NAME¶
ldapx - LDAP extended object interface
SYNOPSIS¶
package require
Tcl 8.4
package require
ldapx ?1.0?
e reset
e dn ?
newdn?
e rdn
e superior
e print
se isempty
se get attr
se get1 attr
se set attr values
se set1 attr value
se add attr values
se add1 attr value
se del attr ?
values?
se del1 attr value
se getattr
se getall
se setall avpairs
se backup ?
other?
se swap
se restore ?
other?
se apply centry
ce change ?
new?
ce diff new ?
old?
la error ?
newmsg?
la connect url ?
binddn? ?
bindpw?
la disconnect
la traverse base filter attrs entry
body
la search base filter attrs
la read base filter entry ...
entry
la commit entry ...
entry
li channel chan
li error ?
newmsg?
li read entry
li write entry
DESCRIPTION¶
The
ldapx package provides an extended Tcl interface to LDAP directores
and LDIF files. The
ldapx package is built upon the
ldap package
in order to get low level LDAP access.
LDAP access is compatible with RFC 2251 (
http://www.rfc-editor.org/rfc/rfc2251.txt). LDIF access is compatible
with RFC 2849 (
http://www.rfc-editor.org/rfc/rfc2849.txt).
OVERVIEW¶
The
ldapx package provides objects to interact with LDAP directories and
LDIF files with an easy to use programming interface. It implements three
snit::type classes.
The first class,
entry, is used to store individual entries. Two
different formats are available: the first one is the
standard format,
which represents an entry as read from the directory. The second format is the
change format, which stores differences between two standard entries.
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.
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.
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.
The second class is the
ldap class. It provides a method to
connect and bind to the directory with a uniform access to LDAP and
LDAPS through an URL (
ldap:// or
ldaps://). The
traverse control
structure executes a body for each entry found in the directory. The
commit method applies some changes (represented as
entry
objects) to the directory. Since some attributes are represented as UTF-8
strings, the option
-utf8 controls which attributes must be converted
and which attributes must not be converted.
The last class is the
ldif class. It provides a method to associate a
standard Tcl
channel to an LDIF object. Then, methods
read and
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
-utf8 works exactly as with the
ldap
class.
ENTRY CLASS¶
ENTRY INSTANCE DATA¶
An instance of the
entry class keeps the following data:
- dn
- This is the DN of the entry, which includes (in LDAP terminology) the RDN
(relative DN) and the Superior parts.
- format
- The format may be uninitialized (entry not yet used),
standard or change. Most methods check the format of the
entry, which can be reset with the reset method.
- attrvals
- In a 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.
- backup
- In a standard entry, the backup may contain a copy of the dn and
all attributes and values. Methods backup and restore
manipulate these data, and method diff may use this backup.
- change
- In a change entry, these data represent the modifications. Such
modifications are handled by specialized methods such as apply or
commit. Detailed format should not be used directly by programs.
Internally, modifications are represented as a list of elements, each
element has one of the following formats (which match the corresponding
LDAP operations):
- [1]
- {add {attr1 {val1...valn} attr2 {...} ...}}
Addition of a new entry.
- [2]
- {mod {modop {attr1 ?val1...valn?} attr2 ...} {modop ...} ...}
Modification of one or more attributes and/or values, where <modop>
can be modadd, moddel or modrepl (see the LDAP modify
operation).
- [3]
- {del}
Deletion of an old entry.
- [4]
- {modrdn newrdn deleteoldrdn ?newsuperior?}
Renaming of an entry.
ENTRY OPTIONS¶
No option is defined by this class.
METHODS FOR ALL KINDS OF ENTRIES¶
- e reset
- This method resets the entry to an uninitialized state.
- e dn ?newdn?
- This method returns the current DN of the entry. If the optional
newdn is specified, it replaces the current DN of the entry.
- e rdn
- This method returns the RDN part of the DN of the entry.
- e superior
- This method returns the superior part of the DN of the entry.
- e print
- This method returns the entry as a string ready to be printed.
METHODS FOR STANDARD ENTRIES ONLY¶
In all methods, attribute names are converted in lower case.
- se isempty
- This method returns 1 if the entry is empty (i.e. without any
attribute).
- se get attr
- This method returns all values of the attribute attr, or the empty
list if the attribute is not fond.
- se get1 attr
- This method returns the first value of the attribute.
- se set attr values
- This method sets the values (list values) of the attribute
attr. If the list is empty, this method deletes all
- se set1 attr value
- This method sets the values of the attribute attr to be an unique
value value. Previous values, if any, are replaced by the new
value.
- se add attr values
- This method adds all elements the list values to the values of the
attribute attr.
- se add1 attr value
- This method adds a single value given by the parameter value to the
attribute attr.
- se del attr ?values?
- If the optional list values is specified, this method deletes all
specified values from the attribute attr. If the argument
values is not specified, this method deletes all values.
- se del1 attr value
- This method deletes a unique value from the attribute
attr.
- se getattr
- This method returns all attributes names.
- se getall
- This method returns all attributes and values from the entry, packed in a
list of pairs <attribute, list of values>.
- se setall avpairs
- This method sets at once all attributes and values. The format of the
avpairs argument is the same as the one returned by method
getall.
- se backup ?other?
- This method stores in an other standard entry object a copy of the
current DN and attributes/values. If the optional other argument is
not specified, copy is done in the current entry (in a specific place, see
section OVERVIEW).
- se swap
- This method swaps the current and backup contexts of the entry.
- se restore ?other?
- If the optional argument other is given, which must then be a
standard entry, this method restores the current entry into the
other entry. If the argument other argument is not
specified, this methods restores the current entry from its internal
backup (see section OVERVIEW).
- se apply centry
- This method applies changes defined in the centry argument, which
must be a change entry.
METHODS FOR CHANGE ENTRIES ONLY¶
- ce change ?new?
- If the optional argument new is specified, this method modifies the
change list (see subsection 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
apply or commit.
- ce diff new ?old?
- This method computes the differences between the new and old
entries under the form of a change list, and stores this list into the
current change entry. If the optional argument old is not
specified, difference is computed from the entry and its internal backup
(see section OVERVIEW). Return value is the computed change
list.
ENTRY 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
LDAP CLASS¶
LDAP INSTANCE DATA¶
An instance of the
ldap class keeps the following data:
- channel
- This is the channel used by the ldap package for communication with
the LDAP server.
- lastError
- This variable contains the error message which appeared in the last method
of the ldap class (this string is modified in nearly all methods).
The error method may be used to fetch this message.
LDAP OPTIONS¶
A first set of options of the
ldap class is used during search operations
(methods
traverse,
search and
read, see below).
- -scope base|one|sub
- Specify the scope of the LDAP search to be one of base, one
or sub to specify a base object, one-level or subtree search.
The default is sub.
- -derefaliases
never|seach|find|always
- Specify how aliases dereferencing is handled: never is used to
specify that aliases are never derefenced, always that aliases are
always derefenced, search that aliases are dereferenced when
searching, or find that aliases are dereferenced only when locating
the base object for the search.
The default is never.
- -sizelimit integer
- Specify the maximum number of entries to be retreived during a search. A
value of 0 means no limit.
Default is 0.
- -timelimit integer
- Specify the time limit for a search to complete. A value of 0 means
no limit.
Default is 0.
- -attrsonly 0|1
- Specify if only attribute names are to be retrieved (value 1).
Normally (value 0), attribute values are also retrieved.
Default is 0.
The last option is used when getting entries or committing changes in the
directory:
- -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 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.
Default is {{.*} {}}, meaning: all attributes are converted, without
exception.
LDAP METHODS¶
- la error ?newmsg?
- This method returns the error message that occurred in the last call to a
ldap class method. If the optional argument newmsg is
supplied, it becomes the last error message.
- la connect url ?binddn? ?bindpw?
- This method connects to the LDAP server using given URL (which can be of
the form ldap://host:port or ldaps://host:port). If an
optional binddn argument is given together with the bindpw
argument, the connect binds to the LDAP server using the specified
DN and password.
- la disconnect
- This method disconnects (and unbinds, if necessary) from the LDAP
server.
- la traverse base filter attrs
entry body
- This method is a new control structure. It searches the LDAP directory
from the specified base DN (given by the base argument) and selects
entries based on the argument filter. For each entry found, this
method fetches attributes specified by the attrs argument (or all
attributes if it is an empty list), stores them in the entry
instance of class entry and executes the script defined by the
argument body. Options are used to refine the search.
Caution: when this method is used, the script body cannot perform
another LDAP search (methods traverse, search or
read).
- la search base filter attrs
- This method searches the directory using the same way as method
traverse. All found entries are stored in newly created instances
of class entry, which are returned in a list. The newly created
instances should be destroyed when they are no longer used.
- la read base filter entry ...
entry
- This method reads one or more entries, using the same search criteria as
methods traverse and 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 entry
argument, this method just returns the number of entries found, without
returning any data.
- la commit entry ... entry
- This method commits the changes stored in the entry arguments. Each
entry may be either a change entry, or a standard
entry with a backup.
Note: in the future, this method should use the LDAP transaction extension
provided by OpenLDAP 2.3 and later.
LDAP EXAMPLE¶
package require ldapx
#
# Connects to the LDAP directory
#
::ldapx::ldap create l
set url "ldap://server.mycomp.com"
if {! [l connect $url "cn=admin,o=mycomp" "mypasswd"]} then {
puts stderr "error: [l error]"
exit 1
}
#
# Search all entries matching some criterion
#
l configure -scope one
::ldapx::ldap create e
set n 0
l traverse "ou=people,o=mycomp" "(sn=Joe*)" {sn givenName} e {
puts "dn: [e dn]"
puts " sn: [e get1 sn]"
puts " givenName: [e get1 givenName]"
incr n
}
puts "$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::ldap 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
LDIF CLASS¶
LDIF INSTANCE DATA¶
An instance of the
ldif class keeps the following data:
- 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
channel. There is no need to disrupt this association when the LDIF
file operation has ended.
- format
- LDIF files may contain standard entries or 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).
- lastError
- This variable contains the error message which appeared in the last method
of the ldif class (this string is modified in nearly all methods).
The error method may be used to fetch this message.
- version
- This is the version of the LDIF file. Only version 1 is supported: the
method read can only read from version 1 files, and method
write only creates version 1 files.
LDIF OPTIONS¶
This class defines two options:
- -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
replica and time attributes since they do not conform to the
RFC 2849 standard for LDIF files.
Default is empty list: no attribute is ignored.
- -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 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.
Default is {{.*} {}}, meaning: all attributes are converted, without
exception.
LDIF METHODS¶
- li channel chan
- This method associates the Tcl channel named chan with the LDIF
instance. It resets the type of LDIF object to uninitialized.
- li error ?newmsg?
- This method returns the error message that occurred in the last call to a
ldif class method. If the optional argument newmsg is
supplied, it becomes the last error message.
- li read entry
- This method reads the next entry from the LDIF file and stores it in the
entry object of class entry. The entry may be a
standard or change entry.
- li write entry
- This method writes the entry given in the argument entry to the
LDIF file.
LDIF 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
REFERENCES¶
BUGS, IDEAS, FEEDBACK¶
This document, and the package it describes, will undoubtedly contain bugs and
other problems. Please report such in the category
ldap of the
Tcllib Trackers [
http://core.tcl.tk/tcllib/reportlist]. Please also
report any ideas for enhancements you may have for either package and/or
documentation.
KEYWORDS¶
directory access, internet, ldap, ldap client, ldif, protocol, rfc 2251, rfc
2849
CATEGORY¶
Networking
COPYRIGHT¶
Copyright (c) 2006 Pierre David <pdav@users.sourceforge.net>