slapo-retcode man page

slapo-retcode — return code overlay to slapd




The retcode overlay to slapd(8) is useful to test the behavior of clients when server-generated erroneous and/or unusual responses occur, e.g. error codes, referrals,  excessive response times and so on.

The error responses are generated according to different strategies.

In the first case, all operations targeted at a specific configurable subtree cause the object related to the request DN to be looked up and checked for return code data: a response code, plus an optional textual message, an optional configurable delay, an optional matched DN field, and, when the response code is "referral", a (list of) referral(s).

Well-known response codes from standard track documents are provided in retcode.conf, which can be included after instantiating the overlay.

In the second case, objects of classes inherited from  the errAbsObject, like errObject or errAuxObject, when returned as intermediate responses of a search request, are changed into the response dictated by their content.

A third mode causes objects to be looked up from the underlying database  to discover if their class inherits from errABsObject; in that case, their content is used to compute the corresponding response.

The behavior is disabled by using the manageDSAit control (RFC 3296); in that case, the resulting object, either present in the directory  or dynamically generated by the overlay, or contained in the request, is handled as usual.

The config directives that are specific to the retcode overlay must be prefixed by retcode-, to avoid conflicts with directives specific to the underlying database or to other stacked overlays.  The following specific directives  can be used to configure the retcode overlay:

retcode-parent <DN>

This directive defines the parent DN where dynamically generated entries reside. If not defined, the suffix of the database is used.

retcode-item <RDN> <errCode> [op=<oplist>] [text=<message>] [ref=<referral>] [sleeptime=<sec>] [matched=<DN>] [unsolicited=<OID>[:<data>]] [flags=[{pre|post}-]disconnect[,...]]

A dynamically generated entry, located below retcode-parent. The errCode is the number of the response code; it can be in any format supported by strtol(3). The optional oplist is a list of operations that cause response code generation; if absent, all operations are affected. The matched field is the matched DN that is returned along with the error, while the text field is an optional diagnostics message. The ref field is only allowed for the referral  response code. The sleeptime field causes slapd(8) to sleep the specified number of seconds before proceeding  with the operation. The unsolicited field can be used to cause the return of an RFC 4511 unsolicited response message; if OID is not "0", an extended response is generated, with the optional data appended. If flags contains disconnect, or pre-disconnect, slapd(8) disconnects abruptly, without notice; post-disconnect causes disconnection right after sending response as appropriate.


Enables exploitation of in-directory stored errAbsObject. May result in a lot of unnecessary overhead.

retcode-sleep [-]<n>

Defines a sleep time in seconds that is spent before actually handling any operation. If negative, a random time between 0 and the absolute value of the argument is used.


The retcode overlay utilizes the "return code" schema described herein.  This schema is specifically designed for use with this overlay and is not intended to be used otherwise. It is also noted that the schema described here is a work in progress, and hence subject to change without notice. The schema is loaded automatically by the overlay.

The schema includes a number of object classes and associated attribute types as described below.

The error code:

   NAME ( 'errCode' )
   DESC 'LDAP error code'
   EQUALITY integerMatch
   ORDERING integerOrderingMatch

The operations that trigger the response code:

   NAME ( 'errOp' )
   DESC 'Operations the errObject applies to'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch

The text message:

   NAME ( 'errText' )
   DESC 'LDAP error textual description'
   EQUALITY caseIgnoreMatch
   SUBSTR caseIgnoreSubstringsMatch

The sleep time before the response is actually returned to the client:

   NAME ( 'errSleepTime' )
   DESC 'Time to wait before returning the error'
   EQUALITY integerMatch

The matched DN returned to the client:

   NAME ( 'errMatchedDN' )
   DESC 'Value to be returned as matched DN'
   EQUALITY distinguishedNameMatch

The OID to be returned as extended response OID in RFC 4511 unsolicited responses ("0" generates a regular response with msgid set to 0):

   NAME ( 'errUnsolicitedOID' )
   DESC 'OID to be returned within unsolicited response'
   EQUALITY objectIdentifierMatch

The octet string to be returned as extended response data in RFC 4511 unsolicited response:

   NAME ( 'errUnsolicitedData' )
   DESC 'Data to be returned within unsolicited response'

If TRUE, slapd(8) disconnects abruptly without notice; if FALSE, it disconnects after sending response as appropriate:

   NAME ( 'errDisconnect' )
   DESC 'Disconnect without notice'

The abstract class that triggers the overlay:

   NAME ( 'errAbsObject' )
   MUST ( errCode )
   MAY ( cn $ description $ errOp $ errText $ errSleepTime
       $ errMatchedDN ) )

The standalone structural objectclass for specifically created data:

   NAME ( 'errObject' )
   SUP errAbsObject STRUCTURAL )

The auxiliary objectclass to alter the behavior of existing objects:

   NAME ( 'errAuxObject' )
   SUP errAbsObject AUXILIARY )


overlay         retcode
retcode-parent  "ou=RetCodes,dc=example,dc=com"

# retcode.conf is found in tests/data/ of the source tree
include         ./retcode.conf

# Wait 10 seconds, then return success (0x00)
retcode-item    "cn=Success after 10 seconds" 0x00 sleeptime=10
# Wait 10 seconds, then return timelimitExceeded (0x03)
retcode-item    "cn=Timelimit after 10 seconds" 0x03 sleeptime=10



default slapd configuration file

See Also

slapd.conf(5), slapd-config(5), slapd(8). The slapo-retcode(5) overlay supports dynamic configuration via back-config.


This module was written in 2005 by Pierangelo Masarati for SysNet s.n.c.

Referenced By


2016/02/05 OpenLDAP 2.4.44