.lf 1 stdin
.TH SLAPO-ACCESSLOG 5 "2020/04/28" "OpenLDAP 2.4.50"
.\" Copyright 2005-2020 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.\" $OpenLDAP$
.SH NAME
slapo\-accesslog \- Access Logging overlay to slapd
.SH SYNOPSIS
/etc/openldap/slapd.conf
.SH DESCRIPTION
The Access Logging overlay can be used to record all accesses to a given
backend database on another database. This allows all of the activity on
a given database to be reviewed using arbitrary LDAP queries, instead of
just logging to local flat text files. Configuration options are available
for selecting a subset of operation types to log, and to automatically
prune older log records from the logging database.  Log records are stored
with audit schema (see below) to assure their readability whether viewed
as LDIF or in raw form.
.SH CONFIGURATION
These
.B slapd.conf
options apply to the Access Logging overlay.
They should appear after the
.B overlay
directive.
.TP
.B logdb <suffix>
Specify the suffix of a database to be used for storing the log records.
The specified database must be defined elsewhere in the configuration.
The access controls
on the log database should prevent general access. The suffix entry
of the log database will be created automatically by this overlay. The log
entries will be generated as the immediate children of the suffix entry.
.TP
.B logops <operations>
Specify which types of operations to log. The valid operation types are
abandon, add, bind, compare, delete, extended, modify, modrdn, search,
and unbind. Aliases for common sets of operations are also available:
.RS
.TP
.B writes
add, delete, modify, modrdn
.TP
.B reads
compare, search
.TP
.B session
abandon, bind, unbind
.TP
.B all
all operations
.RE
.TP
.B logbase <operations> <baseDN>
Specify a set of operations that will only be logged if they occur under
a specific subtree of the database. The operation types are as above for
the
.B logops
setting, and delimited by a '|' character.
.TP
.B logold <filter>
Specify a filter for matching against Deleted and Modified entries. If
the entry matches the filter, the old contents of the entry will be
logged along with the current request.
.TP
.B logoldattr <attr> ...
Specify a list of attributes whose old contents are always logged in
Modify and ModRDN requests. Usually only the contents of attributes that were
actually modified will be logged; by default no old attributes are logged
for ModRDN requests.
.TP
.B logpurge <age> <interval>
Specify the maximum age for log entries to be retained in the database,
and how often to scan the database for old entries. Both the
.B age
and
.B interval
are specified as a time span in days, hours, minutes, and seconds. The
time format is [ddd+]hh:mm[:ss] i.e., the days and seconds components are
optional but hours and minutes are required. Except for days, which can
be up to 5 digits, each numeric field must be exactly two digits. For example
.RS
.RS
.PD 0
.TP
logpurge 2+00:00 1+00:00
.RE
.PD
would specify that the log database should be scanned every day for old
entries, and entries older than two days should be deleted. When using a
log database that supports ordered indexing on generalizedTime attributes,
specifying an eq index on the
.B reqStart
attribute will greatly benefit the performance of the purge operation.
.RE
.TP
.B logsuccess TRUE | FALSE
If set to TRUE then log records will only be generated for successful
requests, i.e., requests that produce a result code of 0 (LDAP_SUCCESS).
If FALSE, log records are generated for all requests whether they
succeed or not. The default is FALSE.

.SH EXAMPLES
.LP
.nf
	database bdb
	suffix dc=example,dc=com
	\...
	overlay accesslog
	logdb cn=log
	logops writes reads
	logbase search|compare ou=testing,dc=example,dc=com
	logold (objectclass=person)

	database bdb
	suffix cn=log
	\...
	index reqStart eq
	access to *
	  by dn.base="cn=admin,dc=example,dc=com" read
.fi

.SH SCHEMA
The
.B accesslog
overlay utilizes the "audit" schema described herein.
This schema is specifically designed for
.B accesslog
auditing and is not intended to be used otherwise.  It is also
noted that the schema described here is
.I a work in
.IR 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.

There is
a basic
.B auditObject
class from which two additional classes,
.B auditReadObject
and
.B auditWriteObject
are derived. Object classes for each type of LDAP operation are further
derived from these classes. This object class hierarchy is designed to
allow flexible yet efficient searches of the log based on either a specific
operation type's class, or on more general classifications. The definition
of the
.B auditObject
class is as follows:
.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.1
    NAME 'auditObject'
    DESC 'OpenLDAP request auditing'
    SUP top STRUCTURAL
    MUST ( reqStart $ reqType $ reqSession )
    MAY ( reqDN $ reqAuthzID $ reqControls $ reqRespControls $
        reqEnd $ reqResult $ reqMessage $ reqReferral ) )
.RE
.P
Note that all of the OIDs used in the logging schema currently reside
under the OpenLDAP Experimental branch. It is anticipated that they
will migrate to a Standard branch in the future.

An overview of the attributes follows:
.B reqStart
and
.B reqEnd
provide the start and end time of the operation, respectively. They use
generalizedTime syntax. The
.B reqStart
attribute is also used as the RDN for each log entry.

The
.B reqType
attribute is a simple string containing the type of operation
being logged, e.g.
.BR add ,
.BR delete ,
.BR search ,
etc. For extended operations, the type also includes the OID of the
extended operation, e.g.
.B extended(1.1.1.1)

The
.B reqSession
attribute is an implementation-specific identifier that is common to
all the operations associated with the same LDAP session. Currently this
is slapd's internal connection ID, stored in decimal.

The
.B reqDN
attribute is the distinguishedName of the target of the operation. E.g., for
a Bind request, this is the Bind DN. For an Add request, this is the DN
of the entry being added. For a Search request, this is the base DN of
the search.

The
.B reqAuthzID
attribute is the distinguishedName of the user that performed the operation.
This will usually be the same name as was established at the start of a
session by a Bind request (if any) but may be altered in various
circumstances.

The
.B reqControls
and
.B reqRespControls
attributes carry any controls sent by the client on the request and returned
by the server in the response, respectively. The attribute values are just
uninterpreted octet strings.

The
.B reqResult
attribute is the numeric LDAP result code of the operation, indicating
either success or a particular LDAP error code. An error code may be
accompanied by a text error message which will be recorded in the
.B reqMessage
attribute.

The
.B reqReferral
attribute carries any referrals that were returned with the result of the
request.

Operation-specific classes are defined with additional attributes to carry
all of the relevant parameters associated with the operation:

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.4
    NAME 'auditAbandon'
    DESC 'Abandon operation'
    SUP auditObject STRUCTURAL
    MUST reqId )
.RE
.P
For the
.B Abandon
operation the
.B reqId
attribute contains the message ID of the request that was abandoned.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.5
    NAME 'auditAdd'
    DESC 'Add operation'
    SUP auditWriteObject STRUCTURAL
    MUST reqMod )
.RE
.P
The
.B Add
class inherits from the
.B auditWriteObject
class. The Add and Modify classes are very similar. The
.B reqMod
attribute carries all of the attributes of the original entry being added.
(Or in the case of a Modify operation, all of the modifications being
performed.) The values are formatted as
.RS
.PD 0
.TP
attribute:<+|\-|=|#> [ value]
.RE
.RE
.PD
Where '+' indicates an Add of a value, '\-' for Delete, '=' for Replace,
and '#' for Increment. In an Add operation, all of the reqMod values will
have the '+' designator.
.P
.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.6
    NAME 'auditBind'
    DESC 'Bind operation'
    SUP auditObject STRUCTURAL
    MUST ( reqVersion $ reqMethod ) )
.RE
.P
The
.B Bind
class includes the
.B reqVersion
attribute which contains the LDAP protocol version specified in the Bind
as well as the
.B reqMethod
attribute which contains the Bind Method used in the Bind. This will be
the string
.B SIMPLE
for LDAP Simple Binds or
.B SASL(<mech>)
for SASL Binds.
Note that unless configured as a global overlay, only Simple Binds using
DNs that reside in the current database will be logged.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.7
    NAME 'auditCompare'
    DESC 'Compare operation'
    SUP auditObject STRUCTURAL
    MUST reqAssertion )
.RE
.P
For the
.B Compare
operation the
.B reqAssertion
attribute carries the Attribute Value Assertion used in the compare request.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.8
    NAME 'auditDelete'
    DESC 'Delete operation'
    SUP auditWriteObject STRUCTURAL
    MAY reqOld )
.RE
.P
The
.B Delete
operation needs no further parameters. However, the
.B reqOld
attribute may optionally be used to record the contents of the entry prior
to its deletion. The values are formatted as
.RS
.PD 0
.TP
attribute: value
.RE
.PD
The
.B reqOld
attribute is only populated if the entry being deleted matches the
configured
.B logold
filter.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.9
    NAME 'auditModify'
    DESC 'Modify operation'
    SUP auditWriteObject STRUCTURAL
    MAY reqOld MUST reqMod )
.RE
.P
The
.B Modify
operation contains a description of modifications in the
.B reqMod
attribute, which was already described above in the Add operation. It may
optionally contain the previous contents of any modified attributes in the
.B reqOld
attribute, using the same format as described above for the Delete operation.
The
.B reqOld
attribute is only populated if the entry being modified matches the
configured
.B logold
filter.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.10
    NAME 'auditModRDN'
    DESC 'ModRDN operation'
    SUP auditWriteObject STRUCTURAL
    MUST ( reqNewRDN $ reqDeleteOldRDN )
    MAY ( reqNewSuperior $ reqOld ) )
.RE
.P
The
.B ModRDN
class uses the
.B reqNewRDN
attribute to carry the new RDN of the request.
The
.B reqDeleteOldRDN
attribute is a Boolean value showing
.B TRUE
if the old RDN was deleted from the entry, or
.B FALSE
if the old RDN was preserved.
The
.B reqNewSuperior
attribute carries the DN of the new parent entry if the request specified
the new parent.
The
.B reqOld
attribute is only populated if the entry being modified matches the
configured
.B logold
filter and contains attributes in the
.B logoldattr
list.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.11
    NAME 'auditSearch'
    DESC 'Search operation'
    SUP auditReadObject STRUCTURAL
    MUST ( reqScope $ reqDerefAliases $ reqAttrsOnly )
    MAY ( reqFilter $ reqAttr $ reqEntries $ reqSizeLimit $
          reqTimeLimit ) )
.RE
.P
For the
.B Search
class the
.B reqScope
attribute contains the scope of the original search request, using the
values specified for the LDAP URL format. I.e.
.BR base ,
.BR one ,
.BR sub ,
or
.BR subord .
The
.B reqDerefAliases
attribute is one of
.BR never ,
.BR finding ,
.BR searching ,
or
.BR always ,
denoting how aliases will be processed during the search.
The
.B reqAttrsOnly
attribute is a Boolean value showing
.B TRUE 
if only attribute names were requested, or
.B FALSE
if attributes and their values were requested.
The
.B reqFilter
attribute carries the filter used in the search request.
The
.B reqAttr
attribute lists the requested attributes if specific attributes were
requested.
The
.B reqEntries
attribute is the integer count of how many entries were returned by
this search request.
The
.B reqSizeLimit
and
.B reqTimeLimit
attributes indicate what limits were requested on the search operation.

.LP
.RS 4
(  1.3.6.1.4.1.4203.666.11.5.2.12
    NAME 'auditExtended'
    DESC 'Extended operation'
    SUP auditObject STRUCTURAL
    MAY reqData )
.RE
.P
The
.B Extended
class represents an LDAP Extended Operation. As noted above, the actual OID of
the operation is included in the
.B reqType
attribute of the parent class. If any optional data was provided with the
request, it will be contained in the
.B reqData
attribute as an uninterpreted octet string.

.SH NOTES
The Access Log implemented by this overlay may be used for a variety of
other tasks, e.g. as a ChangeLog for a replication mechanism, as well
as for security/audit logging purposes.

.SH FILES
.TP
/etc/openldap/slapd.conf
default slapd configuration file
.SH SEE ALSO
.BR slapd.conf (5),
.BR slapd\-config (5).

.SH ACKNOWLEDGEMENTS
.P
This module was written in 2005 by Howard Chu of Symas Corporation.