1 2Network Working Group J;. Sermersheim 3Internet-Draft Novell, Inc 4Updates: 2251 (if approved) July 2004 5Expires: December 30, 2004 6 7 8 Subordinate Subtree Search Scope for LDAP 9 draft-sermersheim-ldap-subordinate-scope-00.txt 10 11Status of this Memo 12 13 This document is an Internet-Draft and is subject to all provisions 14 of section 3 of RFC 3667. By submitting this Internet-Draft, each 15 author represents that any applicable patent or other IPR claims of 16 which he or she is aware have been or will be disclosed, and any of 17 which he or she become aware will be disclosed, in accordance with 18 RFC 3668. 19 20 Internet-Drafts are working documents of the Internet Engineering 21 Task Force (IETF), its areas, and its working groups. Note that 22 other groups may also distribute working documents as 23 Internet-Drafts. 24 25 Internet-Drafts are draft documents valid for a maximum of six months 26 and may be updated, replaced, or obsoleted by other documents at any 27 time. It is inappropriate to use Internet-Drafts as reference 28 material or to cite them other than as "work in progress." 29 30 The list of current Internet-Drafts can be accessed at 31 http://www.ietf.org/ietf/1id-abstracts.txt. 32 33 The list of Internet-Draft Shadow Directories can be accessed at 34 http://www.ietf.org/shadow.html. 35 36 This Internet-Draft will expire on December 30, 2004. 37 38Copyright Notice 39 40 Copyright (C) The Internet Society (2004). 41 42Abstract 43 44 The Lightweight Directory Application Protocol (LDAP) specification 45 supports three scope values for the search operation -- namely: 46 baseObject, singleLevel, and wholeSubtree. This document introduces 47 a subordinateSubtree scope which constrains the search scope to all 48 subordinates of the named base object. 49 50Discussion Forum 51 52 53 54Sermersheim Expires December 30, 2004 [Page 1] 55 56Internet-Draft Subordinate Subtree Search Scope for LDAP July 2004 57 58 59 Technical discussion of this document will take place on the IETF 60 LDAP Extensions mailing list <ldapext@ietf.org>. Please send 61 editorial comments directly to the author. 62 631. Overview 64 65 There are a number of reasons which have surfaced for introducing a 66 Lightweight Directory Application Protocol (LDAP) [RFC3377] 67 SearchRequest.scope [RFC2251] which constrains the search scope to 68 all subordinates of the named base object, and does not include the 69 base object (as wholeSubtree does). These reasons range from the 70 obvious utility of allowing an LDAP client application the ability to 71 exclude the base object from a wholeSubtree search scope, to 72 distributed operation applications which require this scope for 73 progressing search sub-operations resulting from an nssr DSE type 74 reference. 75 76 To meet these needs, the subordinateSubtree scope value is 77 introduced. 78 79 The subordinateSubtrees cope is applied to the SearchRequest.scope 80 field, the <scope> type and alternately the <extension> type of the 81 LDAP URL [RFC2255] and may be applied to other specifications which 82 include an LDAP search scope. A mechanism is also given which allows 83 LDAP Directory Server Agents (DSA)s to advertise support of this 84 search scope. 85 862. Application to SearchRequest.scope 87 88 A new item is added to this ENUMERATED type. The identifier is 89 subordinateSubtree and the number is 4. 90 91 A DSA which receives and supports the subordinateSubtree 92 SearchRequest.scope constrains the search scope to all subordinate 93 objects. 94 95 A DSA which receives but does not support the subordinateSubtree 96 SearchRequest.scope returns a protocolError resultCode in the 97 SearchResultDone. 98 993. LDAP URL applications 100 101 The LDAP URL [RFC2255] specification allows the conveyance of a 102 search scope. This section intoduces two ways in which the 103 subordinateScope search scope may be conveyed in an LDAP URL. One 104 way is by allowing a new "subord" scope in the <scope> part. Another 105 way is through the introduction of an LDAP URL extension. The LDAP 106 URL extension method is preferred for its criticality semantics. 107 108 109 110Sermersheim Expires December 30, 2004 [Page 2] 111 112Internet-Draft Subordinate Subtree Search Scope for LDAP July 2004 113 114 1153.1 Application to LDAP URL <scope> 116 117 A new <scope> value of "subord" is added. Using the <scope> type 118 from LDAP URL [RFC2255], the ABNF is as follows: 119 120 scope /= "subord" 121 122 Implementations processing but which do not understand or support the 123 "subord" <scope> of an LDAP URL raise an appropriate error. 124 1253.2 Application to LDAP URL <extension> 126 127 An LDAP URL <extension> mechanism is introduced here. The <extype> 128 is IANA-ASSIGNED-OID.1 or the descriptor 'subordScope', and the 129 exvalue is omitted. The extension may be marked as either critical 130 or non-critical. 131 132 If supported, the subordScope extension overrides any value set in 133 the <scope> field. 134 1354. DSA Advertisement of support 136 137 A DSA may advertise its support of the subordinateSubtree item in the 138 SearchRequest.scope by inclusion of IANA-ASSIGNED-OID.2 in the 139 'supportedFeatures' attribute of the root DSE. 140 1415. Security Considerations 142 143 This specification introduces no security concerns above any 144 associated with the existing wholeSubtree search scope value. 145 146 As with the wholeSubtree search scope, this scope specifies that a 147 search be applied to an entire subtree hierarchy. Implementations 148 should be aware of the relative cost of using or allowing this scope. 149 1506 Normative References 151 152 [RFC2251] Wahl, M., Howes, T. and S. Kille, "Lightweight Directory 153 Access Protocol (v3)", RFC 2251, December 1997. 154 155 [RFC2255] Howes, T. and M. Smith, "The LDAP URL Format", RFC 2255, 156 December 1997. 157 158 [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access 159 Protocol (v3): Technical Specification", RFC 3377, 160 September 2002. 161 162 [RFC3383] Zeilenga, K., "Internet Assigned Numbers Authority (IANA) 163 164 165 166Sermersheim Expires December 30, 2004 [Page 3] 167 168Internet-Draft Subordinate Subtree Search Scope for LDAP July 2004 169 170 171 Considerations for the Lightweight Directory Access 172 Protocol (LDAP)", BCP 64, RFC 3383, September 2002. 173 174 175Author's Address 176 177 Jim Sermersheim 178 Novell, Inc 179 1800 South Novell Place 180 Provo, Utah 84606 181 USA 182 183 Phone: +1 801 861-3088 184 EMail: jimse@novell.com 185 186Appendix A. IANA Considerations 187 188 Registration of the following values is requested [RFC3383]. 189 190A.1 LDAP Object Identifier Registrations 191 192 It is requested that IANA register upon Standards Action an LDAP 193 Object Identifier in identifying the protocol elements defined in 194 this technical specification. The following registration template is 195 provided: 196 197 Subject: Request for LDAP OID Registration 198 Person & email address to contact for further information: 199 Jim Sermersheim 200 jimse@novell.com 201 Specification: RFCXXXX 202 Author/Change Controller: IESG 203 Comments: 204 2 delegations will be made under the assigned OID: 205 IANA-ASSIGNED-OID.1 subordScope LDAP URL extension 206 IANA-ASSIGNED-OID.2 subordinateScope Supported Feature 207 208A.2 LDAP Protocol Mechanism Registrations 209 210 It is requested that IANA register upon Standards Action the LDAP 211 protocol mechanism described in this document. The following 212 registration templates are given: 213 214 Subject: Request for LDAP Protocol Mechanism Registration 215 Object Identifier: IANA-ASSIGNED-OID.1 216 Description: subordScope LDAP URL extension 217 Person & email address to contact for further information: 218 219 220 221 222Sermersheim Expires December 30, 2004 [Page 4] 223 224Internet-Draft Subordinate Subtree Search Scope for LDAP July 2004 225 226 227 Jim Sermersheim 228 jimse@novell.com 229 Usage: Extension 230 Specification: RFCXXXX 231 Author/Change Controller: IESG 232 Comments: none 233 234A.3 LDAP Descriptor Registrations 235 236 It is requested that IANA register upon Standards Action the LDAP 237 descriptors described in this document. The following registration 238 templates are given: 239 240 Subject: Request for LDAP Descriptor Registration 241 Descriptor (short name): subordScope 242 Object Identifier: IANA-ASSIGNED-OID.1 243 Person & email address to contact for further information: 244 Jim Sermersheim 245 jimse@novell.com 246 Usage: URL Extension 247 Specification: RFCXXXX 248 Author/Change Controller: IESG 249 Comments: none 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278Sermersheim Expires December 30, 2004 [Page 5] 279 280Internet-Draft Subordinate Subtree Search Scope for LDAP July 2004 281 282 283Intellectual Property Statement 284 285 The IETF takes no position regarding the validity or scope of any 286 Intellectual Property Rights or other rights that might be claimed to 287 pertain to the implementation or use of the technology described in 288 this document or the extent to which any license under such rights 289 might or might not be available; nor does it represent that it has 290 made any independent effort to identify any such rights. 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Please address the information to the IETF at 305 ietf-ipr@ietf.org. 306 307 308Disclaimer of Validity 309 310 This document and the information contained herein are provided on an 311 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 312 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 313 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 314 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 315 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 316 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 317 318 319Copyright Statement 320 321 Copyright (C) The Internet Society (2004). This document is subject 322 to the rights, licenses and restrictions contained in BCP 78, and 323 except as set forth therein, the authors retain all their rights. 324 325 326Acknowledgment 327 328 Funding for the RFC Editor function is currently provided by the 329 Internet Society. 330 331 332 333 334Sermersheim Expires December 30, 2004 [Page 6] 335 336