xref: /netbsd-src/external/bsd/openldap/dist/doc/drafts/draft-sermersheim-ldap-distproc-xx.txt (revision 2de962bd804263c16657f586aa00f1704045df8e)
1
2Network Working Group                                     J. Sermersheim
3Internet-Draft                                               Novell, Inc
4Expires: August 26, 2005                               February 22, 2005
5
6
7
8               Distributed Procedures for LDAP Operations
9                 draft-sermersheim-ldap-distproc-02.txt
10
11
12Status of this Memo
13
14
15   This document is an Internet-Draft and is subject to all provisions
16   of Section 3 of RFC 3667.  By submitting this Internet-Draft, each
17   author represents that any applicable patent or other IPR claims of
18   which he or she is aware have been or will be disclosed, and any of
19   which he or she become aware will be disclosed, in accordance with
20   RFC 3668.
21
22
23   Internet-Drafts are working documents of the Internet Engineering
24   Task Force (IETF), its areas, and its working groups.  Note that
25   other groups may also distribute working documents as
26   Internet-Drafts.
27
28
29   Internet-Drafts are draft documents valid for a maximum of six months
30   and may be updated, replaced, or obsoleted by other documents at any
31   time.  It is inappropriate to use Internet-Drafts as reference
32   material or to cite them other than as "work in progress."
33
34
35   The list of current Internet-Drafts can be accessed at
36   http://www.ietf.org/ietf/1id-abstracts.txt.
37
38
39   The list of Internet-Draft Shadow Directories can be accessed at
40   http://www.ietf.org/shadow.html.
41
42
43   This Internet-Draft will expire on August 26, 2005.
44
45
46Copyright Notice
47
48
49   Copyright (C) The Internet Society (2005).
50
51
52Abstract
53
54
55   This document provides the data types and procedures used while
56   servicing Lightweight Directory Access Protocol (LDAP) user
57   operations in order to participate in a distributed directory.  In
58   particular, it describes the way in which an LDAP user operation in a
59   distributed directory environment finds its way to the proper DSA(s)
60   for servicing.
61
62
63
64
65
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69
70
71Discussion Forum
72
73
74   Technical discussion of this document will take place on the IETF
75   LDAP Extensions mailing list <ldapext@ietf.org>.  Please send
76   editorial comments directly to the author.
77
78
79Table of Contents
80
81
82   1.   Distributed Operations Overview  . . . . . . . . . . . . . .   3
83   2.   Conventions  . . . . . . . . . . . . . . . . . . . . . . . .   4
84   3.   Distributed Operation Data Types . . . . . . . . . . . . . .   5
85   3.1  ContinuationReference  . . . . . . . . . . . . . . . . . . .   5
86   3.2  ChainedRequest . . . . . . . . . . . . . . . . . . . . . . .   9
87   3.3  Chained Response . . . . . . . . . . . . . . . . . . . . . .  11
88   4.   Distributed Procedures . . . . . . . . . . . . . . . . . . .  14
89   4.1  Name resolution  . . . . . . . . . . . . . . . . . . . . . .  14
90   4.2  Operation Evaluation . . . . . . . . . . . . . . . . . . . .  16
91   4.3  Populating the ContinuationReference . . . . . . . . . . . .  19
92   4.4  Sending a ChainedRequest . . . . . . . . . . . . . . . . . .  21
93   4.5  Emulating the Sending of a ChainedRequest  . . . . . . . . .  23
94   4.6  Receiving a ChainedRequest . . . . . . . . . . . . . . . . .  24
95   4.7  Returning a Chained Response . . . . . . . . . . . . . . . .  25
96   4.8  Receiving a Chained Response . . . . . . . . . . . . . . . .  26
97   4.9  Returning a Referral or Intermediate Referral  . . . . . . .  27
98   4.10 Acting on a Referral or Intermediate Referral  . . . . . . .  30
99   4.11 Ensuring non-existence of an entry under an nssr . . . . . .  31
100   4.12 Mapping a referralURI to an LDAP URI . . . . . . . . . . . .  31
101   4.13 Using the ManageDsaIT control  . . . . . . . . . . . . . . .  32
102   5.   Security Considerations  . . . . . . . . . . . . . . . . . .  33
103   6.   Normative References . . . . . . . . . . . . . . . . . . . .  33
104        Author's Address . . . . . . . . . . . . . . . . . . . . . .  34
105   A.   IANA Considerations  . . . . . . . . . . . . . . . . . . . .  35
106   A.1  LDAP Object Identifier Registrations . . . . . . . . . . . .  35
107   A.2  LDAP Protocol Mechanism Registrations  . . . . . . . . . . .  35
108   A.3  LDAP Descriptor Registrations  . . . . . . . . . . . . . . .  37
109   A.4  LDAP Result Code Registrations . . . . . . . . . . . . . . .  38
110        Intellectual Property and Copyright Statements . . . . . . .  39
111
112
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122
123
124
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129
130
1311.  Distributed Operations Overview
132
133
134   One characteristic of X.500-based directory systems [X500] is that,
135   given a distributed Directory Information Tree (DIT), a user should
136   potentially be able to have any service request satisfied (subject to
137   security, access control, and administrative policies) irrespective
138   of the Directory Service Agent (DSA) to which the request was sent.
139   To accommodate this requirement, it is necessary that any DSA
140   involved in satisfying a particular service request have some
141   knowledge (as specified in {TODO: Link to future Distributed Data
142   Model doc}) of where the requested information is located and either
143   return this knowledge to the requester or attempt to satisfy the
144   request satisfied on the behalf of the requester (the requester may
145   either be a Directory User Agent (DUA) or another DSA).
146
147
148   Two modes of operation distribution are defined to meet these
149   requirements, namely "chaining" and "returning referrals".
150   "Chaining" refers to the attempt by a DSA to satisfy a request by
151   sending one or more chained operations to other DSAs.  "Returning
152   referrals", is the act of returning distributed knowledge information
153   to the requester, which may then itself interact with the DSA(s)
154   identified by the distributed knowledge information.  It is a goal of
155   this document to provide the same level of service whether the
156   chaining or referral mechanism is used to distribute an operation.
157
158
159   The processing of an operation is talked about in two major phases,
160   namely "name resolution", and "operation evaluation".  Name
161   resolution is the act of locating a local DSE held on a DSA given a
162   distinguished name (DN).  Operation evaluation is the act of
163   performing the operation after the name resolution phase is complete.
164
165
166   While distributing an operation, a request operation may be
167   decomposed into several sub-operations.
168
169
170   The distributed directory operation procedures described in this
171   document assume the absense of the ManageDsaIT control defined in
172   [RFC3296] and described in Section 4.13.
173
174
175
176
177
178
179
180
181
182
183
184
185
186
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191
192
1932.  Conventions
194
195
196   Imperative keywords defined in [RFC2119] are used in this document,
197   and carry the meanings described there.
198
199
200   All Basic Encoding Rules (BER) [X690] encodings follow the
201   conventions found in Section 5.1 of [RFC2251].
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
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225
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250
251
2523.  Distributed Operation Data Types
253
254
255   The data types in this section are used by the chaining and referral
256   distributed operation mechanisms described in Section 4
257
258
2593.1  ContinuationReference
260
261
262   As an operation is being processed by a DSA, it is useful to group
263   the information passed between various procedures as a collection of
264   data.  The ContinuationReference data type is introduced for this
265   purpose.  This data type is populated and consumed by various
266   procedures discussed in various sections of this document.  In
267   general, a ContinuationReference is used when indicating that
268   directory information being acted on is not present locally, but may
269   be present elsewhere.
270
271
272   A ContinuationReference consists of one or more addresses which
273   identify remote DSAs along with other information pertaining both to
274   the distributed knowledge information held on the local DSA as well
275   as information relevant to the operation.  This data type is
276   expressed here in Abstract Syntax Notation One (ASN.1) [X680].
277
278
279      ContinuationReference ::= SET {
280         referralURI      [0] SET SIZE (1..MAX) OF URI,
281         localReference   [2] LDAPDN,
282         referenceType    [3] ReferenceType,
283         remainingName    [4] RelativeLDAPDN OPTIONAL,
284         searchScope      [5] SearchScope OPTIONAL,
285         searchedSubtrees [6] SearchedSubtrees OPTIONAL,
286         failedName       [7] LDAPDN OPTIONAL,
287         ...  }
288
289
290   <Editor's Note: Planned for addition is a searchCriteria field which
291   is used both for assuring that the remote object is in fact the
292   object originally pointed to (this mechanism provides a security
293   measure), and also to allow moved or renamed remote entries to be
294   found.  Typically the search criteria would have a filter value of
295   (entryUUID=<something>)>
296
297
298   URI ::= LDAPString     -- limited to characters permitted in URIs
299   [RFC2396].
300
301
302      ReferenceType ::= ENUMERATED {
303         superior               (0),
304         subordinate            (1),
305         cross                  (2),
306         nonSpecificSubordinate (3),
307
308
309
310
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315
316
317         suplier                (4),
318         master                 (5),
319         immediateSuperior      (6),
320         self                   (7),
321         ...  }
322      SearchScope ::= ENUMERATED {
323         baseObject         (0),
324         singleLevel        (1),
325         wholeSubtree       (2),
326         subordinateSubtree (3),
327         ...  }
328
329
330   SearchedSubtrees ::= SET OF RelativeLDAPDN
331
332
333   LDAPDN, RelativeLDAPDN, and LDAPString, are defined in [RFC2251].
334
335
336   The following subsections introduce the fields of the
337   ContinuationReference data type, but do not provide in-depth
338   semantics or instructions on the population and consumption of the
339   fields.  These topics are discussed as part of the procedural
340   instructions.
341
342
3433.1.1  ContinuationReference.referralURI
344
345
346   The list of referralURI values is used by the receiver to progress
347   the operation.  Each value specifies (at minimum) the protocol and
348   address of one or more remote DSA(s) holding the data sought after.
349   URI values which are placed in ContinuationReference.referralURI must
350   allow for certain elements of data to be conveyed.  Section 3.1.1.1
351   describes these data elements.  Furthermore, a mapping must exist
352   which relates the parts of a specified URI to these data elements.
353   This document provides such a mapping for the LDAP URL [RFC2255] in
354   Section 4.12.
355
356
357   In some cases, a referralURI will contain data which has a
358   counterpart in the fields of the ContinuationReference (an example is
359   where the referralURI is an LDAP URL, holds a <scope> value, and the
360   ContinuationReference.searchScope field is also present).  In these
361   cases, the data held on the referralURI overrides the field in the
362   ContinuationReference.  Specific examples of this are highlighted in
363   other sections.  Providing a means for these values to exist as
364   fields of the ContinuationReference allows one value to be applied to
365   all values of referralURI (as opposed to populating duplicate data on
366   all referralURI values).
367
368
369   If a referralURI value identifies an LDAP-enabled DSA [RFC3377], the
370   LDAP URL form is used.
371
372
373
374
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379
380
3813.1.1.1  Elements of referralURI Values
382
383
384   The following data elements must be allowed and identified for a
385   specified URI type to be used to convey referral information.  Each
386   element is given a name which begins with 'referralURI.' for clarity
387   when referencing the elements conceptually in other parts of this
388   document.
389
390
391   o  referralURI.protocolIdentifier.  There must be an indication of
392      the protocol to be used to contact the DSA identified by the URI.
393   o  referralURI.accessPoint.  The URI must identify a DSA in a manner
394      that can be used to contact it using the protocol specified in
395      protocolIdentifier.
396   o  referralURI.targetObject.  Holds the name to be used as the base
397      DN of the operation being progressed.  This field must be allowed
398      by the URI specification, but may be omitted in URI instances for
399      various reasons.
400   o  referralURI.localReference.  See Section 3.1.2.  This field must
401      be allowed by the URI specification, but may be omitted in URI
402      instances for various reasons.
403   o  referralURI.searchScope.  See Section 3.1.5.  This field must be
404      allowed by the URI specification, but may be omitted in URI
405      instances for various reasons.
406   o  referralURI.searchedSubtrees.  See Section 3.1.6.  This field must
407      be allowed by the URI specification, but may be omitted in URI
408      instances for various reasons.
409   o  referralURI.failedName.  See Section 3.1.7.  This field must be
410      allowed by the URI specification, but may be omitted in URI
411      instances for various reasons.
412
413
4143.1.2  ContinuationReference.localReference
415
416
417   This names the DSE which was found to hold distributed knowledge
418   information, and thus which caused the ContinuationReference to be
419   formed.  This field is primarily used to help convey the new target
420   object name, but may also be used for purposes referential integrity
421   (not discussed here).  In the event that the root object holds the
422   distributed knowledge information, this field is present and is
423   populated with an empty DN.
424
425
4263.1.3  ContinuationReference.referenceType
427
428
429   Indicates the DSE Type of the ContinuationReference.localReference.
430   This field may be used to determine how to progress an operations
431   (i.e.  if the value is nonSpecificSubordinate, a search continuation
432   will exclude the ContinuationReference.referenceType).
433
434
435
436
437
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442
443
4443.1.4  ContinuationReference.remainingName
445
446
447   In certain scenarios, the localReference does not completely name the
448   DSE to be used as the new target object name.  In these cases,
449   remainingName is populated with the RDNSequence relative to the
450   localReference of the target object name being resolved.  Some
451   examples of these scenarios include (but are not restricted to):
452
453
454   o  During name resolution, the name is not fully resolved, but a DSE
455      holding distributed knowledge information is found, causing a
456      ContinuationReference to be generated.
457   o  While searching, an alias is dereferenced.  The aliasedObjectName
458      points to a DSE of type glue which is subordinate to a DSE holding
459      distributed knowledge information.
460
461
4623.1.5  ContinuationReference.searchScope
463
464
465   Under certain circumstances, when progressing a search operation, a
466   search scope different than that of the original search request must
467   be used.  This field facilitates the conveyance of the proper search
468   scope to be used when progressing the distributed operation.
469
470
471   The scope of subordinateSubtree has been added to the values allowed
472   by the LDAP SearchRequest.scope field.  This scope includes the
473   subtree of entries below the base DN, but does not include the base
474   DN itself.  This is used here when progressing distributed search
475   operations caused by the existence of a DSE of type nssr.
476
477
478   If a referralURI.searchScope is present, it overrides this field
479   while that referralURI is being operated upon.
480
481
4823.1.6  ContinuationReference.searchedSubtrees
483
484
485   For ContinuationReferences generated while processing a search
486   operation with a scope of wholeSubtree, each value of this field
487   indicates that a particular subtree below the target object has
488   already been searched.  Consumers of this data use it to cause the
489   progression of the search operation to exclude these subtrees as a
490   mechanism to avoid receiving duplicate entries.
491
492
493   If a referralURI.searchedSubtrees is present, it overrides this field
494   while that referralURI is being operated upon.
495
496
4973.1.7  ContinuationReference.failedName
498
499
500   When an operation requires that multiple names be resolved (as is the
501   case with the ModifyDN operation), this field is used to specify
502   which name was found to be non-local.
503
504
505
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510
511
512   If a referralURI.failedName is present, it overrides this field while
513   that referralURI is being operated upon.
514
515
5163.2  ChainedRequest
517
518
519   The Chained Request is sent as an LDAP extended operation.  The
520   requestName is IANA-ASSIGNED-OID.1.  The requestValue is the BER
521   encoding of the following ChainedRequestValue ASN.1 definition:
522
523
524      ChainedRequestValue ::= SEQUENCE {
525
526
527         chainingArguments ChainingArguments,
528         operationRequest  OperationRequest }
529
530
531      ChainingArguments ::= SEQUENCE {
532
533
534         targetObject     [0] LDAPDN OPTIONAL,
535         referenceType    [1] ReferenceType,
536         traceInformation [2] ChainingTraceInformation,
537         searchScope      [3] SearchScope OPTIONAL,
538         searchedSubtrees [4] SearchedSubtrees OPTIONAL}
539
540
541      ChainingTraceInformation ::= SET OF LDAPURL
542
543
544      OperationRequest ::= SEQUENCE {
545
546
547         Request ::= CHOICE {
548
549
550            bindRequest    BindRequest,
551            searchRequest  SearchRequest,
552            modifyRequest  ModifyRequest,
553            addRequest     AddRequest,
554            delRequest     DelRequest,
555            modDNRequest   ModifyDNRequest,
556            compareRequest CompareRequest,
557            extendedReq    ExtendedRequest,
558            ...  },
559         controls       [0] Controls COPTIONAL }
560
561
562   BindRequest, SearchRequest, ModifyRequest, AddRequest, DelRequest,
563   ModifyDNRequest, CompareRequest, ExtendedRequest and Controls are
564   defined in [RFC2251].
565
566
5673.2.1  ChainedRequestValue.chainingArguments
568
569
570   In general, these fields assist in refining the original operation as
571   it is to be executed on the receiving DSA.
572
573
574
575
576
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580
581
5823.2.1.1  ChainedRequestValue.chainingArguments.targetObject
583
584
585   This field contains the new target (or base) DN for the operation.
586
587
588   The sending DSA populates this under different scenarios including
589   the case where an alias has been dereferenced while resolving the DN,
590   and also the case where a referral carries a target name different
591   from the reference object that caused the referral.
592
593
594   This field can be omitted only if it would be the the same value as
595   the object or base object parameter in the
596   ChainedRequestValue.operationRequest, in which case its implied value
597   is that value.
598
599
600   The receiving DSA examines this field and (if present) uses it rather
601   than the base DN held in the ChainedRequestValue.operationRequest.
602
603
6043.2.1.2  ChainedRequestValue.chainingArguments.referenceType
605
606
607   See Section 3.1.3.
608
609
610   If the receiver encounters a value of nonSpecificSubordinate in this
611   field, it indicates that the operation is being chained due to DSE of
612   type nssr.  In this case, the receiver allows (and expects) the base
613   DN to name the immediate superior of a context prefix.
614
615
6163.2.1.3  ChainedRequestValue.chainingArguments.traceInformation
617
618
619   This contains a set of URIs.  Each value represents the address of a
620   DSA and DN that has already been contacted while attempting to
621   service the operation.  This field is used to detect looping while
622   servicing a distributed operation.
623
624
625   The sending DSA populates this with its own URI, and also the URIs of
626   any DSAs that have already been chained to.  The receiving DSA
627   examines this list of URIs and returns a loopDetect error if it finds
628   that any of the addresses and DNs in the listed URI's represent it's
629   own.
630
631
6323.2.1.4  ChainedRequestValue.chainingArguments.searchScope
633
634
635   See Section 3.1.5.
636
637
6383.2.1.5  ChainedRequestValue.chainingArguments.searchedSubtrees
639
640
641   See Section 3.1.6.
642
643
644
645
646
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651
652
6533.2.2  ChainedRequestValue.operationRequest
654
655
656   This holds the original LDAP operation request.  This is restricted
657   to a subset of all LDAP operations.  Namely, the following LDAP
658   operation types are not allowed:
659
660
661   o  Abandon/Cancel operations.  When an abandon or cancel operation
662      needs to be chained, it is sent to the remote DSA as-is.  This is
663      because there is no need to track it for loop detection or pass on
664      any other information normally found in ChainingArguments.
665   o  Unbind.  Again, there is no need to send chaining-related
666      information to a DSA to perform an unbind.  DSAs which chain
667      operations maintain connections as they see fit.
668   o  Chained Operation.  When a DSA receives a chained operation, and
669      must again chain that operation to a remote DSA, it sends a
670      ChainedRequest where the ChainedRequestValue.operationRequest is
671      that of the incoming ChainedRequestValue.operationRequest.
672
673
6743.3  Chained Response
675
676
677   The Chained Response is sent as an LDAP IntermediateResponse
678   [RFC3771], or LDAP ExtendedResponse [RFC2251], depending on whether
679   the operation is complete or not.  In either case, the responseName
680   is omitted.  For intermediate responses, the
681   IntermediateResponse.responseValue is the BER encoding of the
682   ChainedIntermediateResponseValue ASN.1 definition.  For completed
683   operations, the ExtendedResponse.value is the BER encoding of the
684   ChainedFinalResponseValue ASN.1 definition.
685
686
687      ChainedIntermediateResponseValue ::= SEQUENCE {
688
689
690         chainedResults    ChainingResults,
691         operationResponse IntermediateResponse }
692
693
694      ChainedFinalResponseValue ::= SEQUENCE {
695
696
697         chainedResults    ChainingResults,
698         operationResponse FinalResponse }
699
700
701      ChainingResults ::= SEQUENCE {
702
703
704         searchedSubtrees [0] SearchedSubtrees OPTIONAL,
705         ...  }
706
707
708      IntermediateResponse ::= SEQUENCE {
709
710
711         Response ::= CHOICE {
712
713
714
715
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720
721
722
723            searchResEntry       SearchResultEntry,
724            searchResRef         SearchResultReference,
725            intermediateResponse IntermediateResponse
726            ...  },
727         controls [0] Controls COPTIONAL }
728
729
730      FinalResponse ::= SEQUENCE {
731
732
733         Response ::= CHOICE {
734
735
736            bindResponse    BindResponse,
737            searchResDone   SearchResultDone,
738            modifyResponse  ModifyResponse,
739            addResponse     AddResponse,
740            delResponse     DelResponse,
741            modDNResponse   ModifyDNResponse,
742            compareResponse CompareResponse,
743            extendedResp    ExtendedResponse,
744            ...  },
745         controls [0] Controls COPTIONAL }
746
747
748   BindResponse, SearchResultEntry, SearchResultDone,
749   SearchResultReference, ModifyResponse, AddResponse, DelResponse,
750   ModifyDNResponse, CompareResponse, ExtendedResponse, and Controls are
751   defined in [RFC2251].  IntermediateResponse is defined in [RFC3771].
752
753
7543.3.1  ChainingResults
755
756
757   In general, this is used to convey additional information that may
758   needed in the event that the operation needs to be progressed
759   further.
760
761
7623.3.1.1  ChainingResults.searchedSubtrees
763
764
765   Each value of this field indicates that a particular subtree below
766   the target object has already been searched.  This is particularly
767   useful while chaining search operations during operation evaluation
768   caused by the presence of a DSA of type nssr.  Each DSA referenced by
769   the nssr holds one or more naming contexts subordinate to the nssr
770   DSE.  The ChainingResults.searchedSubtrees field allows the DSA being
771   chained to, to inform the sending DSA which subordinate naming
772   contexts have been searched.  This information may be passed to
773   further DSAs listed on the nssr in order to reduce the possibility of
774   duplicate entries being returned.
775
776
777
778
779
780
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785
786
7873.3.2  ChainedIntermediateResponseValue.intermediateResponse and
788      ChainedFinalResponseValue.finalResponse
789
790
791   This holds the directory operation response message tied to the
792   ChainedRequestValue.operationRequest.
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
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843
844
8454.  Distributed Procedures
846
847
848   For the purposes of describing a distributed operation, operations
849   are said to consist of two major phases -- name resolution and
850   operation evaluation.  These terms are adopted from [X518].  Name
851   resolution is the act of locating a DSE said to be held locally by a
852   DSA given a distinguished name (DN).  Operation evaluation is the act
853   of performing the operation after the name resolution phase is
854   complete.
855
856
857   Furthermore, there are two modes of distributing an operation --
858   chaining, and returning referrals.  Chaining is the act of forwarding
859   an unfinished operation to another DSA for completion (this may
860   happen during name resolution or operation evaluation).  In this
861   case, the forwarding DSA sends a chained operation to a receiving
862   DSA, which attempts to complete the operation.  Alternately, the DSA
863   may return a referral (or intermediate referral), and the client may
864   use that referral in order to forward the unfinished operation to
865   another DSA.  Whether the operation is distributed via chaining or
866   referrals is a decision left to the DSA and or DUA.
867
868
869   The term 'intermediate referral' describes a referral returned during
870   the operation evaluation phase of an operation.  These include
871   searchResultReferences, referrals returned with an
872   intermediateResponse [RFC3771], or future referrals which indicate
873   that they are intermediate referrals.
874
875
876   An operation which is distributed while in the operation evaluation
877   phase is termed a 'sub-operation'.
878
879
880   This document inserts a step between the two distributed operation
881   phases in order to commonize the data and processes followed prior to
882   chaining an operation or returning a referral.  This step consists of
883   populating a ContinuationReference data type.
884
885
8864.1  Name resolution
887
888
889   Before evaluating (enacting) most directory operations, the DSE named
890   by the target (often called the base DN) of the operation must be
891   located .  This is done by evaluating the RDNs of the target DN one
892   at a time, starting at the rootmost RDN.  Each RDN is compared to the
893   DSEs held by the DSA until the set of RDNs is exhausted, or an RDN
894   cannot be found.
895
896
897   If the DSE named by the target is found to be local, the name
898   resolution phase of the operation completes and the operation
899   evaluation phase begins.
900
901
902
903
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908
909
910   If it is found that the target does not name a local DSE nor a DSE
911   that may held by another DSA, it is said that the target does not
912   exist, and the operation fails with noSuchObject (subject to local
913   policy).
914
915
916   If it is found that the DSE named by the target is non-local to the
917   DSA, but may reside elsewhere, name resolution is said to be
918   incomplete.  In this case, the operation may be distributed by
919   creating a ContinuationReference (Section 4.3) and either chaining
920   the operation (Section 4.4 and Section 4.5)or returning a referral
921   (Section 4.9).
922
923
9244.1.1  Determining that a named DSE is local to a DSA
925
926
927   If a DSE held by a DSA falls within a naming context held by the DSA,
928   or is the root DSE on a first-level DSA, it is said to be local to
929   that DSA
930
931
9324.1.2  Determining that a named DSE does not exist
933
934
935   A named DSE is said to not exist if, during name resolution the DSE
936   is not found, but if found it would fall within a naming context held
937   by the DSA.
938
939
9404.1.3  Determining that a named DSE is non-local
941
942
943   If a named DSE is niether found to be local to the DSA, nor found to
944   not exist, it is said to be non-local to a DSA.  In this case, it is
945   indeterminate whether the named DSE exists.
946
947
948   When a named DSE is found to be non-local, there should be
949   distributed knowledge information available to be used to either
950   return a referral or chain the operation.
951
952
9534.1.3.1  Locating distributed knowledge information for a non-local
954        target
955
956
957   If it has been determined that a target names a non-local DSE,
958   distributed knowledge information may be found by first examining the
959   DSE named by the target, and subsequently all superior DSEs beginning
960   with the immediate superior and ending with the root, until an
961   examined DSE is one of types:
962
963
964   {TODO: should DSE types be all caps? It would be easier to read.}
965   o  subr
966   o  supr
967   o  immsupr
968
969
970
971
972
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976
977
978   o  xr
979   o  nssr
980
981
982   The examined DSE which is of one of these types holds the distributed
983   knowledge information for the non-local named target.  This DSE is
984   said to be the found distributed knowledge information of the
985   non-local target.  This found distributed knowledge information may
986   then be used to distribute the operation.
987
988
989   If no examined DSEs are of any of these types, the distributed
990   knowledge information is mis-configured, and the error
991   invalidReference is returned.
992
993
9944.1.4  Special case for the Add operation
995
996
997   During the name resolution phase of the Add operation, the immediate
998   parent of the base DN is resolved.
999
1000
1001   If the immediate parent of the entry to be added is a DSE of type
1002   nssr, then further interrogation is needed to ensure that the entry
1003   to be added does not exist.  Methods for doing this are found in
1004   Section 4.11.  {TODO: don't make this mandatory.  Also, it doesn't
1005   work without transaction semantics.  Same prob in the mod dn below.}.
1006
1007
10084.1.5  Special case for the ModifyDN operation
1009
1010
1011   When the modifyDN operation includes a newSuperior name, it must be
1012   resolved as well as the base DN being modified.  If either of these
1013   result in a non-local name, the name causing the operation to be
1014   distributed should be conveyed (Section 4.3.5).  {TODO: also mention
1015   access control problems, and mention (impl detail) that
1016   affectsmultidsa can be used.}
1017
1018
1019   If during operation evaluation of a ModifyDN operation, the
1020   newSuperior names a DSE type of nssr, then further interrogation is
1021   needed to ensure that the entry to be added does not exist.  Methods
1022   for doing this are found in Section 4.11.
1023
1024
10254.2  Operation Evaluation
1026
1027
1028   Once name resolution has completed.  The DSE named in the target has
1029   been found to be local to a DSA.  At this point the operation can be
1030   carried out.  During operation evaluation distributed knowledge
1031   information may be found that may cause the DSA to distribute the
1032   operation.  When this happens, the operation may be distributed by
1033   creating a ContinuationReference (Section 4.3) and either chaining
1034   the operation (Section 4.4 and Section 4.5)or returning a referral
1035   (Section 4.9).
1036
1037
1038
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1043
1044
1045   If, during the location of the distributed knowledge information, the
1046   distributed knowledge information is found to be mis-configured,
1047   operation semantics are followed (some operations may call for an
1048   error to be returned, while others call for the error to be ignored).
1049   {TODO: either make this more specific, or less specific, or just toss
1050   it out.}
1051
1052
10534.2.1  Search operation
1054
1055
1056   During operation evaluation of a search operation, the DSA must
1057   determine whether there is distributed knowledge information in the
1058   scope of the search.  Any DSE in the search scope which is of the
1059   following types is considered to be 'found distributed knowledge
1060   information' {TODO: use a better term than found distributed
1061   knowledge information} in the search scope:
1062
1063
1064   o  subr
1065   o  nssr (see nssr note)
1066   o  xr {TODO: I think xr only qualifies when an alias is dereferenced
1067      to an xr.  Otherwisw, there should always be a subr above the xr
1068      if it falls in the search scope.}
1069
1070
1071   Note that due to alias dereferencing, the search scope may expand to
1072   include entries outside of the scope originally specified in the
1073   search operation.  {TODO: note that an aliased object may be glue
1074   which needs to result in any subr or xr above it to be found}
1075
1076
1077   Nssr Note: A DSE of type nssr is only considered to be found
1078   distributed knowledge information when the scope of the search
1079   includes entries below it.  For example, when the search scope is
1080   wholeSubtree or subordinateSubtree and a DSE of type nssr is found in
1081   the scope, or if the search scope is singleLevel and the target
1082   object names a DSE of type nsssr.
1083
1084
1085   {TODO: The following sections are talking about how the continuation
1086   reference is to be populated.  Move to next secion.  Can probably
1087   just say that whole subtree or subordinare subtree encountering nssr,
1088   and single level rooted at nssr result in a continuation reference.
1089   base at, and single level above do not result in a continuation
1090   reference.}
1091
1092
10934.2.1.1  Search operation with singleLevel scope
1094
1095
1096   If distributed knowledge information is found during operation
1097   evaluation of a search with a singleLevel scope, it will cause the
1098   resulting ContinuationReference.searchScope to be set to baseObject.
1099
1100
1101
1102
1103
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1108
1109
11104.2.1.2  Search operation encountering nssr knowledge reference
1111
1112
1113   When a search operation encounters distributed knowledge information
1114   which is a DSE type of nssr during operation evaluation, the
1115   following instructions are followed:
1116
1117
1118   Note that when a search operation is being progressed due to nssr
1119   knowledge information, the subsequent distributed progression of the
1120   search is caused to be applied to each DSA listed as non-specific
1121   knowledge information (This is talked about in Section 4.3.2).  In
1122   the event that multiple DSAs listed in the knowledge information hold
1123   copies of the same directory entries, the 'already searched' and
1124   'duplicate elimination' mechanisms SHOULD be used to prevent
1125   duplicate search result entries from ultimately being returned.
1126
1127
11284.2.1.2.1  wholeSubtree search scope
1129
1130
1131   When the search scope is wholeSubtree, the
1132   ContinuationReference.searchScope is set to subordinateSubtree.
1133   Because the ContinuationReference.referrenceType is set to
1134   nonSpecificSubordinate, the receiving protocol peer allows (and
1135   expects) name resolution to stop at an immsupr DSE type which is
1136   treated as a local DSE.  The subordinateSubtree scope instructs the
1137   receiving protocol peer to exclude the target object from the
1138   sub-search.
1139
1140
11414.2.1.2.2  singleLevel search scope
1142
1143
1144   When the search scope is singleLevel, and the base DN is resolved to
1145   a DSE of type nssr, subsequent distributed progressions of the search
1146   are caused to use the same base DN, and a scope of singleLevel.
1147   Receiving protocol peers will only apply the search to entries below
1148   the target object.
1149
1150
1151   When the search scope is singleLevel and an evaluated DSE is of type
1152   nssr, no special handling is required.  The search is applied to that
1153   DSE if it is of type entry.
1154
1155
11564.2.1.2.3  baseObject search scope
1157
1158
1159   No special handling is needed when the search scope is baseObject and
1160   the base DN is an nssr DSEType.  The search is applied to that DSE if
1161   it is of type entry.
1162
1163
11644.2.1.3  Search operation rooted at an nssr DSE type
1165
1166
1167   (TODO: a subordinateSubtree scope needs to change to wholeSubtree if
1168   references are found.)
1169
1170
1171
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1176
1177
11784.3  Populating the ContinuationReference
1179
1180
1181   When an entry is found to be non-local to a DSA (whether during name
1182   resolution or operation evaluation), the DSA prepares for operation
1183   distribution by generating a ContinuationReference.  This is a
1184   conceptual step, given to help explain the interactions that occur
1185   between discovering that an operation must be distributing, and
1186   actually invoking the operation distribution mechanism.
1187   Implementations are not required to perform this step, but will
1188   effectively work with the same information.
1189
1190
1191   After the ContinuationReference has been created, the DSA may choose
1192   to chain the operation or return a referral (or intermediate
1193   referral(s)).
1194
1195
1196   the ContinuationReference is made up of data held on the found
1197   distributed knowledge information, as well as state information
1198   gained during name resolution or operation evaluation.
1199
1200
12014.3.1  Conveying the Target Object
1202
1203
1204   The consumer of the ContinuationReference will examine various fields
1205   in order to determine the target object name of the operation being
1206   progressed.  The fields examined are the localReference and
1207   remainingName.
1208
1209
1210   If name resolution did not complete, and the found distributed
1211   knowledge information names the same DSE as the base DN of the
1212   operation, the ContinuationReference MAY omit the localReference
1213   and/or remainingName fields.
1214
1215
1216   localReference is populated with the name of the found distributed
1217   knowledge information DSE.  In the event that the root object holds
1218   the distributed knowledge information, this field will be populated
1219   with an empty DN.  Contrast this with the omission of this field.
1220
1221
1222   referenceType is populated with a value reflecting the reference type
1223   of the localReference DSE.
1224
1225
1226   remainingName is populated with the RDNSequence which has not yet
1227   been resolved.  This is the difference between the localReference
1228   value and the name of the DSE to be resolved.
1229
1230
1231   In cases where the DSE named by the {TODO, use a dash or different
1232   term to make 'found distributed knowledge' more like a single term}
1233   found distributed knowledge is not the same as the base DN of the
1234   operation, the ContinuationReference must contain the localReference
1235   and/or remainingName fields.  Such cases include but are not limited
1236
1237
1238
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1243
1244
1245   to:
1246
1247
1248   o  Distributed knowledge information is found during operation
1249      evaluation.
1250   o  Aliases were dereferenced during name resolution.
1251   o  Name resolution did not complete and there were remaining RDNs to
1252      be resolved.
1253
1254
12554.3.2  Conveying the Remote DSA
1256
1257
1258   The referralURI field must contain at least one value.  Each
1259   referralURI value must hold a referralURI.accessPoint.  Other
1260   requirements on this field as noted may also apply.
1261
1262
1263   Note for nssr DSE types: During operation evaluation, if a DSE of
1264   type nssr causes the operation to be distributed (the scenarios in
1265   Section 4.2.1.2 are an example), then an intermediate referral {TODO:
1266   this is talking about referral/intermediate referral, but this
1267   section is only dealing with populating continuation reference} is
1268   returned for each value of the ref attribute, where each intermediate
1269   referral only holds a single referralURI value.
1270
1271
12724.3.3  Conveying new search scope
1273
1274
1275   During the evaluation of the search operation, the instructions in
1276   Section 4.2.1.2.1 and Section 4.2.1.2.2 are followed and the
1277   searchScope field is updated with the new search scope.
1278
1279
12804.3.4  Preventing duplicates
1281
1282
1283   In order to prevent duplicate entries from being evaluated while
1284   progressing a search operation, the searchedSubtrees field is
1285   populated with any naming context below the
1286   ContinuationReference.targetObject which have been fully searched.
1287
1288
1289   During the evaluation of the search operation, if the scope is
1290   wholeSubtree, it is possible that the DSA may search the contents of
1291   a naming context which is subordinate to another naming context which
1292   is subordinate to the search base (See figure).
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
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1309
1310
1311                        O X
1312                       / \
1313                      /   \
1314                     /     \
1315                    /       \
1316                    \_______O Y
1317                           /|\
1318                          / | \
1319                         /  |  \
1320                        /   |   \
1321                       A    B    O C
1322                                / \
1323                               /   \
1324                              /     \
1325                             /       \
1326                             \_______/
1327
1328
1329   In this figure, the DSA holds the naming context X and C,Y,X, but not
1330   Y,X.  If the search base was X, an intermediate referral would be
1331   returned for Y,X.  The DSA holding Y,X may also hold a copy of C,Y,X.
1332   In this case, the receiver of the ContinuationReference benefits by
1333   knowing that the DSA already searched C,Y,X so that it can prevent
1334   other DSAs from returning those entries again.
1335
1336
1337   Data already searched is in the form of an RDNSequence, consisting of
1338   the RDNs relative to the target object.
1339
1340
13414.3.5  Conveying the Failed Name
1342
1343
1344   At least one DS operation (modifyDN) requires that multiple DNs be
1345   resolved (the entry being modified and the newSuperior entry).  In
1346   this case, the failedName field will be populated with the DN being
1347   resolved which failed name resolution.  This may aid in the
1348   determination of how the operation is to be progressed.  If both
1349   names are found to be non-local, this field is omitted.
1350
1351
13524.4  Sending a ChainedRequest
1353
1354
1355   When an entry is found to be non-local to a DSA (whether during name
1356   resolution or operation evaluation), the DSA may progress the
1357   operation by sending a chained operation to another DSA (or DSAs).
1358   The instructions in this section assume that a ContinuationReference
1359   has been generated which will be used to form the ChainedRequest.  It
1360   is also assumed that it can be determined whether the operation is
1361   being progressed due to name resolution or due to operation
1362   evaluation.
1363
1364
1365   A DSA which is able to chain operations may advertise this by
1366
1367
1368
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1373
1374
1375   returning a value of IANA-ASSIGNED-OID.2; in the supportedFeatures
1376   attribute on the root DSE.  {TODO: does this and discovery of the
1377   extended op belong in a new 'discovery mechanisms' sections.}
1378
1379
13804.4.1  Forming a ChainedRequest
1381
1382
1383   The following fields are populated as instructed:
1384
1385
13864.4.1.1  ChainedRequestValue.chainingArguments.targetObject
1387
1388
1389   The ContinuationReference may convey a new target object.  If
1390   present, the ContinuationReference.localReference field becomes the
1391   candidate target object.  Otherwise the candidate target object is
1392   assumed to be that of the original directory operation.  Note that an
1393   empty value in the ContinuationReference.localReference field denotes
1394   the root object.
1395
1396
1397   After performing the above determination as to the candidate target
1398   object, any RDNSequence in ContinuationReference.remainingName is
1399   prepended to the determined candidate target object.  This value
1400   becomes the ChainedRequestValue.chainingArguments.targetObject.  If
1401   this value matches the value of the original operation, this field
1402   may be omitted.
1403
1404
14054.4.1.2  ChainedRequestValue.chainingArguments.referenceType
1406
1407
1408   This is populated with the
1409   ContinuationReference.referralURI.referenceType.
1410
1411
14124.4.1.3  ChainedRequestValue.chainingArguments.traceInformation
1413
1414
1415   This is populated as specified in Section 3.2.1.3.
1416
1417
14184.4.1.4  ChainedRequestValue.chainingArguments.searchScope
1419
1420
1421   This is populated with the
1422   ContinuationReference.referralURI.searchScope if present, otherwise
1423   by the ContinuationReference.searchScope if present, and not
1424   populated otherwise.
1425
1426
14274.4.1.5  ChainedRequestValue.chainingArguments.searchedSubtrees
1428
1429
1430   This is populated with ContinuationReference.searchedSubtrees, as
1431   well as any previously received values of
1432   ChainedFinalResponseValue.chainingResults.searchedSubtrees or
1433   ChainedIntermediateResponseValue.chainingResults.searchedSubtrees
1434   which are subordinate, relative to the target object.  (If thsi is
1435   relative to the target object, it can't contain non-relative
1436
1437
1438
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1443
1444
1445   subtrees)
1446
1447
14484.4.1.6  ChainedRequestValue.operationRequest
1449
1450
1451   This is populated with the original directory operation request.
1452
1453
14544.4.2  Attempting Each Referral URI
1455
1456
1457   A ContinuationReference consists of one or more referralURIs which
1458   represent(s a) remote DSA(s).  The chaining DSA attempts to chain to
1459   each of these DSAs until one succeeds in completing the operation.
1460   An operation is considered to be completed if it reaches the remote
1461   DSA and a response is sent back that indicates that the operation was
1462   executed.  Operations which are sent to the remote DSA, but don't
1463   complete are indicated by a result code of unavailable or busy.  A
1464   result code of protocolError may indicate that the DSA does not
1465   support the chained operation, and in this case, it is also treated
1466   as an uncompleted operation.  Other errors may in the future specify
1467   that they also indicate non-completion.  Note that the response may
1468   itself contain referral(s), these are still considered completed
1469   operations and thus would subsequently be handled and chained.
1470   {TODO: could use soft/hard, or transient/permanent
1471   referral/non-referral error terms here.}
1472
1473
14744.4.3  Loop Prevention
1475
1476
1477   Prior to sending a ChainedRequest, the DSA may attempt to prevent
1478   looping scenarios by comparing {TODO: what matching rule is used?
1479   Suggest we don't convert dns names to ip addresses due to NATs} the
1480   address of the remote DSA and target object to the values of
1481   ChainedRequestValue.chainingArguments.traceInformation.  If a match
1482   is found, the DSA returns a loopDetect error.  Note that while this
1483   type of loop prevention aids in detecting loops prior to sending data
1484   to a remote DSA, it is not a substitute for loop detection (Section
1485   Section 4.6.2).  This is because the sending DSA is only aware of a
1486   single address on which the receiving DSA accepts connections.
1487
1488
14894.5  Emulating the Sending of a ChainedRequest
1490
1491
1492   When it is determined that the operation cannot be distributed by
1493   means of the ChainedRequest, the chaining DSA may instead emulate the
1494   steps involved in chaining the operation.  These steps consist of
1495   performing loop prevention, forming a new directory operation request
1496   from the original request and possibly updating the base DN, search
1497   scope, and search filter(in order to emulate searchedSubtrees), and,
1498   similar to the steps in Section 4.4.2, attempting to send the
1499   operation request to each DSA listed in the
1500   ContinuationReference.referralURI until one succeeds in completing
1501
1502
1503
1504
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1508
1509
1510   the operation.
1511
1512
1513   {TODO: We need a way (control) to tell the receiver to allow name
1514   resolution to end on the parent of a cp (typically an immsupr).  This
1515   would be sent when the ContinuationReference.referenceType is
1516   nonSpecificSubordinate}
1517
1518
15194.5.1  Emulated Loop Detection
1520
1521
1522   For this step, the loop prevention instructions in Section 4.4.3 are
1523   followed.  Note that this method of loop detection may actually allow
1524   some looping to occur before the loop is detected.
1525
1526
15274.5.2  Forming the New Request
1528
1529
1530   The new directory operation request is formed from the fields of the
1531   original request, and the following fields may be updated:
1532
1533
1534   o  The base DN is formed from the new target object as determined by
1535      following the instructions in Section 4.4.1.1 and using the value
1536      which would have been placed in
1537      ChainedRequestValue.chainingArguments.targetObject.
1538   o  For the search operation, the scope is populated with
1539      ContinuationReference.searchScope if present, otherwise the scope
1540      of the original operation request is used.
1541   o  For the search operation, if the
1542      ContinuationReference.searchedSubtrees field is present, causes
1543      the search filter to be augmented by adding a filter item of the
1544      'and' CHOICE.  The filter consists of {TODO: weasel Kurt into
1545      finishing his entryDN draft and reference the appropriate section
1546      there.  See
1547      <http://www.openldap.org/lists/ietf-ldapext/200407/msg00000.html>
1548      for context}
1549   o  Other fields (such as the messageID, and non-critical controls)
1550      may also need to be updated or excluded.
1551
1552
1553   If the service being chained to does not support directory
1554   operations, other operations may be used as long as they provide the
1555   same level as service as those provided by the analogous directory
1556   operation.
1557
1558
15594.6  Receiving a ChainedRequest
1560
1561
1562   A DSA which is able to receive and service a ChainedRequest may
1563   advertise this feature by returning a value of IANA-ASSIGNED-OID.1 in
1564   the supportedExtension attribute of the root DSE.  {TODO: move?}
1565
1566
1567   The ChainedRequestValue data type is the requestValue of an
1568
1569
1570
1571
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1574
1575
1576
1577   extendedRequest.
1578
1579
1580   In general, receiving and servicing a ChainedRequest consists of
1581   performing loop detection and, using components of the
1582   ChainedRequestType.chainingArguments along with the
1583   ChainedRequestType.operationRequest, service the request.
1584
1585
15864.6.1  Target Object determination
1587
1588
1589   Prior to checking for a loop condition, the target object must be
1590   determined.  If the ChainedRequestType.chainingArguments.targetObject
1591   field is present, its value becomes the target object.  Otherwise,
1592   the base DN found in the ChainedRequestType.operationRequest becomes
1593   the target object.
1594
1595
15964.6.2  Loop Detection
1597
1598
1599   The loop detection check happens when a DSA receives a chained
1600   operation, prior to acting on the operation.  The DSA compares {TODO:
1601   matching rule? DNS expansion?} each value of
1602   ChainedRequestValue.traceInformation to the list of addresses at
1603   which it accepts directory communications.  A value of
1604   ChainedRequestValue.traceInformation matches when the DSA accepts
1605   directory communications on the address found in the
1606   ChainedRequestValue.traceInformation value, and the target object (as
1607   determined in Section 4.6.1 matches the DN {TODO: using DN matching?}
1608   value found in the ChainedRequestValue.traceInformation value.  If a
1609   match is found the DSA returns a loopDetect result.
1610
1611
16124.6.3  Processing the ChainedRequestValue.operationRequest
1613
1614
1615   In processing the operationRequest, the DSA uses the target object
1616   determined in Section 4.6.1.  For search operations, it uses the
1617   scope found in ChainedRequestValue.chainingArguments.searchScope, and
1618   excludes any subtrees relative to the target object indicated in
1619   ChainedRequestValue.chainingArguments.searchedSubtrees.
1620
1621
1622   Responses are returned in the form of a Chained Response.
1623
1624
16254.7  Returning a Chained Response
1626
1627
1628   When returning responses to a ChainedRequest, the Chained Response as
1629   documented in Section 3.3 is used.  If the
1630   ChainedFinalResponseValue.operationResponse is a searchResultDone,
1631   the ChainedFinalResponseValue.chainingResults.searchedSubtrees field
1632   is populated with values consisting of the RDNSequence relative to
1633   the target object of naming contexts that the DSA searched.  See
1634   Section 3.3.1.1 for details on why this is done.
1635
1636
1637
1638
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1641
1642
1643
16444.7.1  Chained Response resultCode
1645
1646
1647   The resultCode for the Chained Response is distinct from the result
1648   code of the ChainedIntermediateResponseValue.intermediateResponse or
1649   ChainedFinalResponseValue.finalResponse.  If the act of chaining the
1650   operation completed, then this value will be success.  Other result
1651   codes refer to the chained operation itself, and not the result of
1652   the embedded operation.
1653
1654
16554.7.2  Returning referrals in the Chained Response
1656
1657
1658   {TODO: it would be less complicated if rather than using the simple
1659   LDAP URL, we used the ContinuationReference type to return referrals
1660   and intermediate referrals.} {TODO: We need an example of why we
1661   should allow referrals on a chained response.  Why not just use the
1662   referral field in the operation?}
1663
1664
16654.8  Receiving a Chained Response
1666
1667
1668   Processing a received Chained Response is generally straight forward
1669   -- typically the response is simply extracted and returned, but there
1670   are some extra steps to be taken when chaining sub-operations.
1671
1672
16734.8.1  Handling Sub-operation controls and result codes
1674
1675
1676   When sub-operations are chained, there is the possibility that
1677   different result codes will be encountered.  Similarly, if controls
1678   which elicit response controls were attached to the operation, it's
1679   possible that multiple response controls will be encountered.  Both
1680   of these possibilities require that the chaining DSA take appropriate
1681   steps to ensure that the response being returned is correct.
1682
1683
1684   In general, when a result code indicating an error is received, the
1685   operation will terminate and the error will be returned.  In cases
1686   where multiple sub-operations are being concurrently serviced, the
1687   operation will terminate and the most relevant, or first received
1688   result code is returned -- determining the result code to be returned
1689   in this case is a local matter.
1690
1691
1692   A DSA which chains an operation having a control (or controls)
1693   attached must ensure that a properly formed response is returned.
1694   This requires that the DSA understand and know how to aggrigate the
1695   results of all controls which it allows to remain attached to an
1696   operation being chained.  If the DSA does not understand or support a
1697   control which is marked non-critical, it removes the control prior to
1698   chaining the operation.  The DSA may return
1699   unavailableCriticalExtension for critical controls that it cannot or
1700   will not chain.  {TODO: give SSS as an example?}
1701
1702
1703
1704
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1707
1708
1709
17104.8.1.1  Handling referrals during sub-operations
1711
1712
1713   If a referral is returned in response to a sub-operation, the sending
1714   DSA may attempt to further chain the operation.  In the event that
1715   the DSA does not further chain the sub-operation, it will use the
1716   referral to construct an intermediate referral, and return it
1717   appropriately.  When using a referral to construct an intermediate
1718   referral, certain transformations may have to happen.  For example,
1719   when using a referral to construct a searchResultReference, it must
1720   be assured that the <dn> field is present, and that the <scope> field
1721   is properly updated.
1722
1723
17244.8.2  Duplicate Elimination
1725
1726
1727   When search result references cause the DSA to chain a search, it is
1728   possible that duplicate objects will be returned by different remote
1729   DSAs.  These duplicate objects must be sensed and not returned.
1730
1731
1732   {TODO: Even though there are costs associated with returning
1733   duplicates, is it a worthy exercise to build in an allowance for them
1734   to be returned? In other words, do we want to add a way for a client
1735   (or administrator) to say "it's ok, return the duplicates, let the
1736   client deal with them"? Allowing is seen as a cost benefit to the
1737   DSA.}
1738
1739
17404.9  Returning a Referral or Intermediate Referral
1741
1742
1743   There are two ways in which the fields of the ContinuationReference
1744   may be conveyed in a response containing or consisting of referral or
1745   intermediate referral.  A paired control is introduced for the
1746   purpose of soliciting and returning a ContinuationReference.  In
1747   absence of this control, a referral or intermediate referral may be
1748   returned which conveys the information present in the
1749   ContinuationReference.  A method of converting a
1750   ContinuationReference to an LDAP URL is provided for referrals and
1751   intermediate referrals which identify LDAP-enabled DSAs.  Methods for
1752   converting a ContinuationReference to URIs which identify non-LDAP
1753   servers is not provided here, but may be specified in future
1754   documents, as long as they can represent the data needed to provide
1755   the same level of service.
1756
1757
17584.9.1  ReturnContinuationReference controls
1759
1760
1761   This control is sent when a client wishes to receive a
1762   ContinuationReference in the event that a referral or intermediate
1763   referral is being returned.  If returned, the ContinuationReference
1764   will hold all data but the referralURI field.  the referralURI values
1765   will be held in the referral or intermediate referral (Referral,
1766
1767
1768
1769
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1772
1773
1774
1775   SearchResultReference, etc.).
1776
1777
17784.9.1.1  ReturnContinuationReference request control
1779
1780
1781   Solicits the return of a ReturnContinuationReference response control
1782   on messages consisting of (or carrying) a referral or intermediate
1783   referral.  The controlType is IANA-ASSIGNED-OID.3, the criticality is
1784   set at the sender's discretion, the controlValue is omitted.
1785
1786
17874.9.1.2  ReturnContinuationReference response control
1788
1789
1790   In response to the ReturnContinuationReference request control, this
1791   holds a ContinuationReference for messages consisting of (or
1792   carrying) a referral or intermediate referral.  The controlType is
1793   IANA-ASSIGNED-OID.3, the controlValue is the BER-encoding of a
1794   ContinuationReference.  Note that the referralURI field is optionally
1795   omitted when the ContinuationReference is sent in this control value.
1796   In this event, the URI(s) found in the referral or intermediate
1797   referral (Referral, SearchContinuationReference, etc.) are to be used
1798   in its stead.  {TODO: is returining the referralURI outside an
1799   unneeded complication?}
1800
1801
18024.9.2  Converting a ContinuationReference to an LDAP URL
1803
1804
1805   This section details the way in which an LDAP URL (from the referral
1806   or intermediate referral) is used to convey the fields of a
1807   ContinuationReference.  Where existing LDAP URL fields are
1808   insufficient, extensions are introduced.  Note that further
1809   extensions to the ContinuationReference type require further
1810   specifications here.  {TODO: explain that each ldap url in the
1811   continuation refrerence is examined and converted}
1812
1813
1814   These instructions must be applied to each LDAP URL value within the
1815   referral or intermediate referral.
1816
1817
18184.9.2.1  Conveying the target name
1819
1820
1821   If the <dn> part of the LDAP URL is already present, it is determined
1822   to be the candidate target object.  Otherwise, the candidate target
1823   object comes from the ContinuationReference.localReference.  Once the
1824   candidate target object is determined, the value of
1825   ContinuationReference.remainingName is prepended to the candidate
1826   target object.  This new value becomes the target object and its
1827   string value (as specified by <distinguishedName> in [RFC2253]) is
1828   placed in the <dn> part of the LDAP URL.
1829
1830
1831
1832
1833
1834
1835
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1838
1839
1840
18414.9.2.2  ContinuationReference.localReference
1842
1843
1844   This is conveyed as an extension.  The extype is IANA-ASSIGNED-OID.4
1845   or the descriptor 'localReference', and the exvalue is the string DN
1846   encoding (as specified by <distinguishedName> in [RFC2253]) of the
1847   ContinuationReference.localReference value.
1848
1849
18504.9.2.3  ContinuationReference.referenceType
1851
1852
1853   This is conveyed as an extension.  The extype is IANA-ASSIGNED-OID.5
1854   or the descriptor 'referenceType'.  If the
1855   ContinuationReference.referenceType is one of superior, subordinate,
1856   cross, nonSpecificSubordinate, suplier, master, immediateSuperior, or
1857   self, the exvalue 'superior', 'subordinate', 'cross',
1858   'nonSpecificSubordinate', 'suplier', 'master', 'immediateSuperior',
1859   or 'self' respectively.
1860
1861
18624.9.2.4  ContinuationReference.searchScope
1863
1864
1865   If the search scope is one of baseObject, singleLevel, or
1866   wholeSubtree, then it may be conveyed in the 'scope' part of the LDAP
1867   URL as 'base', 'one', or 'sub' respectively.  If the search scope is
1868   subordinateSubtree, then it may be conveyed in the <extension> form
1869   as documented in [LDAP-SUBORD].  If this extension is present, it
1870   MUST be marked critical.  This ensures that a receiver which is
1871   unaware of this extension uses the proper search scope, or fails to
1872   progress the operation.
1873
1874
18754.9.2.5  ContinuationReference.searchedSubtrees
1876
1877
1878   This field is conveyed as an extension.  The extype is
1879   IANA-ASSIGNED-OID.6 or the descriptor 'searchedSubtrees', and the
1880   exvalue is the ContinuationReference.searchedSubtree value encoded
1881   according to the following searchedSubtrees ABNF:
1882
1883
1884      searchedSubtrees = 1*(LANGLE searchedSubtree RANGLE)
1885      searchedSubtree = <distinguishedName> from [RFC2253]
1886      LANGLE  = %x3C ; left angle bracket ("<")
1887      RANGLE  = %x3E ; right angle bracket (">")
1888
1889
1890   Each searchedSubtree represents one RDNSequence value in the
1891   ContinuationReference.searchedSubtree field.  An example of a
1892   searchedSubtrees value containing two searched subtrees is:
1893   <dc=example,dc=com><cn=ralph,dc=users,dc=example,dc=com>.
1894
1895
18964.9.2.6  ContinuationReference.failedName
1897
1898
1899   This field is conveyed as an extension.  The extype is
1900
1901
1902
1903
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1906
1907
1908
1909   IANA-ASSIGNED-OID.7 or the descriptor 'failedName', and the exvalue
1910   is the string DN encoding (as specified in [RFC2253]) of the
1911   ContinuationReference.failedName value.
1912
1913
19144.10  Acting on a Referral or Intermediate Referral
1915
1916
1917   When a protocol peer receives a referral or intermediate referral, it
1918   may distribute the operation either by sending a ChainedRequest, or
1919   by emulating the ChainedRequest.  Prior to taking these steps, the
1920   protocol peer effectively converts the referral or intermediate
1921   referral into a ContinuationReference.  Then, acting in the same
1922   manner as a DSA would, follows the directions in Section 4.4 if
1923   sending a ChainedRequest, or Section 4.5 otherwise.
1924
1925
19264.10.1  Converting a Referral or Intermediate Referral to a
1927       ContinuationReference
1928
1929
1930   A referral or intermediate referral may be converted (or conceptually
1931   converted) to a ContinuationReference type in order to follow the
1932   distributed operation procedures in Section 4.4, or Section 4.5.  The
1933   following steps may only be used to convert a referral or
1934   intermediate referral containing LDAP URL values.  Converting other
1935   types of URIs may be specified in future documents as long as the
1936   conversion provides the same level of service found here.
1937
1938
1939   o  The ContinuationReference.referralURI is populated with all LDAP
1940      URL values in the referral or intermediate referral.
1941   o  The ContinuationReference.localReference populate with the value
1942      of the localReference extension value (Section 4.9.2.2) if one
1943      exists.  Otherwise it is omitted.
1944   o  The ContinuationReference.referenceType populate with the value of
1945      the referenceType extension value (Section 4.9.2.3) if one exists.
1946      Otherwise it is omitted.
1947   o  The ContinuationReference.remainingName is omitted.
1948   o  The ContinuationReference.searchScope is populated with
1949      subordinateSubtree if the subordScope LDAP URL extension
1950      [LDAP-SUBORD] is present.  If the <scope> field contains te value
1951      'base', 'one', 'sub', or 'subordinates', this filed is populated
1952      with baseObject, singleLevel, wholeSubtree, or subordinateSubtree
1953      respectively.  Otherwise this field is omitted.
1954   o  The ContinuationReference.searchedSubtrees is populated with any
1955      searchedSubtrees LDAP URI extension Section 4.9.2.5 value found on
1956      an LDAP URI in the referral or intermediate referral.  If none
1957      exist, this field is omitted.
1958   o  The ContinuationReference.failedName is populated with any
1959      failedName LDAP URI extension Section 4.9.2.6 value found on an
1960      LDAP URI in the referral or intermediate referral.  If none exist,
1961      this field is omitted.
1962
1963
1964
1965
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1968
1969
1970
1971   Note that many fields are simply omitted.  This is either because
1972   they are conveyed within the LDAP URL values themselves, and
1973   subsequent instructions will check for their presence, or because
1974   they are not needed (they are redundant or not used in further
1975   instructions).
1976
1977
19784.11  Ensuring non-existence of an entry under an nssr
1979
1980
1981   {TODO: add a huge disclaimer here that says without transactional
1982   semantics, you can never be sure that the entry didn't get added.
1983   Maybe we should just punt on this and say it's a local matter} In
1984   order to ensure there are no entries matching the name of the entry
1985   to be added or renamed immediately subordinate to an nssr, these
1986   steps may be followed.
1987
1988
1989   If the DSA is able and allowed to chain operations, it may contact
1990   each of the DSAs listed as access points in the nssr (in the ref
1991   attribute) and using a base-level search operation it will determine
1992   whether or not the object to be added exists.  Note that access
1993   control or other policies may hide the entry from the sending DSA.
1994   If the entry does not exist on any of the DSAs listed in the nssr,
1995   the operation may progress on the local DSA.
1996
1997
1998   If the DSA cannot make this determination, the operation fails with
1999   affectsMultipleDSAs.
2000
2001
20024.12  Mapping a referralURI to an LDAP URI
2003
2004
2005   As with any URI specification which is intended to be used as a URI
2006   which conveys referral information, the LDAP URI specification is
2007   given a mapping to the elements of a referralURI as specified in.
2008   Section 3.1.1.1.  These mappings are given here using the ABNF
2009   identifiers given in [RFC2255].
2010
2011
2012   referralURI to LDAP URI mapping:
2013
2014
2015   +---------------------------------+---------------------------------+
2016   | referralURI element             | LDAP URL element                |
2017   +---------------------------------+---------------------------------+
2018   | protocolIdentifier              | <scheme>                        |
2019   |                                 |                                 |
2020   | accessPoint                     | <hostport>                      |
2021   |                                 |                                 |
2022   | targetObject                    | <dn>. This must be encoded as a |
2023   |                                 | <distinguishedName> as          |
2024   |                                 | specified in [RFC2253]          |
2025   |                                 |                                 |
2026   | localReference                  | LDAP URL localReference         |
2027
2028
2029
2030
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2032Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2033
2034
2035
2036   |                                 | extension as specified in       |
2037   |                                 | Section 4.9.2.2                 |
2038   |                                 |                                 |
2039   | referenceType                   | LDAP URL referenceType          |
2040   |                                 | extension as specified in       |
2041   |                                 | Section 4.9.2.3                 |
2042   |                                 |                                 |
2043   | searchScope                     | <scope> or LDAP URL subordScope |
2044   |                                 | extension as specified in       |
2045   |                                 | Section 4.9.2.4                 |
2046   |                                 |                                 |
2047   | searchedSubtrees                | LDAP URL searchedSubtrees       |
2048   |                                 | extension as specified in       |
2049   |                                 | Section 4.9.2.5                 |
2050   |                                 |                                 |
2051   | failedName                      | LDAP URL failedName extension   |
2052   |                                 | as specified in Section 4.9.2.6 |
2053   +---------------------------------+---------------------------------+
2054
2055
2056
2057 4.13   Using the ManageDsaIT control
2058
2059
2060   This control, defined in [RFC3296], allows the management of the
2061   distributed knowledge information held by a DSA, and thus overrides
2062   the determinations made during name resolution and operation
2063   evaluation.  When this control is attached to an operation, all
2064   resolved and acted upon DSEs are treated as being local to the DSA.
2065   This is true regardless of the phase the operation is in.  Thus
2066   referrals are never returned and chaining never occurs.
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
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2091Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2092
2093
2094
20955.  Security Considerations
2096
2097
2098   This document introduces a mechanism (chaining) which can be used to
2099   propagate directory operation requests to servers which may be
2100   inaccessible otherwise.  Implementers and deployers of this
2101   technology should be aware of this and take appropriate steps such
2102   that firewall mechanisms are not compromised.
2103
2104
2105   This document introduces the ability to return auxiliary data when
2106   returning referrals.  Measures should be taken to ensure proper
2107   protection of his data.
2108
2109
2110   Implementers must ensure that any specified time, size, and
2111   administrative limits are not circumvented due to the mechanisms
2112   introduced here.
2113
2114
21156.  Normative References
2116
2117
2118   [LDAP-SUBORD]
2119              Sermersheim, J., "Subordinate Subtree Search Scope for
2120              LDAP",
2121              Internet-Draft draft-sermersheim-ldap-subordinate-scope,
2122              July 2004.
2123
2124
2125   [RFC2079]  Smith, M., "Definition of an X.500 Attribute Type and an
2126              Object Class to Hold Uniform Resource Identifiers (URIs)",
2127              RFC 2079, January 1997.
2128
2129
2130   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
2131              Requirement Levels", BCP 14, RFC 2119, March 1997.
2132
2133
2134   [RFC2251]  Wahl, M., Howes, T. and S. Kille, "Lightweight Directory
2135              Access Protocol (v3)", RFC 2251, December 1997.
2136
2137
2138   [RFC2253]  Wahl, M., Kille, S. and T. Howes, "Lightweight Directory
2139              Access Protocol (v3): UTF-8 String Representation of
2140              Distinguished Names", RFC 2253, December 1997.
2141
2142
2143   [RFC2255]  Howes, T. and M. Smith, "The LDAP URL Format", RFC 2255,
2144              December 1997.
2145
2146
2147   [RFC2396]  Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform
2148              Resource Identifiers (URI): Generic Syntax", RFC 2396,
2149              August 1998.
2150
2151
2152   [RFC3296]  Zeilenga, K., "Named Subordinate References in Lightweight
2153              Directory Access Protocol (LDAP) Directories", RFC 3296,
2154              July 2002.
2155
2156
2157
2158
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2160Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2161
2162
2163
2164   [RFC3377]  Hodges, J. and R. Morgan, "Lightweight Directory Access
2165              Protocol (v3): Technical Specification", RFC 3377,
2166              September 2002.
2167
2168
2169   [RFC3383]  Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
2170              Considerations for the Lightweight Directory Access
2171              Protocol (LDAP)", BCP 64, RFC 3383, September 2002.
2172
2173
2174   [RFC3771]  Harrison, R. and K. Zeilenga, "The Lightweight Directory
2175              Access Protocol (LDAP) Intermediate Response Message",
2176              RFC 3771, April 2004.
2177
2178
2179   [X500]     International Telephone and Telegraph Consultative
2180              Committee, "The Directory - overview of concepts, models
2181              and services", ITU-T Recommendation X.500, November 1993.
2182
2183
2184   [X518]     International Telephone and Telegraph Consultative
2185              Committee, "The Directory - The Directory: Procedures for
2186              distributed operation", ITU-T Recommendation X.518,
2187              November 1993.
2188
2189
2190   [X680]     International Telecommunications Union, "Abstract Syntax
2191              Notation One (ASN.1): Specification of basic notation",
2192              ITU-T Recommendation X.680, July 2002.
2193
2194
2195   [X690]     International Telecommunications Union, "Information
2196              Technology - ASN.1 encoding rules: Specification of Basic
2197              Encoding Rules (BER), Canonical Encoding Rules (CER) and
2198              Distinguished Encoding Rules (DER)", ITU-T Recommendation
2199              X.690, July 2002.
2200
2201
2202
2203Author's Address
2204
2205
2206   Jim Sermersheim
2207   Novell, Inc
2208   1800 South Novell Place
2209   Provo, Utah  84606
2210   USA
2211
2212
2213   Phone: +1 801 861-3088
2214   Email: jimse@novell.com
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225Sermersheim              Expires August 26, 2005               [Page 34]
2226Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2227
2228
2229
2230Appendix A.  IANA Considerations
2231
2232
2233   Registration of the following values is requested [RFC3383].
2234
2235
2236A.1  LDAP Object Identifier Registrations
2237
2238
2239   It is requested that IANA register upon Standards Action an LDAP
2240   Object Identifier in identifying the protocol elements defined in
2241   this technical specification.  The following registration template is
2242   provided:
2243
2244
2245      Subject: Request for LDAP OID Registration
2246      Person & email address to contact for further information:
2247         Jim Sermersheim
2248         jimse@novell.com
2249      Specification: RFCXXXX
2250      Author/Change Controller: IESG
2251      Comments:
2252      Seven delegations will be made under the assigned OID:
2253      IANA-ASSIGNED-OID.1 ChainedRequest LDAP Extended Operation
2254      IANA-ASSIGNED-OID.2 Supported Feature: Can Chain Operations
2255      IANA-ASSIGNED-OID.3 ReturnContinuationReference LDAP Controls
2256      IANA-ASSIGNED-OID.4 localReference: LDAP URL Extension
2257      IANA-ASSIGNED-OID.6 searchedSubtree: LDAP URL Extension
2258      IANA-ASSIGNED-OID.7 failedName: LDAP URL Extension
2259
2260
2261A.2  LDAP Protocol Mechanism Registrations
2262
2263
2264   It is requested that IANA register upon Standards Action the LDAP
2265   protocol mechanism described in this document.  The following
2266   registration templates are given:
2267
2268
2269      Subject: Request for LDAP Protocol Mechanism Registration
2270      Object Identifier: IANA-ASSIGNED-OID.1
2271      Description: ChainedRequest LDAP Extended Operation
2272      Person & email address to contact for further information:
2273         Jim Sermersheim
2274         jimse@novell.com
2275      Usage: Extension
2276      Specification: RFCXXXX
2277      Author/Change Controller: IESG
2278      Comments: none
2279
2280
2281      Subject: Request for LDAP Protocol Mechanism Registration
2282      Object Identifier: IANA-ASSIGNED-OID.2
2283      Description: Can Chain Operations Supported Feature
2284      Person & email address to contact for further information:
2285
2286
2287
2288
2289
2290Sermersheim              Expires August 26, 2005               [Page 35]
2291Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2292
2293
2294
2295         Jim Sermersheim
2296         jimse@novell.com
2297      Usage: Feature
2298      Specification: RFCXXXX
2299      Author/Change Controller: IESG
2300      Comments: none
2301
2302
2303      Subject: Request for LDAP Protocol Mechanism Registration
2304      Object Identifier: IANA-ASSIGNED-OID.3
2305      Description: ReturnContinuationReference LDAP Controls
2306      Person & email address to contact for further information:
2307         Jim Sermersheim
2308         jimse@novell.com
2309      Usage: Control
2310      Specification: RFCXXXX
2311      Author/Change Controller: IESG
2312      Comments: none
2313
2314
2315      Subject: Request for LDAP Protocol Mechanism Registration
2316      Object Identifier: IANA-ASSIGNED-OID.4
2317      Description: localReference LDAP URL Extension
2318      Person & email address to contact for further information:
2319         Jim Sermersheim
2320         jimse@novell.com
2321      Usage: Extension
2322      Specification: RFCXXXX
2323      Author/Change Controller: IESG
2324      Comments: none
2325
2326
2327      Subject: Request for LDAP Protocol Mechanism Registration
2328      Object Identifier: IANA-ASSIGNED-OID.5
2329      Description: referenceType LDAP URL Extension
2330      Person & email address to contact for further information:
2331         Jim Sermersheim
2332         jimse@novell.com
2333      Usage: Extension
2334      Specification: RFCXXXX
2335      Author/Change Controller: IESG
2336      Comments: none
2337
2338
2339      Subject: Request for LDAP Protocol Mechanism Registration
2340      Object Identifier: IANA-ASSIGNED-OID.6
2341      Description: searchedSubtree LDAP URL Extension
2342      Person & email address to contact for further information:
2343         Jim Sermersheim
2344         jimse@novell.com
2345      Usage: Extension
2346
2347
2348
2349
2350
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2352Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2353
2354
2355
2356      Specification: RFCXXXX
2357      Author/Change Controller: IESG
2358      Comments: none
2359
2360
2361      Subject: Request for LDAP Protocol Mechanism Registration
2362      Object Identifier: IANA-ASSIGNED-OID.7
2363      Description: failedName LDAP URL Extension
2364      Person & email address to contact for further information:
2365         Jim Sermersheim
2366         jimse@novell.com
2367      Usage: Extension
2368      Specification: RFCXXXX
2369      Author/Change Controller: IESG
2370      Comments: none
2371
2372
2373A.3  LDAP Descriptor Registrations
2374
2375
2376   It is requested that IANA register upon Standards Action the LDAP
2377   descriptors described in this document.  The following registration
2378   templates are given:
2379
2380
2381      Subject: Request for LDAP Descriptor Registration
2382      Descriptor (short name): localReference
2383      Object Identifier: IANA-ASSIGNED-OID.4
2384      Person & email address to contact for further information:
2385         Jim Sermersheim
2386         jimse@novell.com
2387      Usage: URL Extension
2388      Specification: RFCXXXX
2389      Author/Change Controller: IESG
2390      Comments: none
2391
2392
2393      Subject: Request for LDAP Descriptor Registration
2394      Descriptor (short name): referenceType
2395      Object Identifier: IANA-ASSIGNED-OID.5
2396      Person & email address to contact for further information:
2397         Jim Sermersheim
2398         jimse@novell.com
2399      Usage: URL Extension
2400      Specification: RFCXXXX
2401      Author/Change Controller: IESG
2402      Comments: none
2403
2404
2405      Subject: Request for LDAP Descriptor Registration
2406      Descriptor (short name): searchedSubtree
2407      Object Identifier: IANA-ASSIGNED-OID.6
2408      Person & email address to contact for further information:
2409
2410
2411
2412
2413
2414Sermersheim              Expires August 26, 2005               [Page 37]
2415Internet-Draft    Distributed Procedures for LDAP Operations  February 2005
2416
2417
2418
2419         Jim Sermersheim
2420         jimse@novell.com
2421      Usage: URL Extension
2422      Specification: RFCXXXX
2423      Author/Change Controller: IESG
2424      Comments: none
2425
2426
2427      Subject: Request for LDAP Descriptor Registration
2428      Descriptor (short name): failedName
2429      Object Identifier: IANA-ASSIGNED-OID.7
2430      Person & email address to contact for further information:
2431         Jim Sermersheim
2432         jimse@novell.com
2433      Usage: URL Extension
2434      Specification: RFCXXXX
2435      Author/Change Controller: IESG
2436      Comments: none
2437
2438
2439A.4  LDAP Result Code Registrations
2440
2441
2442   It is requested that IANA register upon Standards Action the LDAP
2443   result codes described in this document.  The following registration
2444   templates are given:
2445
2446
2447      Subject: Request for LDAP Result Code Registration
2448      Result Code Name: invalidReference
2449      Person & email address to contact for further information:
2450         Jim Sermersheim
2451         jimse@novell.com
2452      Usage: URL Extension
2453      Specification: RFCXXXX
2454      Author/Change Controller: IESG
2455      Comments: none
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475Sermersheim              Expires August 26, 2005               [Page 38]
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2477
2478
2479
2480Intellectual Property Statement
2481
2482
2483   The IETF takes no position regarding the validity or scope of any
2484   Intellectual Property Rights or other rights that might be claimed to
2485   pertain to the implementation or use of the technology described in
2486   this document or the extent to which any license under such rights
2487   might or might not be available; nor does it represent that it has
2488   made any independent effort to identify any such rights.  Information
2489   on the procedures with respect to rights in RFC documents can be
2490   found in BCP 78 and BCP 79.
2491
2492
2493   Copies of IPR disclosures made to the IETF Secretariat and any
2494   assurances of licenses to be made available, or the result of an
2495   attempt made to obtain a general license or permission for the use of
2496   such proprietary rights by implementers or users of this
2497   specification can be obtained from the IETF on-line IPR repository at
2498   http://www.ietf.org/ipr.
2499
2500
2501   The IETF invites any interested party to bring to its attention any
2502   copyrights, patents or patent applications, or other proprietary
2503   rights that may cover technology that may be required to implement
2504   this standard.  Please address the information to the IETF at
2505   ietf-ipr@ietf.org.
2506
2507
2508
2509Disclaimer of Validity
2510
2511
2512   This document and the information contained herein are provided on an
2513   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
2514   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
2515   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
2516   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
2517   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
2518   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
2519
2520
2521
2522Copyright Statement
2523
2524
2525   Copyright (C) The Internet Society (2005).  This document is subject
2526   to the rights, licenses and restrictions contained in BCP 78, and
2527   except as set forth therein, the authors retain all their rights.
2528
2529
2530
2531Acknowledgment
2532
2533
2534   Funding for the RFC Editor function is currently provided by the
2535   Internet Society.
2536
2537
2538
2539
2540
2541Sermersheim              Expires August 26, 2005               [Page 39]