I can provide more info or run additional tests - just let me know.

Comment 3 Jay D. Carter 2013-05-23 20:41:35 UTC
Sorry,forgot to mention my issue occurs in Samba 4.0.5