path: root/tcllib/modules/ldap/ldapx.man

[comment {-*- tcl -*- doctools manpage}]
[comment {$Id: ldapx.man,v 1.14 2009/01/29 06:16:19 andreas_kupries Exp $}]
[manpage_begin ldapx n 0.2.5]
[keywords {directory access}]
[keywords internet]
[keywords ldap]
[keywords {ldap client}]
[keywords ldif]
[keywords protocol]
[keywords {rfc 2251}]
[keywords {rfc 2849}]
[copyright {2006 Pierre David <pdav@users.sourceforge.net>}]
[moddesc   {LDAP extended object interface}]
[titledesc {LDAP extended object interface}]
[category  Networking]
[require Tcl 8.4]
[require ldapx [opt 1.0]]
[description]
[para]

The [package ldapx] package provides an extended Tcl interface to
LDAP directores and LDIF files. The [package ldapx] package is built
upon the [package ldap] package in order to get low level LDAP access.

[para]

LDAP access is compatible with RFC 2251
([uri http://www.rfc-editor.org/rfc/rfc2251.txt]).
LDIF access is compatible with RFC 2849
([uri http://www.rfc-editor.org/rfc/rfc2849.txt]).

[section OVERVIEW]

The [package ldapx] package provides objects to interact with LDAP
directories and LDIF files with an easy to use programming interface.
It implements three [package snit]::type classes.

[para]

The first class, [class entry], is used to store individual entries.
Two different formats are available: the first one is the
[emph standard] format, which represents an entry as read from the
directory. The second format is the [emph change] format, which
stores differences between two standard entries.

[para]

With these entries, an application which wants to modify an entry
in a directory needs to read a (standard) entry from the directory,
create a fresh copy into a new (standard) entry, modify the new
copy, and then compute the differences between the two entries into
a new (change) entry, which may be commited to the directory.

[para]

Such kinds of modifications are so heavily used that standard entries
may contain their own copy of the original data. With such a copy,
the application described above reads a (standard) entry from the
directory, backs-up the original data, modifies the entry, and
computes the differences between the entry and its backup. These
differences are then commited to the directory.

[para]

Methods are provided to compute differences between two entries,
to apply differences to an entry in order to get a new entry, and
to get or set attributes in standard entries.

[para]

The second class is the [class ldap] class. It provides a method
to [method connect] and bind to the directory with a uniform access
to LDAP and LDAPS through an URL (ldap:// or ldaps://). The
[method traverse] control structure executes a body for each entry
found in the directory. The [method commit] method applies some
changes (represented as [class entry] objects) to the directory.
Since some attributes are represented as UTF-8 strings, the option
[option -utf8] controls which attributes must be converted and
which attributes must not be converted.

[para]

The last class is the [class ldif] class. It provides a method to
associate a standard Tcl [emph channel] to an LDIF object. Then,
methods [method read] and [method write] read or write entries from
or to this channel. This class can make use of standard or change
entries, according to the type of the LDIF file which may contain
either standard entries or change entries (but not both at the same
time). The option [option -utf8] works exactly as with the
[class ldap] class.

[section {ENTRY CLASS}]

[subsection {Entry Instance Data}]

An instance of the [class entry] class keeps the following data:

[list_begin definitions]

    [def dn]

	This is the DN of the entry, which includes (in LDAP
	terminology) the RDN (relative DN) and the Superior parts.

    [def format]

	The format may be [emph uninitialized] (entry not yet used),
	[emph standard] or [emph change]. Most methods check the
	format of the entry, which can be reset with the
	[method reset] method.

    [def attrvals]

	In a [emph standard] entry, this is where the attributes
	and associated values are stored. Many methods provide
	access to these informations. Attribute names are always
	converted into lower case.

    [def backup]

	In a [emph standard] entry, the backup may contain a copy
	of the dn and all attributes and values. Methods
	[method backup] and [method restore] manipulate these data,
	and method [method diff] may use this backup.

    [def change]

	In a [emph change] entry, these data represent the
	modifications. Such modifications are handled by specialized
	methods such as [method apply] or [method commit].
	Detailed format should not be used directly by programs.
	[para]
	Internally, modifications are represented as a list of
	elements, each element has one of the following formats
	(which match the corresponding LDAP operations):

	[list_begin enumerated]

	    [enum]
		{[const add] {attr1 {val1...valn} attr2 {...} ...}}
		[para]
		Addition of a new entry.

	    [enum]
		{[const mod] {modop {attr1 [opt val1...valn]} attr2 ...} {modop ...} ...}
		[para]
		Modification of one or more attributes and/or values,
		where <modop> can be [const modadd], [const moddel]
		or [const modrepl] (see the LDAP modify operation).

	    [enum]
		{[const del]}
		[para]
		Deletion of an old entry.

	    [enum]
		{[const modrdn] newrdn deleteoldrdn [opt newsuperior]}
		[para]
		Renaming of an entry.

	[list_end]

[list_end]

[subsection {Entry Options}]

No option is defined by this class.

[subsection {Methods for all kinds of entries}]

[list_begin definitions]
    [call [arg e] [method reset]]

	This method resets the entry to an uninitialized state.

    [call [arg e] [method dn] [opt [arg newdn]]]

	This method returns the current DN of the entry. If the
	optional [arg newdn] is specified, it replaces the current
	DN of the entry.

    [call [arg e] [method rdn]]

	This method returns the RDN part of the DN of the entry.

    [call [arg e] [method superior]]

	This method returns the superior part of the DN of the entry.

    [call [arg e] [method print]]

	This method returns the entry as a string ready to be printed.

[list_end]

[para]

[subsection {Methods for standard entries only}]

In all methods, attribute names are converted in lower case.

[list_begin definitions]
    [call [arg se] [method isempty]]

	This method returns 1 if the entry is empty (i.e. without
	any attribute).

    [call [arg se] [method get] [arg attr]]

	This method returns all values of the attribute [arg attr],
	or the empty list if the attribute is not fond.

    [call [arg se] [method get1] [arg attr]]

	This method returns the first value of the attribute.

    [call [arg se] [method set] [arg attr] [arg values]]

	This method sets the values (list [arg values]) of the
	attribute [arg attr]. If the list is empty, this method
	deletes all

    [call [arg se] [method set1] [arg attr] [arg value]]

	This method sets the values of the attribute [arg attr] to
	be an unique value [arg value]. Previous values, if any,
	are replaced by the new value.

    [call [arg se] [method add] [arg attr] [arg values]]

	This method adds all elements the list [arg values] to the
	values of the attribute [arg attr].

    [call [arg se] [method add1] [arg attr] [arg value]]

	This method adds a single value given by the parameter
	[arg value] to the attribute [arg attr].

    [call [arg se] [method del] [arg attr] [opt [arg values]]]

	If the optional list [arg values] is specified, this method
	deletes all specified values from the attribute [arg attr].
	If the argument [arg values] is not specified, this method
	deletes all values.

    [call [arg se] [method del1] [arg attr] [arg value]]

	This method deletes a unique [arg value] from the attribute
	[arg attr].

    [call [arg se] [method getattr]]

	This method returns all attributes names.

    [call [arg se] [method getall]]

	This method returns all attributes and values from the
	entry, packed in a list of pairs <attribute, list of values>.

    [call [arg se] [method setall] [arg avpairs]]

	This method sets at once all attributes and values. The
	format of the [arg avpairs] argument is the same as the one
	returned by method [method getall].

    [call [arg se] [method backup] [opt [arg other]]]

	This method stores in an [arg other] standard entry object
	a copy of the current DN and attributes/values. If the
	optional [arg other] argument is not specified, copy is
	done in the current entry (in a specific place, see section
	[sectref OVERVIEW]).

    [call [arg se] [method swap]]

	This method swaps the current and backup contexts of the
	entry.

    [call [arg se] [method restore] [opt [arg other]]]

	If the optional argument [arg other] is given, which must
	then be a [emph standard] entry, this method restores the
	current entry into the [arg other] entry. If the argument
	[arg other] argument is not specified, this methods restores
	the current entry from its internal backup (see section
	[sectref OVERVIEW]).

    [call [arg se] [method apply] [arg centry]]

	This method applies changes defined in the [arg centry]
	argument, which must be a [emph change] entry.

[list_end]

[subsection {Methods for change entries only}]

[list_begin definitions]
    [call [arg ce] [method change] [opt [arg new]]]

	If the optional argument [arg new] is specified, this method
	modifies the change list (see subsection [sectref {Entry Instance Data}] for
	the exact format). In both cases, current change list is
	returned.
	Warning: values returned by this method should only be used
	by specialized methods such as [method apply] or
	[method commit].

    [call [arg ce] [method diff] [arg new] [opt [arg old]]]

	This method computes the differences between the [arg new]
	and [arg old] entries under the form of a change list, and
	stores this list into the current [emph change] entry. If
	the optional argument [arg old] is not specified, difference
	is computed from the entry and its internal backup (see
	section [sectref OVERVIEW]). Return value is the computed
	change list.

[list_end]

[subsection {Entry Example}]

[example {
    package require ldapx

    #
    # Create an entry and fill it as a standard entry with
    # attributes and values
    #
    ::ldapx::entry create e
    e dn "uid=joe,ou=people,o=mycomp"
    e set1 "uid"             "joe"
    e set  "objectClass"     {person anotherObjectClass}
    e set1 "givenName"       "Joe"
    e set1 "sn"              "User"
    e set  "telephoneNumber" {+31415926535 +2182818}
    e set1 "anotherAttr"     "This is a beautiful day, isn't it?"

    puts stdout "e\n[e print]"

    #
    # Create a second entry as a backup of the first, and
    # make some changes on it.
    # Entry is named automatically by snit.
    #

    set b [::ldapx::entry create %AUTO%]
    e backup $b

    puts stdout "$b\n[$b print]"

    $b del  "anotherAttr"
    $b del1 "objectClass" "anotherObjectClass"

    #
    # Create a change entry, a compute differences between first
    # and second entry.
    #

    ::ldapx::entry create c
    c diff e $b

    puts stdout "$c\n[$c print]"

    #
    # Apply changes to first entry. It should be the same as the
    # second entry, now.
    #

    e apply c

    ::ldapx::entry create nc
    nc diff e $b

    puts stdout "nc\n[nc print]"

    #
    # Clean-up
    #

    e destroy
    $b destroy
    c destroy
    nc destroy
}]

[section {LDAP CLASS}]

[subsection {Ldap Instance Data}]

An instance of the [class ldap] class keeps the following data:

[list_begin definitions]

    [def channel]

	This is the channel used by the [package ldap] package for
	communication with the LDAP server.

    [def lastError]

	This variable contains the error message which appeared in
	the last method of the [class ldap] class (this string is
	modified in nearly all methods). The [method error] method
	may be used to fetch this message.

[list_end]

[subsection {Ldap Options}]

A first set of options of the [class ldap] class is used during
search operations (methods [method traverse], [method search] and
[method read], see below).

[list_begin options]

    [opt_def -scope [const base]|[const one]|[const sub]]

	Specify the scope of the LDAP search to be one of
	[const base], [const one] or [const sub] to specify
	a base object, one-level or subtree search.
	[para]
	The default is [const sub].

    [opt_def -derefaliases [const never]|[const seach]|[const find]|[const always]]

	Specify how aliases dereferencing is handled:
	[const never] is used to specify that aliases are never derefenced,
	[const always] that aliases are always derefenced,
	[const search] that aliases are dereferenced when searching,
	or [const find] that aliases are dereferenced only  when
	locating  the  base object for the search.
	[para]
	The default is [const never].

    [opt_def -sizelimit integer]

	Specify the maximum number of entries to be retreived
	during a search. A value of [const 0] means no limit.
	[para]
	Default is [const 0].

    [opt_def -timelimit integer]

	Specify the time limit for a search to complete.
	A value of [const 0] means no limit.
	[para]
	Default is [const 0].

    [opt_def -attrsonly [const 0]|[const 1]]

	Specify if only attribute names are to be retrieved (value
	[const 1]). Normally (value [const 0]), attribute values
	are also retrieved.
	[para]
	Default is [const 0].

[list_end]

[para]

The last option is used when getting entries or committing changes
in the directory:

[list_begin options]

    [opt_def -utf8 {pattern-yes pattern-no}]

	Specify which attribute values are encoded in UTF-8. This
	information is specific to the LDAP schema in use by the
	application, since some attributes such as jpegPhoto, for
	example, are not encoded in UTF-8. This option takes the
	form of a list with two regular expressions suitable for
	the [cmd regexp] command (anchored by ^ and $).
	The first specifies which attribute names are to be UTF-8
	encoded, and the second selects, among those, the attribute
	names which will not be UTF-8 encoded.  It is thus possible
	to say: convert all attributes, except jpegPhoto.

	[para]

	Default is {{.*} {}}, meaning: all attributes are converted,
	without exception.

[list_end]

[subsection {Ldap Methods}]

[list_begin definitions]
    [call [arg la] [method error] [opt [arg newmsg]]]

	This method returns the error message that occurred in the
	last call to a [class ldap] class method. If the optional
	argument [arg newmsg] is supplied, it becomes the last
	error message.

    [call [arg la] [method connect] [arg url] [opt [arg binddn]] [opt [arg bindpw]]]

	This method connects to the LDAP server using given URL
	(which can be of the form [uri ldap://host:port] or
	[uri ldaps://host:port]). If an optional [arg binddn]
	argument is given together with the [arg bindpw] argument,
	the [method connect] binds to the LDAP server using the
	specified DN and password.

    [call [arg la] [method disconnect]]

	This method disconnects (and unbinds, if necessary) from
	the LDAP server.

    [call [arg la] [method traverse] [arg base] [arg filter] [arg attrs] [arg entry] [arg body]]

	This method is a new control structure. It searches the
	LDAP directory from the specified base DN (given by the
	[arg base] argument) and selects entries based on the
	argument [arg filter]. For each entry found, this method
	fetches attributes specified by the [arg attrs] argument
	(or all attributes if it is an empty list), stores them in
	the [arg entry] instance of class [class entry] and executes
	the script defined by the argument [arg body]. Options are
	used to refine the search.

	[para]

	Caution: when this method is used, the script [arg body]
	cannot perform another LDAP search (methods [method traverse],
	[method search] or [method read]).

    [call [arg la] [method search] [arg base] [arg filter] [arg attrs]]

	This method searches the directory using the same way as
	method [method traverse]. All found entries are stored in
	newly created instances of class [class entry], which are
	returned in a list. The newly created instances should be
	destroyed when they are no longer used.

    [call [arg la] [method read] [arg base] [arg filter] [arg entry] ... [arg entry]]

	This method reads one or more entries, using the same search
	criteria as methods [method traverse] and [method search].
	All attributes are stored in the entries. This method
	provides a quick way to read some entries. It returns the
	number of entries found in the directory (which may be more
	than the number of read entries). If called without any
	[arg entry] argument, this method just returns the number
	of entries found, without returning any data.

    [call [arg la] [method commit] [arg entry] ... [arg entry]]

	This method commits the changes stored in the [arg entry]
	arguments. Each [arg entry] may be either a [emph change]
	entry, or a [emph standard] entry with a backup.
	[para]
	Note: in the future, this method should use the LDAP
	transaction extension provided by OpenLDAP 2.3 and later.

[list_end]

[subsection {Ldap Example}]

[example {
    package require ldapx

    #
    # Connects to the LDAP directory
    #

    ::ldapx::ldap create l
    set url "ldap://server.mycomp.com"
    if {! [l connect $url "cn=admin,o=mycomp" "mypasswd"]} then {
	puts stderr "error: [l error]"
	exit 1
    }

    #
    # Search all entries matching some criterion
    #

    l configure -scope one
    ::ldapx::entry create e
    set n 0
    l traverse "ou=people,o=mycomp" "(sn=Joe*)" {sn givenName} e {
	puts "dn: [e dn]"
	puts "  sn:        [e get1 sn]"
	puts "  givenName: [e get1 givenName]"
	incr n
    }
    puts "$n entries found"
    e destroy

    #
    # Add a telephone number to some entries
    # Note this modification cannot be done in the "traverse" operation.
    #

    set lent [l search "ou=people,o=mycomp" "(sn=Joe*)" {}]
    ::ldapx::entry create c
    foreach e $lent {
	$e backup
	$e add1 "telephoneNumber" "+31415926535"
	c diff $e
	if {! [l commit c]} then {
	    puts stderr "error: [l error]"
	    exit 1
	}
	$e destroy
    }

    l disconnect
    l destroy
}]

[section {LDIF CLASS}]

[subsection {Ldif Instance Data}]

An instance of the [class ldif] class keeps the following data:

[list_begin definitions]

    [def channel]

	This is the Tcl channel used to retrieve or store LDIF file
	contents. The association between an instance and a channel
	is made by the method [method channel]. There is no need
	to disrupt this association when the LDIF file operation
	has ended.

    [def format]

	LDIF files may contain [emph standard] entries or
	[emph change] entries, but not both. This variable contains
	the detected format of the file (when reading) or the format
	of entries written to the file (when writing).

    [def lastError]

	This variable contains the error message which appeared in
	the last method of the [class ldif] class (this string is
	modified in nearly all methods). The [method error] method
	may be used to fetch this message.

    [def version]

	This is the version of the LDIF file. Only version 1 is
	supported: the method [method read] can only read from
	version 1 files, and method [method write] only creates
	version 1 files.

[list_end]

[subsection {Ldif Options}]

This class defines two options:

[list_begin options]

    [opt_def -ignore {list-of-attributes}]

	This option is used to ignore certain attribute names on
	reading. For example, to read OpenLDAP replica files (replog),
	one must ignore [const replica] and [const time] attributes
	since they do not conform to the RFC 2849 standard for LDIF
	files.
	[para]
	Default is empty list: no attribute is ignored.

    [opt_def -utf8 {pattern-yes pattern-no}]

	Specify which attribute values are encoded in UTF-8. This
	information is specific to the LDAP schema in use by the
	application, since some attributes such as jpegPhoto, for
	example, are not encoded in UTF-8. This option takes the
	form of a list with two regular expressions suitable for
	the [cmd regexp] command (anchored by ^ and $).
	The first specifies which attribute names are to be UTF-8
	encoded, and the second selects, among those, the attribute
	names which will not be UTF-8 encoded.  It is thus possible
	to say: convert all attributes, except jpegPhoto.

	[para]

	Default is {{.*} {}}, meaning: all attributes are converted,
	without exception.

[list_end]

[subsection {Ldif Methods}]

[list_begin definitions]

    [call [arg li] [method channel] [arg chan]]

	This method associates the Tcl channel named [arg chan]
	with the LDIF instance. It resets the type of LDIF object
	to [emph uninitialized].

    [call [arg li] [method error] [opt [arg newmsg]]]

	This method returns the error message that occurred in the
	last call to a [class ldif] class method. If the optional
	argument [arg newmsg] is supplied, it becomes the last
	error message.

    [call [arg li] [method read] [arg entry]]

	This method reads the next entry from the LDIF file and
	stores it in the [arg entry] object of class [class entry].
	The entry may be a [emph standard] or [emph change] entry.

    [call [arg li] [method write] [arg entry]]

	This method writes the entry given in the argument
	[arg entry] to the LDIF file.

[list_end]

[subsection {Ldif Example}]

[example {
    package require ldapx

    # This examples reads a LDIF file containing entries,
    # compare them to a LDAP directory, and writes on standard
    # output an LDIF file containing changes to apply to the
    # LDAP directory to match exactly the LDIF file.

    ::ldapx::ldif create liin
    liin channel stdin

    ::ldapx::ldif create liout
    liout channel stdout

    ::ldapx::ldap create la
    if {! [la connect "ldap://server.mycomp.com"]} then {
	puts stderr "error: [la error]"
	exit 1
    }
    la configure -scope one

    # Reads LDIF file

    ::ldapx::entry create e1
    ::ldapx::entry create e2
    ::ldapx::entry create c

    while {[liin read e1] != 0} {
	set base [e1 superior]
	set id [e1 rdn]
	if {[la read $base "($id)" e2] == 0} then {
	    e2 reset
	}

	c diff e1 e2
	if {[llength [c change]] != 0} then {
	    liout write c
	}
    }

    la disconnect
    la destroy
    e1 destroy
    e2 destroy
    c destroy
    liout destroy
    liin destroy
}]

[section References]

[vset CATEGORY ldap]
[include ../doctools2base/include/feedback.inc]
[manpage_end]