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'6' -- Possible downref: Non-RFC (?) normative reference: ref. '7' ** Downref: Normative reference to an Informational RFC: RFC 2753 (ref. '8') -- Possible downref: Non-RFC (?) normative reference: ref. '9' -- Possible downref: Non-RFC (?) normative reference: ref. '10' ** Obsolete normative reference: RFC 2256 (ref. '11') (Obsoleted by RFC 4510, RFC 4512, RFC 4517, RFC 4519, RFC 4523) Summary: 8 errors (**), 0 flaws (~~), 9 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Policy Framework Working Group J. Strassner 2 Internet-draft Intelliden Corporation 3 Category: Standards Track E. Ellesson 4 LongBoard, Inc. 5 B. Moore 6 IBM Corporation 7 R. Moats 8 Lemur Networks, Inc. 9 October 2001 10 Policy Core LDAP Schema 11 draft-ietf-policy-core-schema-12.txt 13 Status of this Memo 15 This document is an Internet-Draft and is in full conformance with all 16 provisions of Section 10 of RFC2026. 18 Internet-Drafts are working documents of the Internet Engineering Task 19 Force (IETF), its areas, and its working groups. Note that other 20 groups may also distribute working documents as Internet-Drafts. 22 Internet-Drafts are draft documents valid for a maximum of six months 23 and may be updated, replaced, or obsoleted by other documents at any 24 time. It is inappropriate to use Internet-Drafts as reference 25 material or to cite them other than as "work in progress." 27 The list of current Internet-Drafts can be accessed at 28 http://www.ietf.org/ietf/1id-abstracts.txt 30 The list of Internet-Draft Shadow Directories can be accessed at 31 http://www.ietf.org/shadow.html 33 Copyright Notice 35 Copyright (C) The Internet Society (2001). All Rights Reserved. 37 Abstract 39 This document defines a mapping of the Policy Core Information Model [1] 40 to a form that can be implemented in a directory that uses LDAP as its 41 access protocol. This model defines two hierarchies of object classes: 42 structural classes representing information for representing and 43 controlling policy data as specified in [1], and relationship classes 44 that indicate how instances of the structural classes are related to 45 each other. Classes are also added to the LDAP schema to improve the 46 performance of a client's interactions with an LDAP server when the 47 client is retrieving large amounts of policy-related information. These 48 classes exist only to optimize LDAP retrievals: there are no classes in 49 the information model that correspond to them. 51 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 52 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 53 document are to be interpreted as described in RFC 2119 [3]. 55 Table of Contents 57 1. Introduction 3 58 2. The Policy Core Information Model 4 59 3. Inheritance Hierarchy for the PCLS 5 60 4. General Discussion of Mapping the Information Model to LDAP 6 61 4.1. Summary of Class and Association Mappings 7 62 4.2. Usage of DIT Content and Structure Rules and Name Forms 9 63 4.3. Naming Attributes in the PCLS 10 64 4.4. Rule-Specific and Reusable Conditions and Actions 11 65 4.5. Location and Retrieval of Policy Objects in the Directory 15 66 4.5.1. Aliases and Other DIT-Optimization Techniques 17 67 5. Class Definitions 18 68 5.1. The Abstract Class "pcimPolicy" 19 69 5.2. The Three Policy Group Classes 20 70 5.3. The Three Policy Rule Classes 22 71 5.4. The Class pcimRuleConditionAssociation 28 72 5.5. The Class pcimRuleValidityAssociation 30 73 5.6. The Class pcimRuleActionAssociation 31 74 5.7. The Auxiliary Class pcimConditionAuxClass 33 75 5.8. The Auxiliary Class pcimTPCAuxClass 34 76 5.9. The Auxiliary Class pcimConditionVendorAuxClass 37 77 5.10. The Auxiliary Class pcimActionAuxClass 38 78 5.11. The Auxiliary Class pcimActionVendorAuxClass 38 79 5.12. The Class pcimPolicyInstance 40 80 5.13. The Auxiliary Class pcimElementAuxClass 41 81 5.14. The Three Policy Repository Classes 41 82 5.15. The Auxiliary Class pcimSubtreesPtrAuxClass 43 83 5.16. The Auxiliary Class pcimGroupContainmentAuxClass 44 84 5.17. The Auxiliary Class pcimRuleContainmentAuxClass 45 85 6. Extending the Classes Defined in This Document 47 86 6.1. Subclassing pcimConditionAuxClass and pcimActionAuxClass 47 87 6.2. Using the Vendor Policy Attributes 47 88 6.3. Using Time Validity Periods 47 89 7. Security Considerations 48 90 8. Intellectual Property 49 91 9. Acknowledgments 50 92 10. References 50 93 11. Authors' Addresses 51 94 12. Full Copyright Statement 52 95 13. Appendix: Constructing the Value of orderedCIMKeys 53 96 PLEASE NOTE: 97 OIDs for the schema elements in this document have not been assigned. 98 This note to be removed by the RFC editor before publication. All uses 99 of OIDs are indicated symbolically in brackets (for example, 100 is a placeholder that will be replaced by a real OID that is assigned by 101 IANA before publication. 103 1. Introduction 105 This document takes as its starting point the object-oriented 106 information model for representing information for representing and 107 controlling policy data as specified in [1]. LDAP implementers, please 108 note that the use of the term "policy" in this document does not refer 109 to the use of the term "policy" as defined in X.501 [5]. Rather, the use 110 of the term "policy" throughout this document is defined as follows: 112 Policy is defined as a set of rules to administer, manage, and 113 control access to network resources. 115 This work is currently under joint development in the IETF's Policy 116 Framework working group and in the Policy working group of the 117 Distributed Management Task Force (DMTF). This model defines two 118 hierarchies of object classes: structural classes representing policy 119 information and control of policies, and relationship classes that 120 indicate how instances of the structural classes are related to each 121 other. In general, both of these class hierarchies will need to be 122 mapped to a particular data store. 124 This draft defines the mapping of these information model classes to a 125 directory that uses LDAPv3 as its access protocol. Two types of 126 mappings are involved: 128 - For the structural classes in the information model, the mapping is 129 basically one-for-one: information model classes map to LDAP 130 classes, information model properties map to LDAP attributes. 132 - For the relationship classes in the information model, different 133 mappings are possible. In this document, the PCIM's relationship 134 classes and their properties are mapped in three ways: to LDAP 135 auxiliary classes, to attributes representing DN references, and 136 to superior-subordinate relationships in the Directory Information 137 Tree (DIT). 139 Implementations that use an LDAP directory as their policy repository 140 and want to implement policy information according to RFC3060 [1] SHALL 141 use the LDAP schema defined in this document, or a schema that 142 subclasses from the schema defined in this document. The use of the 143 information model defined in reference [1] as the starting point 144 enables the inheritance and the relationship class hierarchies to be 145 extensible, such that other types of policy repositories, such as 146 relational databases, can also use this information. 148 This document fits into the overall framework for representing, 149 deploying, and managing policies being developed by the Policy 150 Framework Working Group. 152 The LDAP schema described in this document uses the prefix "pcim" to 153 identify its classes and attributes. It consists of ten very general 154 classes: pcimPolicy (an abstract class), three policy group classes 155 (pcimGroup, pcimGroupAuxClass, and pcimGroupInstance), three policy rule 156 classes (pcimRule, pcimRuleAuxClass, and pcimRuleInstance), and three 157 special auxiliary classes (pcimConditionAuxClass, pcimTPCAuxClass, and 158 pcimActionAuxClass). (Note that the PolicyTimePeriodCondition auxiliary 159 class defined in [1] would normally have been named 160 pcimTimePeriodConditionAuxClass, but this name is too long for some 161 directories. Therefore, we have abbreviated this name to be 162 pcimTPCAuxClass). 164 The mapping for the PCIM classes pcimGroup and pcimRule is designed to 165 be as flexible as possible. An abstract superclass is defined that 166 contains all required properties, and then both an auxiliary class as 167 well as a structural class are derived from it. This provides maximum 168 flexibility for the developer. 170 The schema also contains two less general classes: 171 pcimConditionVendorAuxClass and pcimActionVendorAuxClass. To achieve 172 the mapping of the information model's relationships, the schema also 173 contains two auxiliary classes: pcimGroupContainmentAuxClass and 174 pcimRuleContainmentAuxClass. Capturing the distinction between rule- 175 specific and reusable policy conditions and policy actions introduces 176 seven other classes: pcimRuleConditionAssociation, 177 pcimRuleValidityAssociation, pcimRuleActionAssociation, 178 pcimPolicyInstance, and three policy repository classes (pcimRepository, 179 pcimRepositoryAuxClass, and pcimRepositoryInstance). Finally, the 180 schema includes two classes (pcimSubtreesPtrAuxClass and 181 pcimElementAuxClass) for optimizing LDAP retrievals. In all, the schema 182 contains 23 classes. 184 Within the context of this document, the term "PCLS" (Policy Core LDAP 185 Schema) is used to refer to the LDAP class definitions that this 186 document contains. The term "PCIM" refers to classes defined in [1]. 188 2. The Policy Core Information Model 190 This document contains an LDAP schema representing the classes defined 191 in the companion document "Policy Core Information Model -- Version 1 192 Specification" [1]. Other documents may subsequently be produced, with 193 mappings of this same PCIM to other storage technologies. Since the 194 detailed semantics of the PCIM classes appear only in [1], that document 195 is a prerequisite for reading and understanding this document. 197 3. Inheritance Hierarchy for the PCLS 199 The following diagram illustrates the class hierarchy for the LDAP 200 Classes defined in this document: 202 top 203 | 204 +--dlm1ManagedElement (abstract) 205 | | 206 | +--pcimPolicy (abstract) 207 | | | 208 | | +--pcimGroup (abstract) 209 | | | | 210 | | | +--pcimGroupAuxClass (auxiliary) 211 | | | | 212 | | | +--pcimGroupInstance (structural) 213 | | | 214 | | +--pcimRule (abstract) 215 | | | | 216 | | | +--pcimRuleAuxClass (auxiliary) 217 | | | | 218 | | | +--pcimRuleInstance (structural) 219 | | | 220 | | +--pcimRuleConditionAssociation (structural) 221 | | | 222 | | +--pcimRuleValidityAssociation (structural) 223 | | | 224 | | +--pcimRuleActionAssociation (structural) 225 | | | 226 | | +--pcimPolicyInstance (structural) 227 | | | 228 | | +--pcimElementAuxClass (auxiliary) 229 | | 230 | +--dlm1ManagedSystemElement (abstract) 231 | | 232 | +--dlm1LogicalElement (abstract) 233 | | 234 | +--dlm1System (abstract) 235 | | 236 | +--dlm1AdminDomain (abstract) 237 | | 238 | +--pcimRepository (abstract) 239 | | 240 | +--pcimRepositoryAuxClass (auxiliary) 241 | | 242 | +--pcimRepositoryInstance 243 (structural) 245 (continued on following page) 247 (continued from previous page) 249 top 250 | 251 +--pcimConditionAuxClass (auxiliary) 252 | | 253 | +---pcimTPCAuxClass (auxiliary) 254 | | 255 | +---pcimConditionVendorAuxClass (auxiliary) 256 | 257 +--pcimActionAuxClass (auxiliary) 258 | | 259 | +---pcimActionVendorAuxClass (auxiliary) 260 | 261 +--pcimSubtreesPtrAuxClass (auxiliary) 262 | 263 +--pcimGroupContainmentAuxClass (auxiliary) 264 | 265 +--pcimRuleContainmentAuxClass (auxiliary) 267 Figure 1. LDAP Class Inheritance Hierarchy for the PCLS 269 4. General Discussion of Mapping the Information Model to LDAP 271 The classes described in Section 5 below contain certain optimizations 272 for a directory that uses LDAP as its access protocol. One example of 273 this is the use of auxiliary classes to represent some of the 274 associations defined in the information model. Other data stores might 275 need to implement these associations differently. A second example is 276 the introduction of classes specifically designed to optimize retrieval 277 of large amounts of policy-related data from a directory. This section 278 discusses some general topics related to the mapping from the 279 information model to LDAP. 281 The remainder of this section will discuss the following topics. Section 282 4.1 will discuss the strategy used in mapping the classes and 283 associations defined in [1] to a form that can be represented in a 284 directory that uses LDAP as its access protocol. Section 4.2 discusses 285 DIT content and structure rules, as well as name forms. Section 4.3 286 describes the strategy used in defining naming attributes for the schema 287 described in Section 5 of this document. Section 4.4 defines the 288 strategy recommended for locating and retrieving PCIM-derived objects in 289 the directory. 291 4.1. Summary of Class and Association Mappings 293 Fifteen of the classes in the PCLS come directly from the nine 294 corresponding classes in the information model. Note that names of 295 classes begin with an upper case character in the information model 296 (although for CIM in particular, case is not significant in class and 297 property names), but with a lower case character in LDAP. This is 298 because although LDAP doesn't care, X.500 doesn't allow class names to 299 begin with an uppercase character. Note also that the prefix "pcim" is 300 used to identify these LDAP classes. 302 +---------------------------+-------------------------------+ 303 | Information Model | LDAP Class(es) | 304 +---------------------------+-------------------------------+ 305 +---------------------------+-------------------------------+ 306 | Policy | pcimPolicy | 307 +---------------------------+-------------------------------+ 308 | PolicyGroup | pcimGroup | 309 | | pcimGroupAuxClass | 310 | | pcimGroupInstance | 311 +---------------------------+-------------------------------+ 312 | PolicyRule | pcimRule | 313 | | pcimRuleAuxClass | 314 | | pcimRuleInstance | 315 +---------------------------+-------------------------------+ 316 | PolicyCondition | pcimConditionAuxClass | 317 +---------------------------+-------------------------------+ 318 | PolicyAction | pcimActionAuxClass | 319 +---------------------------+-------------------------------+ 320 | VendorPolicyCondition | pcimConditionVendorAuxClass | 321 +---------------------------+-------------------------------+ 322 | VendorPolicyAction | pcimActionVendorAuxClass | 323 +---------------------------+-------------------------------+ 324 | PolicyTimePeriodCondition | pcimTPCAuxClass | 325 +---------------------------+-------------------------------+ 326 | PolicyRepository | pcimRepository | 327 | | pcimRepositoryAuxClass | 328 | | pcimRepositoryInstance | 329 +---------------------------+-------------------------------+ 331 Figure 2. Mapping of Information Model Classes to LDAP 333 The associations in the information model map to attributes that 334 reference DNs (Distinguished Names) or to Directory Information Tree 335 (DIT) containment (i.e., superior-subordinate relationships) in LDAP. 336 Two of the attributes that reference DNs appear in auxiliary classes, 337 which allow each of them to represent several relationships from the 338 information model. 340 +----------------------------------+----------------------------------+ 341 | Information Model Association | LDAP Attribute / Class | 342 +-----------------------------------+---------------------------------+ 343 +-----------------------------------+---------------------------------+ 344 | PolicyGroupInPolicyGroup | pcimGroupsAuxContainedSet in | 345 | | pcimGroupContainmentAuxClass | 346 +-----------------------------------+---------------------------------+ 347 | PolicyRuleInPolicyGroup | pcimRulesAuxContainedSet in | 348 | | pcimRuleContainmentAuxClass | 349 +-----------------------------------+---------------------------------+ 350 | PolicyConditionInPolicyRule | DIT containment or | 351 | | pcimRuleConditionList in | 352 | | pcimRule or | 353 | | pcimConditionDN in | 354 | | pcimRuleConditionAssociation | 355 +-----------------------------------+---------------------------------+ 356 | PolicyActionInPolicyRule | DIT containment or | 357 | | pcimRuleActionList in | 358 | | pcimRule or | 359 | | pcimActionDN in | 360 | | pcimRuleActionAssociation | 361 +-----------------------------------+---------------------------------+ 362 | PolicyRuleValidityPeriod | pcimRuleValidityPeriodList | 363 | | in pcimRule or (if reusable) | 364 | | referenced through the | 365 | | pcimTimePeriodConditionDN in | 366 | | pcimRuleValidityAssociation | 367 +-----------------------------------+---------------------------------+ 368 | PolicyConditionInPolicyRepository | DIT containment | 369 +-----------------------------------+---------------------------------+ 370 | PolicyActionInPolicyRepository | DIT containment | 371 +-----------------------------------+---------------------------------+ 372 | PolicyRepositoryInPolicyRepository| DIT containment | 373 +-----------------------------------+---------------------------------+ 375 Figure 3. Mapping of Information Model Associations to LDAP 377 Of the remaining classes in the PCLS, two (pcimElementAuxClass and 378 pcimSubtreesPtrAuxClass) are included to make navigation through the DIT 379 and retrieval of the entries found there more efficient. This topic is 380 discussed in Section 4.5 below. 382 The remaining four classes in the PCLS, pcimRuleConditionAssociation, 383 pcimRuleValidityAssociation, pcimRuleActionAssociation, and 384 pcimPolicyInstance, are all involved with the representation of policy 385 conditions and policy actions in an LDAP directory. This topic is 386 discussed in Section 4.4 below. 388 4.2 Usage of DIT Content and Structure Rules and Name Forms 390 There are three powerful tools that can be used to help define schemata. 391 The first, DIT content rules, is a way of defining the content of an 392 entry for a structural object class. It can be used to specify the 393 following characteristics of the entry: 395 - additional mandatory attributes that the entries MUST contain 396 - additional optional attributes that the entries MAY contain 397 - the set of additional auxiliary object classes that these entries 398 MAY be members of 399 - any optional attributes from the structural and auxiliary object 400 class definitions that the entries MUST NOT contain. 402 DIT content rules are NOT mandatory for any structural object class. 404 A DIT structure rule, together with a name form, controls the placement 405 and naming of an entry within the scope of a subschema. Name forms 406 define which attribute type(s) MUST and MAY be used in forming the 407 Relative Distinguished Names (RDNs) of entries. DIT structure rules 408 specify which entries MAY be superior to other entries, and hence 409 control the way that RDNs are added together to make DNs. 411 A name form specifies the following: 413 - the structural object class of the entries named by this name form 414 - attributes that MUST be used in forming the RDNs of these entries 415 - attributes that MAY be used in forming the RDNs of these entries 416 - an object identifier to uniquely identify this name form 418 Note that name forms can only be specified for structural object 419 classes. However, every entry in the DIT must have a name form 420 controlling it. 422 Unfortunately, current LDAP servers vary quite a lot in their support of 423 these features. There are also three crucial implementation points that 424 must be followed. First, X.500 use of structure rules requires that a 425 structural object class with no superior structure rule be a subschema 426 administrative point. This is exactly NOT what we want for policy 427 information. Second, when an auxiliary class is subclassed, if a content 428 rule exists for the structural class that the auxiliary class refers to, 429 then that content rule needs to be augmented. Finally, most LDAP servers 430 unfortunately do not support inheritance of structure and content rules. 432 Given these concerns, DIT structure and content rules have been removed 433 from the PCLS. This is because, if included, they would be normative 434 references and would require OIDs. However, we don't want to lose the 435 insight gained in building the structure and content rules of the 436 previous version of the schema. Therefore, we describe where such rules 437 could be used in this schema, what they would control, and what their 438 effect would be. 440 4.3. Naming Attributes in the PCLS 442 Instances in a directory are identified by distinguished names (DNs), 443 which provide the same type of hierarchical organization that a file 444 system provides in a computer system. A distinguished name is a 445 sequence of RDNs. An RDN provides a unique identifier for an instance 446 within the context of its immediate superior, in the same way that a 447 filename provides a unique identifier for a file within the context of 448 the folder in which it resides. 450 To preserve maximum naming flexibility for policy administrators, three 451 optional (i.e., "MAY") naming attributes have been defined. They are: 453 - Each of the structural classes defined in this schema has its own 454 unique ("MAY") naming attribute. Since the naming attributes are 455 different, a policy administrator can, by using these attributes, 456 guarantee that there will be no name collisions between instances of 457 different classes, even if the same value is assigned to the 458 instances' respective naming attributes. 460 - The LDAP attribute cn (corresponding to X.500's commonName) is 461 included as a MAY attribute in the abstract class pcimPolicy, and 462 thus by inheritance in all of its subclasses. In X.500, commonName 463 typically functions as an RDN attribute, for naming instances of 464 many classes (e.g., X.500's person class). 466 - A special attribute is provided for implementations that expect to 467 map between native CIM and LDAP representations of policy 468 information. This attribute, called orderedCimKeys, is defined in 469 the class dlm1ManagedElement [10]. The value of this attribute is 470 derived algorithmically from values that are already present in a 471 CIM policy instance. See the appendix of this document for a 472 complete description of the algorithm. 474 Since any of these naming attributes MAY be used for naming an instance 475 of a PCLS class, implementations MUST be able to accommodate instances 476 named in any of these ways. 478 Note that it is recommended that two or more of these attributes SHOULD 479 NOT be used together to form a multi-part RDN, since support for multi- 480 part RDNs is limited among existing directory implementations. 482 4.4. Rule-Specific and Reusable Conditions and Actions 484 The PCIM [1] distinguishes between two types of policy conditions and 485 policy actions: ones associated with a single policy rule, and ones 486 that are reusable, in the sense that they may be associated with more 487 than one policy rule. While there is no inherent functional difference 488 between a rule-specific condition or action and a reusable one, there is 489 both a usage as well as an implementation difference between them. 491 Defining a condition or action as reusable vs. rule-specific reflects a 492 conscious decision on the part of the administrator in defining how they 493 are used. In addition, there are differences that reflect the difference 494 in implementing rule-specific vs. reusable policy conditions and actions 495 in how they are treated in a policy repository. The major implementation 496 differences between a rule-specific and a reusable condition or action 497 are delineated below: 499 1. It is natural for a rule-specific condition or action to be removed 500 from the policy repository at the same time the rule is. It is just 501 the opposite for reusable conditions and actions. This is because 502 the condition or action is conceptually attached to the rule in the 503 rule-specific case, whereas it is referenced (e.g., pointed at) in 504 the reusable case. The persistence of a pcimRepository instance is 505 independent of the persistence of a pcimRule instance. 506 2. Access permissions for a rule-specific condition or action are 507 usually identical to those for the rule itself. On the other hand, 508 access permissions of reusable conditions and actions must be 509 expressible without reference to a policy rule. 510 3. Rule-specific conditions and actions require fewer accesses, 511 because the conditions and actions are "attached" to the rule. In 512 contrast, reusable conditions and actions require more accesses, 513 because each condition or action that is reusable requires a 514 separate access. 515 4. Rule-specific conditions and actions are designed for use by a 516 single rule. As the number of rules that use the same rule-specific 517 condition increase, subtle problems are created (the most obvious 518 being how to keep the rule-specific conditions and actions updated 519 to reflect the same value). Reusable conditions and actions lend 520 themselves for use by multiple independent rules. 521 5. Reusable conditions and actions offer an optimization when multiple 522 rules are using the same condition or action. This is because the 523 reusable condition or action only needs be updated once, and by 524 virtue of DN reference, the policy rules will be automatically 525 updated. 527 The preceding paragraph does not contain an exhaustive list of the ways 528 in which reusable and rule-specific conditions should be treated 529 differently. Its purpose is merely to justify making a semantic 530 distinction between rule-specific and reusable, and then reflecting this 531 distinction in the policy repository itself. 533 When the policy repository is realized in an LDAP-accessible directory, 534 the distinction between rule-specific and reusable conditions and 535 actions is realized via placement of auxiliary classes and via DIT 536 containment. Figure 4 illustrates a policy rule Rule1 with one rule- 537 specific condition CA and one rule-specific action AB. 539 +-----+ 540 |Rule1| 541 | | 542 +-----|- -|-----+ 543 | +-----+ | 544 | * * | 545 | * * | 546 | **** **** | 547 | * * | 548 v * * v 549 +--------+ +--------+ 550 | CA+ca | | AB+ab | 551 +--------+ +--------+ 553 +------------------------------+ 554 |LEGEND: | 555 | ***** DIT containment | 556 | + auxiliary attachment | 557 | ----> DN reference | 558 +------------------------------+ 560 Figure 4. Rule-Specific Policy Conditions and Actions 562 Because the condition and action are specific to Rule1, the auxiliary 563 classes ca and ab that represent them are attached, respectively, to the 564 structural classes CA and AB. These structural classes represent not 565 the condition ca and action ab themselves, but rather the associations 566 between Rule1 and ca, and between Rule1 and ab. 568 As Figure 4 illustrates, Rule1 contains DN references to the structural 569 classes CA and AB that appear below it in the DIT. At first glance it 570 might appear that these DN references are unnecessary, since a subtree 571 search below Rule1 would find all of the structural classes representing 572 the associations between Rule1 and its conditions and actions. Relying 573 only on a subtree search, though, runs the risk of missing conditions or 574 actions that should have appeared in the subtree, but for some reason 575 did not, or of finding conditions or actions that were inadvertently 576 placed in the subtree, or that should have been removed from the 577 subtree, but for some reason were not. Implementation experience has 578 suggested that many (but not all) of these risks are eliminated. 580 However, it must be noted that this comes at a price. The use of DN 581 references, as shown in Figure 4 above, thwarts inheritance of access 582 control information as well as existence dependency information. It also 583 is subject to referential integrity considerations. Therefore, it is 584 being included as an option for the designer. 586 Figure 5 illustrates a second way of representing rule-specific 587 conditions and actions in an LDAP-accessible directory: attachment of 588 the auxiliary classes directly to the instance representing the policy 589 rule. When all of the conditions and actions are attached to a policy 590 rule in this way, the rule is termed a "simple" policy rule. When 591 conditions and actions are not attached directly to a policy rule, the 592 rule is termed a "complex" policy rule. 594 +-----------+ 595 |Rule1+ca+ab| 596 | | 597 +-----------+ 599 +------------------------------+ 600 |LEGEND: | 601 | + auxiliary attachment | 602 +------------------------------+ 604 Figure 5. A Simple Policy Rule 606 The simple/complex distinction for a policy rule is not all or nothing. 607 A policy rule may have its conditions attached to itself and its actions 608 attached to other entries, or it may have its actions attached to itself 609 and its conditions attached to other entries. However, it SHALL NOT have 610 either its conditions or its actions attached both to itself and to 611 other entries, with one exception: a policy rule may reference its 612 validity periods with the pcimRuleValidityPeriodList attribute, but have 613 its other conditions attached to itself. 615 The tradeoffs between simple and complex policy rules are between the 616 efficiency of simple rules and the flexibility and greater potential for 617 reuse of complex rules. With a simple policy rule, the semantic options 618 are limited: 620 - All conditions are ANDed together. This combination can be 621 represented in two ways in the DNF / CNF (please see [1] for 622 definitions of these terms) expressions characteristic of policy 623 conditions: as a DNF expression with a single AND group, or as 624 a CNF expression with multiple single-condition OR groups. The 625 first of these is arbitrarily chosen as the representation for 626 the ANDed conditions in a simple policy rule. 628 - If multiple actions are included, no order can be specified for 629 them. 631 If a policy administrator needs to combine conditions in some other way, 632 or if there is a set of actions that must be ordered, then the only 633 option is to use a complex policy rule. 635 Finally, Figure 6 illustrates the same policy rule Rule1, but this time 636 its condition and action are reusable. The association classes CA and 637 AB are still present, and they are still DIT contained under Rule1. But 638 rather than having the auxiliary classes ca and ab attached directly to 639 the association classes CA and AB, each now contains DN references to 640 other entries to which these auxiliary classes are attached. These 641 other entries, CIA and AIB, are DIT contained under RepositoryX, which 642 is an instance of the class pcimRepository. Because they are named 643 under an instance of pcimRepository, ca and ab are clearly identified as 644 reusable. 646 +-----+ +-------------+ 647 |Rule1| | RepositoryX | 648 +-|- -|--+ | | 649 | +-----+ | +-------------+ 650 | * * | * * 651 | * * | * * 652 | *** **** | * * 653 | * * v * * 654 | * +---+ * * 655 | * |AB | +------+ * 656 v * | -|-------->|AIB+ab| * 657 +---+ +---+ +------+ * 658 |CA | +------+ 659 | -|------------------------>|CIA+ca| 660 +---+ +------+ 662 +------------------------------+ 663 |LEGEND: | 664 | ***** DIT containment | 665 | + auxiliary attachment | 666 | ----> DN reference | 667 +------------------------------+ 669 Figure 6. Reusable Policy Conditions and Actions 671 The classes pcimConditionAuxClass and pcimActionAuxClass do not 672 themselves represent actual conditions and actions: these are 673 introduced in their subclasses. What pcimConditionAuxClass and 674 pcimActionAuxClass do introduce are the semantics of being a policy 675 condition or a policy action. These are the semantics that all the 676 subclasses of pcimConditionAuxClass and pcimActionAuxClass inherit. 677 Among these semantics are those of representing either a rule-specific 678 or a reusable policy condition or policy action. 680 In order to preserve the ability to represent a rule-specific or a 681 reusable condition or action, as well as a simple policy rule, all the 682 subclasses of pcimConditionAuxClass and pcimActionAuxClass MUST also be 683 auxiliary classes. 685 4.5. Location and Retrieval of Policy Objects in the Directory 687 When a PDP goes to an LDAP directory to retrieve the policy object 688 instances relevant to the PEPs it serves, it is faced with two related 689 problems: 691 - How does it locate and retrieve the directory entries that apply to 692 its PEPs? These entries may include instances of the PCLS classes, 693 instances of domain-specific subclasses of these classes, and 694 instances of other classes modeling such resources as user groups, 695 interfaces, and address ranges. 697 - How does it retrieve the directory entries it needs in an efficient 698 manner, so that retrieval of policy information from the directory 699 does not become a roadblock to scalability? There are two facets to 700 this efficiency: retrieving only the relevant directory entries, 701 and retrieving these entries using as few LDAP calls as possible. 703 The placement of objects in the Directory Information Tree (DIT) 704 involves considerations other than how the policy-related objects will 705 be retrieved by a PDP. Consequently, all that the PCLS can do is to 706 provide a "toolkit" of classes to assist the policy administrator as the 707 DIT is being designed and built. A PDP SHOULD be able to take advantage 708 of any tools that the policy administrator is able to build into the 709 DIT, but it MUST be able to use a less efficient means of retrieval if 710 that is all it has available to it. 712 The basic idea behind the LDAP optimization classes is a simple one: 713 make it possible for a PDP to retrieve all the policy-related objects it 714 needs, and only those objects, using as few LDAP calls as possible. An 715 important assumption underlying this approach is that the policy 716 administrator has sufficient control over the underlying DIT structure 717 to define subtrees for storing policy information. If the policy 718 administrator does not have this level of control over DIT structure, a 719 PDP can still retrieve the policy-related objects it needs individually. 720 But it will require more LDAP access operations to do the retrieval in 721 this way. Figure 7 illustrates how LDAP optimization is accomplished. 723 +-----+ 724 ---------------->| A | 725 DN reference to | | DN references to subtrees +---+ 726 starting object +-----+ +-------------------------->| C | 727 | o--+----+ +---+ +---+ 728 | o--+------------->| B | / \ 729 +-----+ +---+ / \ 730 / \ / \ / ... \ 731 / \ / \ 732 / \ / ... \ 734 Figure 7. Using the pcimSubtreesPtrAuxClass to Locate Policies 736 The PDP is configured initially with a DN reference to some entry in the 737 DIT. The structural class of this entry is not important; the PDP is 738 interested only in the pcimSubtreesPtrAuxClass attached to it. This 739 auxiliary class contains a multi-valued attribute with DN references to 740 objects that anchor subtrees containing policy-related objects of 741 interest to the PDP. Since pcimSubtreesPtrAuxClass is an auxiliary 742 class, it can be attached to an entry that the PDP would need to access 743 anyway - perhaps an entry containing initial configuration settings for 744 the PDP, or for a PEP that uses the PDP. 746 Once it has retrieved the DN references, the PDP will direct to each of 747 the objects identified by them an LDAP request that all entries in its 748 subtree be evaluated against the selection criteria specified in the 749 request. The LDAP-enabled directory then returns all entries in that 750 subtree that satisfy the specified criteria. 752 The selection criteria always specify that object class="pcimPolicy". 753 Since all classes representing policy rules, policy conditions, and 754 policy actions, both in the PCLS and in any domain-specific schema 755 derived from it, are subclasses of the abstract class policy, this 756 criterion evaluates to TRUE for all instances of these classes. To 757 accommodate special cases where a PDP needs to retrieve objects that are 758 not inherently policy-related (for example, an IP address range object 759 referenced by a subclass of pcimActionAuxClass representing the DHCP 760 action "assign from this address range), the auxiliary class 761 pcimElementAuxClass can be used to "tag" an entry, so that it will be 762 found by the selection criterion "object class=pcimPolicy". 764 The approach described in the preceding paragraph will not work for 765 certain directory implementations, because these implementations do not 766 support matching of auxiliary classes in the objectClass attribute. For 767 environments where these implementations are expected to be present, the 768 "tagging" of entries as relevant to policy can be accomplished by 769 inserting the special value "POLICY" into the list of values contained 770 in the pcimKeywords attribute (provided by the pcimPolicy class). 772 If a PDP needs only a subset of the policy-related objects in the 773 indicated subtrees, then it can be configured with additional selection 774 criteria based on the pcimKeywords attribute defined in the pcimPolicy 775 class. This attribute supports both standardized and administrator- 776 defined values. For example, a PDP could be configured to request only 777 those policy-related objects containing the keywords "DHCP" and "Eastern 778 US". 780 To optimize what is expected to be a typical case, the initial request 781 from the client includes not only the object to which its "seed" DN 782 references, but also the subtree contained under this object. The 783 filter for searching this subtree is whatever the client is going to use 784 later to search the other subtrees: object class="pcimPolicy" or the 785 presence of the keyword "POLICY", and/or presence of a more specific 786 value of pcimKeywords (e.g., "QoS Edge Policy"). 788 Returning to the example in Figure 7, we see that in the best case, a 789 PDP can get all the policy-related objects it needs, and only those 790 objects, with exactly three LDAP requests: one to its starting object A 791 to get the references to B and C, as well as the policy-related objects 792 it needs from the subtree under A, and then one each to B and C to get 793 all the policy-related objects that pass the selection criteria with 794 which it was configured. Once it has retrieved all of these objects, 795 the PDP can then traverse their various DN references locally to 796 understand the semantic relationships among them. The PDP should also 797 be prepared to find a reference to another subtree attached to any of 798 the objects it retrieves, and to follow this reference first, before it 799 follows any of the semantically significant references it has received. 800 This recursion permits a structured approach to identifying related 801 policies. In Figure 7, for example, if the subtree under B includes 802 departmental policies and the one under C includes divisional policies, 803 then there might be a reference from the subtree under C to an object D 804 that roots the subtree of corporate-level policies. 806 A PDP SHOULD understand the pcimSubtreesPtrAuxClass class, SHOULD be 807 capable of retrieving and processing the entries in the subtrees it 808 references, and SHOULD be capable of doing all of this recursively. The 809 same requirements apply to any other entity needing to retrieve policy 810 information from the directory. Thus, a Policy Management Tool that 811 retrieves policy entries from the directory in order to perform 812 validation and conflict detection SHOULD also understand and be capable 813 of using the pcimSubtreesPtrAuxClass. All of these requirements are 814 "SHOULD"s rather than "MUST"s because an LDAP client that doesn't 815 implement them can still access and retrieve the directory entries it 816 needs. The process of doing so will just be less efficient than it 817 would have been if the client had implemented these optimizations. 819 When it is serving as a tool for creating policy entries in the 820 directory, a Policy Management Tool SHOULD support creation of 821 pcimSubtreesPtrAuxClass entries and their references to object 822 instances. 824 4.5.1. Aliases and Other DIT-Optimization Techniques 826 Additional flexibility in DIT structure is available to the policy 827 administrator via LDAP aliasing and other techniques. Previous versions 828 of this document have used aliases. However, because aliases are 829 experimental, the use of aliases has been removed from this version of 830 this document. This is because the IETF has yet to produce a 831 specification on how aliases are represented in the directory or how 832 server implementations are to process aliases. 834 5. Class Definitions 836 The semantics for the policy information classes that are to be mapped 837 directly from the information model to an LDAP representation are 838 detailed in [1]. Consequently, all that this document presents for 839 these classes is the specification for how to do the mapping from the 840 information model (which is independent of repository type and access 841 protocol) to a form that can be accessed using LDAP. Remember that some 842 new classes needed to be created (that were not part of [1]) to 843 implement the LDAP mapping. These new LDAP-only classes are fully 844 documented in this document. 846 The formal language for specifying the classes, attributes, and DIT 847 structure and content rules is that defined in reference [2]. If your 848 implementation does not support auxiliary class inheritance, you will 849 have to list auxiliary classes in content rules explicitly or define 850 them in another (implementation-specific) way. 852 The following notes apply to this section in its entirety. 854 Note 1: in the following definitions, the class and attribute 855 definitions follow RFC2252 [2] but they are line-wrapped to enhance 856 human readability. 858 Note 2: where applicable, the possibilities for specifying DIT structure 859 and content rules are noted. However, care must be taken in specifying 860 DIT structure rules. This is because X.501 [5] states that an entry may 861 only exist in the DIT as a subordinate to another superior entry (the 862 superior) if a DIT structure rule exists in the governing subschema 863 which: 865 1) indicates a name form for the structural object class of the 866 subordinate entry, and 867 2) either includes the entry's superior structure rule as a possible 868 superior structure rule, or 869 3) does not specify a superior structure rule. 871 If this last case (3) applies, then the entry is defined to be a 872 subschema administrative point. This is not what is desired. Therefore, 873 care must be taken in defining structure rules, and in particular, they 874 must be locally augmented. 876 Note 3: Wherever possible, both an equality and a substring matching 877 rule are defined for a particular attribute (as well as an ordering 878 match rule to enable sorting of matching results). This provides two 879 different choices for the developer for maximum flexibility. 881 For example, consider the pcimRoles attribute (section 5.3). Suppose 882 that a PEP has reported that it is interested in pcimRules for three 883 roles R1, R2, and R3. If the goal is to minimize queries, then the PDP 884 can supply three substring filters containing the three role names. 886 These queries will return all of the pcimRules that apply to the PEP, 887 but they may also get some that do not apply (e.g., ones that contain 888 one of the roles R1, R2, or R3 and one or more other roles present in a 889 role-combination [1]). 891 Another strategy would be for the PDP to use only equality filters. This 892 approach eliminates the extraneous replies, but it requires the PDP to 893 explicitly build the desired role-combinations itself. It also requires 894 extra queries. Note that this approach is practical only because the 895 role names in a role combination are required to appear in alphabetical 896 order. 898 Note 4: in the following definitions, OIDs are indicated by placeholders 899 of the form: , where xx can be "oc" for "object class" or 900 "at" for "attribute". These placeholder values will be replaced with 901 real OIDs assigned by the RFC Editor from IANA before publication. This 902 note (only) to be removed by the RFC editor before publication. 904 5.1. The Abstract Class pcimPolicy 906 The abstract class pcimPolicy is a direct mapping of the abstract class 907 Policy from the PCIM. The class value "pcimPolicy" is also used as the 908 mechanism for identifying policy-related instances in the Directory 909 Information Tree. An instance of any class may be "tagged" with this 910 class value by attaching to it the auxiliary class pcimElementAuxClass. 912 The class definition is as follows: 914 ( NAME 'pcimPolicy' 915 DESC 'An abstract class that is the base class for all classes 916 that describe policy-related instances.' 917 SUP dlm1ManagedElement 918 ABSTRACT 919 MAY ( cn $ dlmCaption $ dlmDescription $ orderedCimKeys $ 920 pcimKeywords ) 921 ) 923 The attribute cn is defined in RFC 2256 [11]. The dlmCaption, 924 dlmDescription, and orderedCimKeys attributes are defined in [10]. 926 The pcimKeywords attribute is a multi-valued attribute that contains a 927 set of keywords to assist directory clients in locating the policy 928 objects identified by these keywords. It is defined as follows: 930 ( NAME 'pcimKeywords' 931 DESC 'A set of keywords to assist directory clients in 932 locating the policy objects applicable to them.' 933 EQUALITY caseIgnoreMatch 934 ORDERING caseIgnoreOrderingMatch 935 SUBSTR caseIgnoreSubstringsMatch 936 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 937 ) 939 5.2. The Three Policy Group Classes 941 PCIM [1] defines the PolicyGroup class to serve as a generalized 942 aggregation mechanism, enabling PolicyRules and/or PolicyGroups to be 943 aggregated together. PCLS maps this class into three LDAP classes, 944 called pcimGroup, pcimGroupAuxClass, and pcimGroupInstance. This is done 945 in order to provide maximum flexibility for the DIT designer. 947 The class definitions for the three policy group classes are listed 948 below. These class definitions do not include attributes to realize the 949 PolicyRuleInPolicyGroup and PolicyGroupInPolicyGroup associations from 950 the PCIM. This is because a pcimGroup object refers to instances of 951 pcimGroup and pcimRule via, respectively, the attribute 952 pcimGroupsAuxContainedSet in the pcimGroupContainmentAuxClass object 953 class and the attribute pcimRulesAuxContainedSet in the 954 pcimRuleContainmentAuxClass object class. 956 To maximize flexibility, the pcimGroup class is defined as abstract. The 957 subclass pcimGroupAuxClass provides for auxiliary attachment to 958 another entry, while the structural subclass pcimGroupInstance is 959 available to represent a policy group as a standalone entry. 961 The class definitions are as follows. First, the definition of the 962 abstract class pcimGroup: 964 ( NAME 'pcimGroup' 965 DESC 'A container for a set of related pcimRules and/or 966 a set of related pcimGroups.' 967 SUP pcimPolicy 968 ABSTRACT 969 MAY ( pcimGroupName ) 970 ) 972 The one attribute of pcimGroup is pcimGroupName. This attribute is used 973 to define a user-friendly name of this policy group, and may be used as 974 a naming attribute if desired. It is defined as follows: 976 ( NAME 'pcimGroupName' 977 DESC 'The user-friendly name of this policy group.' 978 EQUALITY caseIgnoreMatch 979 ORDERING caseIgnoreOrderingMatch 980 SUBSTR caseIgnoreSubstringsMatch 981 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 982 SINGLE-VALUE 983 ) 985 The two subclasses of pcimGroup are defined as follows. The class 986 pcimGroupAuxClass is an auxiliary class that can be used to collect a 987 set of related pcimRule and/or pcimGroup classes. It is defined as 988 follows: 990 ( NAME 'pcimGroupAuxClass' 991 DESC 'An auxiliary class that collects a set of related 992 pcimRule and/or pcimGroup entries.' 993 SUP pcimGroup 994 AUXILIARY 995 ) 997 The class pcimGroupInstance is a structural class that can be used to 998 collect a set of related pcimRule and/or pcimGroup classes. It is 999 defined as follows: 1001 ( NAME 'pcimGroupInstance' 1002 DESC 'A structural class that collects a set of related 1003 pcimRule and/or pcimGroup entries.' 1004 SUP pcimGroup 1005 STRUCTURAL 1006 ) 1008 A DIT content rule could be written to enable an instance of 1009 pcimGroupInstance to have attached to it either references to one or 1010 more policy groups (using pcimGroupContainmentAuxClass) or references to 1011 one or more policy rules (using pcimRuleContainmentAuxClass). This would 1012 be used to formalize the semantics of the PolicyGroup class [1]. Since 1013 these semantics do not include specifying any properties of the 1014 PolicyGroup class, the content rule would not need to specify any 1015 attributes. 1017 Similarly, three separate DIT structure rules could be written, each of 1018 which would refer to a specific name form that identified one of the 1019 three possible naming attributes (i.e., pcimGroupName, cn, and 1020 orderedCIMKeys) for the pcimGroup object class. This structure rule 1021 SHOULD include a superiorStructureRule (see Note 2 at the beginning of 1022 section 5). The three name forms referenced by the three structure rules 1023 would each define one of the three naming attributes. 1025 5.3. The Three Policy Rule Classes 1027 The information model defines a PolicyRule class to represent the "If 1028 Condition then Action" semantics associated with processing policy 1029 information. For maximum flexibility, the PCLS maps this class into 1030 three LDAP classes. 1032 To maximize flexibility, the pcimRule class is defined as abstract. The 1033 subclass pcimRuleAuxClass provides for auxiliary attachment to another 1034 entry, while the structural subclass pcimRuleInstance is available to 1035 represent a policy rule as a standalone entry. 1037 The conditions and actions associated with a policy rule are modeled, 1038 respectively, with auxiliary subclasses of the auxiliary classes 1039 pcimConditionAuxClass and pcimActionAuxClass. Each of these auxiliary 1040 subclasses is attached to an instance of one of three structural 1041 classes. A subclass of pcimConditionAuxClass is attached to an instance 1042 of pcimRuleInstance, to an instance of pcimRuleConditionAssociation, or 1043 to an instance of pcimPolicyInstance. Similarly, a subclass of 1044 pcimActionAuxClass is attached to an instance of pcimRuleInstance, to an 1045 instance of pcimRuleActionAssociation, or to an instance of 1046 pcimPolicyInstance. 1048 The pcimRuleValidityPeriodList attribute (defined below) realizes the 1049 PolicyRuleValidityPeriod association defined in the PCIM. Since this 1050 association has no additional properties besides those that tie the 1051 association to its associated objects, this association can be realized 1052 by simply using an attribute. Thus, the pcimRuleValidityPeriodList 1053 attribute is simply a multi-valued attribute that provides an unordered 1054 set of DN references to one or more instances of the pcimTPCAuxClass, 1055 indicating when the policy rule is scheduled to be active and when it is 1056 scheduled to be inactive. A policy rule is scheduled to be active if it 1057 is active according to AT LEAST ONE of the pcimTPCAuxClass instances 1058 referenced by this attribute. 1060 The PolicyConditionInPolicyRule and PolicyActionInPolicyRule 1061 associations, however, do have additional attributes. The association 1062 PolicyActionInPolicyRule defines an integer attribute to sequence the 1063 actions, and the association PolicyConditionInPolicyRule has both an 1064 integer attribute to group the condition terms as well as a Boolean 1065 property to specify whether a condition is to be negated. 1067 In the PCLS, these additional association attributes are represented as 1068 attributes of two classes introduced specifically to model these 1069 associations. These classes are the pcimRuleConditionAssociation class 1070 and the pcimRuleActionAssociation class, which are defined in Sections 1071 5.4 and 5.5, respectively. Thus, they do not appear as attributes of 1072 the class pcimRule. Instead, the pcimRuleConditionList and 1073 pcimRuleActionList attributes can be used to reference these classes. 1075 The class definitions for the three pcimRule classes are as follows. 1077 The abstract class pcimRule is a base class for representing the "If 1078 Condition then Action" semantics associated with a policy rule. It is 1079 defined as follows: 1081 ( NAME 'pcimRule' 1082 DESC 'The base class for representing the "If Condition 1083 then Action" semantics associated with a policy rule.' 1084 SUP pcimPolicy 1085 ABSTRACT 1086 MAY ( pcimRuleName $ pcimRuleEnabled $ 1087 pcimRuleConditionListType $ pcimRuleConditionList $ 1088 pcimRuleActionList $ pcimRuleValidityPeriodList $ 1089 pcimRuleUsage $ pcimRulePriority $ 1090 pcimRuleMandatory $ pcimRuleSequencedActions $ 1091 pcimRoles ) 1092 ) 1094 The PCIM [1] defines seven properties for the PolicyRule class. The PCLS 1095 defines eleven attributes for the pcimRule class, which is the LDAP 1096 equivalent of the PolicyRule class. Of these eleven attributes, seven 1097 are mapped directly from corresponding properties in PCIM's PolicyRule 1098 class. The remaining four attributes are a class-specific optional 1099 naming attribute, and three attributes used to realize the three 1100 associations that the pcimRule class participates in. 1102 The pcimRuleName attribute is used as a user-friendly name of this 1103 policy rule, and can also serve as the class-specific optional naming 1104 attribute. It is defined as follows: 1106 ( NAME 'pcimRuleName' 1107 DESC 'The user-friendly name of this policy rule.' 1108 EQUALITY caseIgnoreMatch 1109 ORDERING caseIgnoreOrderingMatch 1110 SUBSTR caseIgnoreSubstringsMatch 1111 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1112 SINGLE-VALUE 1113 ) 1115 The pcimRuleEnabled attribute is an integer enumeration indicating 1116 whether a policy rule is administratively enabled (value=1), 1117 administratively disabled (value=2), or enabled for debug (value=3). It 1118 is defined as follows: 1120 ( NAME 'pcimRuleEnabled' 1121 DESC 'An integer indicating whether a policy rule is 1122 administratively enabled (value=1), disabled 1123 (value=2), or enabled for debug (value=3).' 1124 EQUALITY integerMatch 1125 ORDERING integerOrderingMatch 1126 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1127 SINGLE-VALUE 1128 ) 1130 Note: All other values for the pcimRuleEnabled attribute are considered 1131 errors, and the administrator SHOULD disable this rule if an invalid 1132 value is found. 1134 The pcimRuleConditionListType attribute is used to indicate whether the 1135 list of policy conditions associated with this policy rule is in 1136 disjunctive normal form (DNF, value=1) or conjunctive normal form (CNF, 1137 value=2). It is defined as follows: 1139 ( NAME 'pcimRuleConditionListType' 1140 DESC 'A value of 1 means that this policy rule is in 1141 disjunctive normal form; a value of 2 means that this 1142 policy rule is in conjunctive normal form.' 1143 EQUALITY integerMatch 1144 ORDERING integerOrderingMatch 1145 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1146 SINGLE-VALUE 1147 ) 1149 Note: any other value than 1 or 2 for the pcimRuleConditionListType 1150 attribute is considered an error. Administrators SHOULD disable the rule 1151 if an invalid value is found, since it is unclear how to structure the 1152 condition list. 1154 The pcimRuleConditionList attribute is a multi-valued attribute that is 1155 used to realize the policyRuleInPolicyCondition association defined in 1156 [1]. It contains a set of DNs of pcimRuleConditionAssociation entries 1157 representing associations between this policy rule and its conditions. 1158 No order is implied. It is defined as follows: 1160 ( NAME 'pcimRuleConditionList' 1161 DESC 'Unordered set of DNs of pcimRuleConditionAssociation 1162 entries representing associations between this policy 1163 rule and its conditions.' 1164 EQUALITY distinguishedNameMatch 1165 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1166 ) 1168 The pcimRuleActionList attribute is a multi-valued attribute that is 1169 used to realize the policyRuleInPolicyAction association defined in [1]. 1170 It contains a set of DNs of pcimRuleActionAssociation entries 1171 representing associations between this policy rule and its actions. No 1172 order is implied. It is defined as follows: 1174 ( NAME 'pcimRuleActionList' 1175 DESC 'Unordered set of DNs of pcimRuleActionAssociation 1176 entries representing associations between this policy 1177 rule and its actions.' 1178 EQUALITY distinguishedNameMatch 1179 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1180 ) 1182 The pcimRuleValidityPeriodList attribute is a multi-valued attribute 1183 that is used to realize the pcimRuleValidityPeriod association that is 1184 defined in [1]. It contains a set of DNs of pcimRuleValidityAssociation 1185 entries that determine when the pcimRule is scheduled to be active or 1186 inactive. No order is implied. It is defined as follows: 1188 ( NAME 'pcimRuleValidityPeriodList' 1189 DESC 'Unordered set of DNs of pcimRuleValidityAssociation 1190 entries that determine when the pcimRule is scheduled 1191 to be active or inactive.' 1192 EQUALITY distinguishedNameMatch 1193 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1194 ) 1196 The pcimRuleUsage attribute is a free-form sting providing guidelines on 1197 how this policy should be used. It is defined as follows: 1199 ( NAME 'pcimRuleUsage' 1200 DESC 'This attribute is a free-form sting providing 1201 guidelines on how this policy should be used.' 1202 EQUALITY caseIgnoreMatch 1203 ORDERING caseIgnoreOrderingMatch 1204 SUBSTR caseIgnoreSubstringsMatch 1205 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1206 SINGLE-VALUE 1207 ) 1209 The pcimRulePriority attribute is a non-negative integer that is used to 1210 prioritize this pcimRule relative to other pcimRules. A larger value 1211 indicates a higher priority. It is defined as follows: 1213 ( NAME 'pcimRulePriority' 1214 DESC 'A non-negative integer for prioritizing this 1215 pcimRule relative to other pcimRules. A larger 1216 value indicates a higher priority.' 1217 EQUALITY integerMatch 1218 ORDERING integerOrderingMatch 1219 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1220 SINGLE-VALUE 1221 ) 1223 Note: if the value of the pcimRulePriority field is 0, then it SHOULD be 1224 treated as "don't care". On the other hand, if the value is negative, 1225 then it SHOULD be treated as an error and the rule SHOULD be disabled. 1227 The pcimRuleMandatory attribute is a Boolean attribute that, if TRUE, 1228 indicates that for this policy rule, the evaluation of its conditions 1229 and execution of its actions (if the condition is satisfied) is 1230 required. If it is FALSE, then the evaluation of its conditions and 1231 execution of its actions (if the condition is satisfied) is not 1232 required. This attribute is defined as follows: 1234 ( NAME 'pcimRuleMandatory' 1235 DESC 'If TRUE, indicates that for this policy rule, the 1236 evaluation of its conditions and execution of its 1237 actions (if the condition is satisfied) is required.' 1238 EQUALITY booleanMatch 1239 SYNTAX 1.3.6.1.4.1.1466.115.121.1.7 1240 SINGLE-VALUE 1241 ) 1243 The pcimRuleSequencedActions attribute is an integer enumeration that is 1244 used to indicate that the ordering of actions defined by the 1245 pcimActionOrder attribute is either mandatory(value=1), 1246 recommended(value=2), or dontCare(value=3). It is defined as follows: 1248 ( NAME 'pcimRuleSequencedActions' 1249 DESC 'An integer enumeration indicating that the ordering of 1250 actions defined by the pcimActionOrder attribute is 1251 mandatory(1), recommended(2), or dontCare(3).' 1252 EQUALITY integerMatch 1253 ORDERING integerOrderingMatch 1254 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1255 SINGLE-VALUE 1256 ) 1258 Note: if the value of pcimRulesSequencedActions field is not one of 1259 these three values, then the administrator SHOULD treat this as an error 1260 and disable the rule. 1262 The pcimRoles attribute represents the policyRoles property of [1]. Each 1263 value of this attribute represents a role-combination, which is a string 1264 of the form: 1265 [&&]* 1266 where the individual role names appear in alphabetical order according 1267 to the collating sequence for UCS-2. This attribute is defined as 1268 follows: 1270 ( NAME 'pcimRoles' 1271 DESC 'Each value of this attribute represents a role- 1272 combination.' 1273 EQUALITY caseIgnoreMatch 1274 ORDERING caseIgnoreOrderingMatch 1275 SUBSTR caseIgnoreSubstringsMatch 1276 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1277 ) 1279 Note: if the value of the pcimRoles attribute does not conform to the 1280 format "[&&]*" (see Section 6.3.7 of [1]), then this 1281 attribute is malformed and its policy rule SHOULD be disabled. 1283 The two subclasses of the pcimRule class are defined as follows. First, 1284 the pcimRuleAuxClass is an auxiliary class for representing the "If 1285 Condition then Action" semantics associated with a policy rule. Its 1286 class definition is as follows: 1288 ( NAME 'pcimRuleAuxClass' 1289 DESC 'An auxiliary class for representing the "If Condition 1290 then Action" semantics associated with a policy rule.' 1291 SUP pcimRule 1292 AUXILIARY 1293 ) 1295 The pcimRuleInstance is a structural class for representing the "If 1296 Condition then Action" semantics associated with a policy rule. Its 1297 class definition is as follows: 1299 ( NAME 'pcimRuleInstance' 1300 DESC 'A structural class for representing the "If Condition 1301 then Action" semantics associated with a policy rule.' 1302 SUP pcimRule 1303 STRUCTURAL 1304 ) 1306 A DIT content rule could be written to enable an instance of 1307 pcimRuleInstance to have attached to it either references to one or more 1308 policy conditions (using pcimConditionAuxClass) or references to one or 1309 more policy actions (using pcimActionAuxClass). This would be used to 1310 formalize the semantics of the PolicyRule class [1]. Since these 1311 semantics do not include specifying any properties of the PolicyRule 1312 class, the content rule would not need to specify any attributes. 1314 Similarly, three separate DIT structure rules could be written, each of 1315 which would refer to a specific name form that identified one of its 1316 three possible naming attributes (i.e., pcimRuleName, cn, and 1317 orderedCIMKeys). This structure rule SHOULD include a 1318 superiorStructureRule (see Note 2 at the beginning of section 5). The 1319 three name forms referenced by the three structure rules would each 1320 define one of the three naming attributes. 1322 5.4. The Class pcimRuleConditionAssociation 1324 This class contains attributes to represent the properties of the PCIM's 1325 PolicyConditionInPolicyRule association. Instances of this class are 1326 related to an instance of pcimRule via DIT containment. The policy 1327 conditions themselves are represented by auxiliary subclasses of the 1328 auxiliary class pcimConditionAuxClass. These auxiliary classes are 1329 attached directly to instances of pcimRuleConditionAssociation for rule- 1330 specific policy conditions. For a reusable policy condition, the 1331 policyCondition auxiliary subclass is attached to an instance of the 1332 class pcimPolicyInstance (which is presumably associated with a 1333 pcimRepository by DIT containment), and the policyConditionDN attribute 1334 (of this class) is used to reference the reusable policyCondition 1335 instance. 1337 The class definition is as follows: 1339 ( NAME 'pcimRuleConditionAssociation' 1340 DESC 'This class contains attributes characterizing the 1341 relationship between a policy rule and one of its 1342 policy conditions.' 1343 SUP pcimPolicy 1344 MUST ( pcimConditionGroupNumber $ pcimConditionNegated ) 1345 MAY ( pcimConditionName $ pcimConditionDN ) 1346 ) 1348 The attributes of this class are defined as follows. 1350 The pcimConditionGroupNumber attribute is a non-negative integer. It is 1351 used to identify the group to which the condition referenced by this 1352 association is assigned. This attribute is defined as follows: 1354 ( 1355 NAME 'pcimConditionGroupNumber' 1356 DESC 'The number of the group to which a policy condition 1357 belongs. This is used to form the DNF or CNF 1358 expression associated with a policy rule.' 1359 EQUALITY integerMatch 1360 ORDERING integerOrderingMatch 1361 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1362 SINGLE-VALUE 1363 ) 1365 Note that this number is non-negative. A negative value for this 1366 attribute is invalid, and any policy rule that refers to this entry 1367 SHOULD be disabled. 1369 The pcimConditionNegated attribute is a Boolean attribute that indicates 1370 whether this policy condition is to be negated or not. If it is TRUE 1371 (FALSE), it indicates that a policy condition IS (IS NOT) negated in the 1372 DNF or CNF expression associated with a policy rule. This attribute is 1373 defined as follows: 1375 ( 1376 NAME 'pcimConditionNegated' 1377 DESC 'If TRUE (FALSE), it indicates that a policy condition 1378 IS (IS NOT) negated in the DNF or CNF expression 1379 associated with a policy rule.' 1380 EQUALITY booleanMatch 1381 SYNTAX 1.3.6.1.4.1.1466.115.121.1.7 1382 SINGLE-VALUE 1383 ) 1385 The pcimConditionName is a user-friendly name for identifying this 1386 policy condition, and may be used as a naming attribute if desired. This 1387 attribute is defined as follows: 1389 ( 1390 NAME 'pcimConditionName' 1391 DESC 'A user-friendly name for a policy condition.' 1392 EQUALITY caseIgnoreMatch 1393 ORDERING caseIgnoreOrderingMatch 1394 SUBSTR caseIgnoreSubstringsMatch 1395 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1396 SINGLE-VALUE 1397 ) 1399 The pcimConditionDN attribute is a DN that references an instance of a 1400 reusable policy condition. This attribute is defined as follows: 1402 ( 1403 NAME 'pcimConditionDN' 1404 DESC 'A DN that references an instance of a reusable policy 1405 condition.' 1406 EQUALITY distinguishedNameMatch 1407 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1408 SINGLE-VALUE 1409 ) 1411 A DIT content rule could be written to enable an instance of 1412 pcimRuleConditionAssociation to have attached to it an instance of the 1413 auxiliary class pcimConditionAuxClass, or one of its subclasses. This 1414 would be used to formalize the semantics of the 1415 PolicyConditionInPolicyRule association. Specifically, this would be 1416 used to represent a rule-specific policy condition [1]. 1418 Similarly, three separate DIT structure rules could be written. Each of 1419 these DIT structure rules would refer to a specific name form that 1420 defined two important semantics. First, each name form would identify 1421 one of the three possible naming attributes (i.e., pcimConditionName, 1422 cn, and orderedCIMKeys) for the pcimRuleConditionAssociation object 1423 class. Second, each name form would require that an instance of the 1424 pcimRuleConditionAssociation class have as its superior an instance of 1425 the pcimRule class. This structure rule SHOULD also include a 1426 superiorStructureRule (see Note 2 at the beginning of section 5). 1428 5.5. The Class pcimRuleValidityAssociation 1430 The policyRuleValidityPeriod aggregation is mapped to the PCLS 1431 pcimRuleValidityAssociation class. This class represents the scheduled 1432 activation and deactivation of a policy rule by binding the definition 1433 of times that the policy is active to the policy rule itself. The 1434 "scheduled" times are either identified through an attached auxiliary 1435 class pcimTPCAuxClass, or are referenced through its 1436 pcimTimePeriodConditionDN attribute. 1438 This class is defined as follows: 1440 ( NAME 'pcimRuleValidityAssociation' 1441 DESC 'This defines the scheduled activation or deactivation 1442 of a policy rule.' 1443 SUP pcimPolicy 1444 STRUCTURAL 1445 MAY ( pcimValidityConditionName $ pcimTimePeriodConditionDN ) 1446 ) 1448 The attributes of this class are defined as follows: 1450 The pcimValidityConditionName attribute is used to define a user- 1451 friendly name of this condition, and may be used as a naming attribute 1452 if desired. This attribute is defined as follows: 1454 ( 1455 NAME 'pcimValidityConditionName' 1456 DESC 'A user-friendly name for identifying an instance of 1457 a pcimRuleValidityAssociation entry.' 1458 EQUALITY caseIgnoreMatch 1459 ORDERING caseIgnoreOrderingMatch 1460 SUBSTR caseIgnoreSubstringsMatch 1461 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1462 SINGLE-VALUE 1463 ) 1465 The pcimTimePeriodConditionDN attribute is a DN that references a 1466 reusable time period condition. It is defined as follows: 1468 ( 1469 NAME 'pcimTimePeriodConditionDN' 1470 DESC 'A reference to a reusable policy time period 1471 condition.' 1472 EQUALITY distinguishedNameMatch 1473 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1474 SINGLE-VALUE 1475 ) 1477 A DIT content rule could be written to enable an instance of 1478 pcimRuleValidityAssociation to have attached to it an instance of the 1479 auxiliary class pcimTPCAuxClass, or one of its subclasses. This would be 1480 used to formalize the semantics of the PolicyRuleValidityPeriod 1481 aggregation [1]. 1483 Similarly, three separate DIT structure rules could be written. Each of 1484 these DIT structure rules would refer to a specific name form that 1485 defined two important semantics. First, each name form would identify 1486 one of the three possible naming attributes (i.e., 1487 pcimValidityConditionName, cn, and orderedCIMKeys) for the 1488 pcimRuleValidityAssociation object class. Second, each name form would 1489 require that an instance of the pcimRuleValidityAssociation class have 1490 as its superior an instance of the pcimRule class. This structure rule 1491 SHOULD also include a superiorStructureRule (see Note 2 at the beginning 1492 of section 5). 1494 5.6. The Class pcimRuleActionAssociation 1496 This class contains an attribute to represent the one property of the 1497 PCIM PolicyActionInPolicyRule association, ActionOrder. This property is 1498 used to specify an order for executing the actions associated with a 1499 policy rule. Instances of this class are related to an instance of 1500 pcimRule via DIT containment. The actions themselves are represented by 1501 auxiliary subclasses of the auxiliary class pcimActionAuxClass. 1503 These auxiliary classes are attached directly to instances of 1504 pcimRuleActionAssociation for rule-specific policy actions. For a 1505 reusable policy action, the pcimAction auxiliary subclass is attached to 1506 an instance of the class pcimPolicyInstance (which is presumably 1507 associated with a pcimRepository by DIT containment), and the 1508 pcimActionDN attribute (of this class) is used to reference the reusable 1509 pcimCondition instance. 1511 The class definition is as follows: 1513 ( NAME 'pcimRuleActionAssociation' 1514 DESC 'This class contains attributes characterizing the 1515 relationship between a policy rule and one of its 1516 policy actions.' 1517 SUP pcimPolicy 1518 MUST ( pcimActionOrder ) 1519 MAY ( pcimActionName $ pcimActionDN ) 1520 ) 1522 The pcimActionName attribute is used to define a user-friendly name of 1523 this action, and may be used as a naming attribute if desired. This 1524 attribute is defined as follows: 1526 ( 1527 NAME 'pcimActionName' 1528 DESC 'A user-friendly name for a policy action.' 1529 EQUALITY caseIgnoreMatch 1530 ORDERING caseIgnoreOrderingMatch 1531 SUBSTR caseIgnoreSubstringsMatch 1532 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1533 SINGLE-VALUE 1534 ) 1536 The pcimActionOrder attribute is an unsigned integer that is used to 1537 indicate the relative position of an action in a sequence of actions 1538 that are associated with a given policy rule. When this number is 1539 positive, it indicates a place in the sequence of actions to be 1540 performed, with smaller values indicating earlier positions in the 1541 sequence. If the value is zero, then this indicates that the order is 1542 irrelevant. Note that if two or more actions have the same non-zero 1543 value, they may be performed in any order as long as they are each 1544 performed in the correct place in the overall sequence of actions. This 1545 attribute is defined as follows: 1547 ( 1548 NAME 'pcimActionOrder' 1549 DESC 'An integer indicating the relative order of an action 1550 in the context of a policy rule.' 1551 EQUALITY integerMatch 1552 ORDERING integerOrderingMatch 1553 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1554 SINGLE-VALUE 1555 ) 1557 Note: if the value of the pcimActionOrder field is negative, then it 1558 SHOULD be treated as an error and any policy rule that refers to this 1559 entry SHOULD be disabled. 1561 The pcimActionDN attribute is a DN that references a reusable policy 1562 action. It is defined as follows: 1564 ( 1565 NAME 'pcimActionDN' 1566 DESC 'A DN that references a reusable policy action.' 1567 EQUALITY distinguishedNameMatch 1568 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 1569 SINGLE-VALUE 1570 ) 1572 A DIT content rule could be written to enable an instance of 1573 pcimRuleActionAssociation to have attached to it an instance of the 1574 auxiliary class pcimActionAuxClass, or one of its subclasses. This would 1575 be used to formalize the semantics of the PolicyActionInPolicyRule 1576 association. Specifically, this would be used to represent a rule- 1577 specific policy action [1]. 1579 Similarly, three separate DIT structure rules could be written. Each of 1580 these DIT structure rules would refer to a specific name form that 1581 defined two important semantics. First, each name form would identify 1582 one of the three possible naming attributes (i.e., pcimActionName, cn, 1583 and orderedCIMKeys) for the pcimRuleActionAssociation object class. 1584 Second, each name form would require that an instance of the 1585 pcimRuleActionAssociation class have as its superior an instance of the 1586 pcimRule class. This structure rule should also include a 1587 superiorStructureRule (see Note 2 at the beginning of section 5). 1589 5.7. The Auxiliary Class pcimConditionAuxClass 1591 The purpose of a policy condition is to determine whether or not the set 1592 of actions (contained in the pcimRule that the condition applies to) 1593 should be executed or not. This class defines the basic organizational 1594 semantics of a policy condition, as specified in [1]. Subclasses of this 1595 auxiliary class can be attached to instances of three other classes in 1596 the PCLS. When a subclass of this class is attached to an instance of 1597 pcimRuleConditionAssociation, or to an instance of pcimRule, it 1598 represents a rule-specific policy condition. When a subclass of this 1599 class is attached to an instance of pcimPolicyInstance, it represents a 1600 reusable policy condition. 1602 Since all of the classes to which subclasses of this auxiliary class may 1603 be attached are derived from the pcimPolicy class, the attributes of 1604 pcimPolicy will already be defined for the entries to which these 1605 subclasses attach. Thus, this class is derived directly from "top". 1607 The class definition is as follows: 1609 ( NAME 'pcimConditionAuxClass' 1610 DESC 'A class representing a condition to be evaluated in 1611 conjunction with a policy rule.' 1612 SUP top 1613 AUXILIARY 1614 ) 1616 5.8. The Auxiliary Class pcimTPCAuxClass 1618 The PCIM defines a time period class, PolicyTimePeriodCondition, to 1619 provide a means of representing the time periods during which a policy 1620 rule is valid, i.e., active. It also defines an aggregation, 1621 PolicyRuleValidityPeriod, so that time periods can be associated with a 1622 PolicyRule. The LDAP mapping also provides two classes, one for the 1623 time condition itself, and one for the aggregation. 1625 In the PCIM, the time period class is named PolicyTimePeriodCondition. 1626 However, the resulting name of the auxiliary class in this mapping 1627 (pcimTimePeriodConditionAuxClass) exceeds the length of a name that some 1628 directories can store. Therefore, the name has been shortened to 1629 pcimTPCAuxClass. 1631 The class definition is as follows: 1633 ( NAME 'pcimTPCAuxClass' 1634 DESC 'This provides the capability of enabling or disabling 1635 a policy rule according to a predetermined schedule.' 1636 SUP pcimConditionAuxClass 1637 AUXILIARY 1638 MAY ( pcimTPCTime $ pcimTPCMonthOfYearMask $ 1639 pcimTPCDayOfMonthMask $ pcimTPCDayOfWeekMask $ 1640 pcimTPCTimeOfDayMask $ pcimTPCLocalOrUtcTime ) 1641 ) 1643 The attributes of the pcimTPCAuxClass are defined as follows. 1645 The pcimTPCTime attribute represents the time period that a policy rule 1646 is enabled for. This attribute is defined as a string in [1] with a 1647 special format which defines a time period with a starting date and an 1648 ending date separated by a forward slash ("/"), as follows: 1650 yyyymmddThhmmss/yyyymmddThhmmss 1652 where the first date and time may be replaced with the string 1653 "THISANDPRIOR" or the second date and time may be replaced with the 1654 string "THISANDFUTURE". This attribute is defined as follows: 1656 ( 1657 NAME 'pcimTPCTime' 1658 DESC 'The start and end times on which a policy rule is 1659 valid.' 1660 EQUALITY caseIgnoreMatch 1661 ORDERING caseIgnoreOrderingMatch 1662 SUBSTR caseIgnoreSubstringsMatch 1663 SYNTAX 1.3.6.1.4.1.1466.115.121.1.44 1664 SINGLE-VALUE 1665 ) 1667 The next four attributes (pcimTPCMonthOfYearMask, pcimTPCDayOfMonthMask, 1668 pcimTPCDayOfWeekMask, and pcimTPCTimeOfDayMask) are all defined as octet 1669 strings in [1]. However, the semantics of each of these attributes are 1670 contained in bit strings of various fixed lengths. Therefore, the PCLS 1671 uses a syntax of Bit String to represent each of them. The definition of 1672 these four attributes are as follows. 1674 The pcimTPCMonthOfYearMask attribute defines a 12-bit mask identifying 1675 the months of the year in which a policy rule is valid. The format is a 1676 bit string of length 12, representing the months of the year from 1677 January through December. The definition of this attribute is as 1678 follows: 1680 ( 1681 NAME 'pcimTPCMonthOfYearMask' 1682 DESC 'This identifies the valid months of the year for a 1683 policy rule using a 12-bit string that represents the 1684 months of the year from January through December.' 1685 EQUALITY bitStringMatch 1686 SYNTAX 1.3.6.1.4.1.1466.115.121.1.6 1687 SINGLE-VALUE 1688 ) 1690 The pcimTPCMonthOfDayMask attribute defines a mask identifying the days 1691 of the month on which a policy rule is valid. The format is a bit string 1692 of length 62. The first 31 positions represent the days of the month in 1693 ascending order, from day 1 to day 31. The next 31 positions represent 1694 the days of the month in descending order, from the last day to the day 1695 31 days from the end. The definition of this attribute is as follows: 1697 ( 1698 NAME 'pcimTPCDayOfMonthMask' 1699 DESC 'This identifies the valid days of the month for a 1700 policy rule using a 62-bit string. The first 31 1701 positions represent the days of the month in ascending 1702 order, and the next 31 positions represent the days of 1703 the month in descending order.' 1704 EQUALITY bitStringMatch 1705 SYNTAX 1.3.6.1.4.1.1466.115.121.1.6 1706 SINGLE-VALUE 1707 ) 1709 The pcimTPCDayOfWeekMask attribute defines a mask identifying the days 1710 of the week on which a policy rule is valid. The format is a bit string 1711 of length 7, representing the days of the week from Sunday through 1712 Saturday. The definition of this attribute is as follows: 1714 ( 1715 NAME 'pcimTPCDayOfWeekMask' 1716 DESC 'This identifies the valid days of the week for a 1717 policy rule using a 7-bit string. This represents 1718 the days of the week from Sunday through Saturday.' 1719 EQUALITY bitStringMatch 1720 SYNTAX 1.3.6.1.4.1.1466.115.121.1.6 1721 SINGLE-VALUE 1722 ) 1724 The pcimTPCTimeOfDayMask attribute defines the range of times at which a 1725 policy rule is valid. If the second time is earlier than the first, then 1726 the interval spans midnight. The format of the string is 1727 Thhmmss/Thhmmss. The definition of this attribute is as follows: 1729 ( 1730 NAME 'pcimTPCTimeOfDayMask' 1731 DESC 'This identifies the valid range of times for a policy 1732 using the format Thhmmss/Thhmmss.' 1733 EQUALITY caseIgnoreMatch 1734 ORDERING caseIgnoreOrderingMatch 1735 SUBSTR caseIgnoreSubstringsMatch 1736 SYNTAX 1.3.6.1.4.1.1466.115.121.1.44 1737 SINGLE-VALUE 1738 ) 1740 Finally, the pcimTPCLocalOrUtcTime attribute is used to choose between 1741 local or UTC time representation. This is mapped as a simple integer 1742 syntax, with the value of 1 representing local time and the value of 2 1743 representing UTC time. The definition of this attribute is as follows: 1745 ( 1746 NAME 'pcimTPCLocalOrUtcTime' 1747 DESC 'This defines whether the times in this instance 1748 represent local (value=1) times or UTC (value=2) 1749 times.' 1750 EQUALITY integerMatch 1751 ORDERING integerOrderingMatch 1752 SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 1753 SINGLE-VALUE 1754 ) 1756 Note: if the value of the pcimTPCLocalOrUtcTime is not 1 or 2, then this 1757 SHOULD be considered an error and the policy rule SHOULD be disabled. 1759 5.9. The Auxiliary Class pcimConditionVendorAuxClass 1761 This class provides a general extension mechanism for representing 1762 policy conditions that have not been modeled with specific properties. 1763 Instead, its two properties are used to define the content and format of 1764 the condition, as explained below. This class is intended for vendor- 1765 specific extensions that are not amenable to using pcimCondition; 1766 standardized extensions SHOULD NOT use this class. 1768 The class definition is as follows: 1770 ( NAME 'pcimConditionVendorAuxClass' 1771 DESC 'A class that defines a registered means to describe a 1772 policy condition.' 1773 SUP pcimConditionAuxClass 1774 AUXILIARY 1775 MAY ( pcimVendorConstraintData $ 1776 pcimVendorConstraintEncoding ) 1777 ) 1779 The pcimVendorConstraintData attribute is a multi-valued attribute. It 1780 provides a general mechanism for representing policy conditions that 1781 have not been modeled as specific attributes. This information is 1782 encoded in a set of octet strings. The format of the octet strings is 1783 identified by the OID stored in the pcimVendorConstraintEncoding 1784 attribute. This attribute is defined as follows: 1786 ( 1787 NAME 'pcimVendorConstraintData' 1788 DESC 'Mechanism for representing constraints that have not 1789 been modeled as specific attributes. Their format is 1790 identified by the OID stored in the attribute 1791 pcimVendorConstraintEncoding.' 1792 EQUALITY octetStringMatch 1793 ORDERING octetStringOrderingMatch 1794 SUBSTR octetStringSubstringsMatch 1795 SYNTAX 1.3.6.1.4.1.1466.115.121.1.40 1796 ) 1798 The pcimVendorConstraintEncoding attribute is used to identify the 1799 format and semantics for the pcimVendorConstraintData attribute. This 1800 attribute is defined as follows: 1802 ( 1803 NAME 'pcimVendorConstraintEncoding' 1804 DESC 'An OID identifying the format and semantics for the 1805 pcimVendorConstraintData for this instance.' 1806 EQUALITY objectIdentifierMatch 1807 SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 1808 SINGLE-VALUE 1809 ) 1811 5.10. The Auxiliary Class pcimActionAuxClass 1813 The purpose of a policy action is to execute one or more operations that 1814 will affect network traffic and/or systems, devices, etc. in order to 1815 achieve a desired policy state. This class is used to represent an 1816 action to be performed as a result of a policy rule whose condition 1817 clause was satisfied. 1819 Subclasses of this auxiliary class can be attached to instances of three 1820 other classes in the PCLS. When a subclass of this class is attached to 1821 an instance of pcimRuleActionAssociation, or to an instance of pcimRule, 1822 it represents a rule-specific policy action. When a subclass of this 1823 class is attached to an instance of pcimPolicyInstance, it represents a 1824 reusable policy action. 1826 Since all of the classes to which subclasses of this auxiliary class may 1827 be attached are derived from the pcimPolicy class, the attributes of the 1828 pcimPolicy class will already be defined for the entries to which these 1829 subclasses attach. Thus, this class is derived directly from "top". 1831 The class definition is as follows: 1833 ( NAME 'pcimActionAuxClass' 1834 DESC 'A class representing an action to be performed as a 1835 result of a policy rule.' 1836 SUP top 1837 AUXILIARY 1838 ) 1840 5.11. The Auxiliary Class pcimActionVendorAuxClass 1842 The purpose of this class is to provide a general extension mechanism 1843 for representing policy actions that have not been modeled with specific 1844 properties. Instead, its two properties are used to define the content 1845 and format of the action, as explained below. 1847 As its name suggests, this class is intended for vendor-specific 1848 extensions that are not amenable to using the standard pcimAction class. 1849 Standardized extensions SHOULD NOT use this class. 1851 The class definition is as follows: 1853 ( NAME 'pcimActionVendorAuxClass' 1854 DESC 'A class that defines a registered means to describe a 1855 policy action.' 1856 SUP pcimActionAuxClass 1857 AUXILIARY 1858 MAY ( pcimVendorActionData $ pcimVendorActionEncoding ) 1859 ) 1861 The pcimVendorActionData attribute is a multi-valued attribute. It 1862 provides a general mechanism for representing policy actions that have 1863 not been modeled as specific attributes. This information is encoded in 1864 a set of octet strings. The format of the octet strings is identified by 1865 the OID stored in the pcimVendorActionEncoding attribute. This attribute 1866 is defined as follows: 1868 ( 1869 NAME 'pcimVendorActionData' 1870 DESC ' Mechanism for representing policy actions that have 1871 not been modeled as specific attributes. Their format 1872 is identified by the OID stored in the attribute 1873 pcimVendorActionEncoding.' 1874 EQUALITY octetStringMatch 1875 ORDERING octetStringOrderingMatch 1876 SUBSTR octetStringSubstringsMatch 1877 SYNTAX 1.3.6.1.4.1.1466.115.121.1.40 1878 ) 1880 The pcimVendorActionEncoding attribute is used to identify the format 1881 and semantics for the pcimVendorActionData attribute. This attribute is 1882 defined as follows: 1884 ( 1885 NAME 'pcimVendorActionEncoding' 1886 DESC 'An OID identifying the format and semantics for the 1887 pcimVendorActionData attribute of this instance.' 1888 EQUALITY objectIdentifierMatch 1889 SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 1890 SINGLE-VALUE 1891 ) 1893 5.12. The Class pcimPolicyInstance 1895 This class is not defined in the PCIM. Its role is to serve as a 1896 structural class to which auxiliary classes representing policy 1897 information are attached when the information is reusable. For 1898 auxiliary classes representing policy conditions and policy actions, 1899 there are alternative structural classes that may be used. See Section 1900 4.4 for a complete discussion of reusable policy conditions and actions, 1901 and of the role that this class plays in how they are represented. 1903 The class definition is as follows: 1905 ( NAME 'pcimPolicyInstance' 1906 DESC 'A structural class to which aux classes containing 1907 reusable policy information can be attached.' 1908 SUP pcimPolicy 1909 MAY ( pcimPolicyInstanceName ) 1910 ) 1912 The pcimPolicyInstanceName attribute is used to define a user-friendly 1913 name of this class, and may be used as a naming attribute if desired. It 1914 is defined as follows: 1916 ( NAME 'pcimPolicyInstanceName' 1917 DESC 'The user-friendly name of this policy instance.' 1918 EQUALITY caseIgnoreMatch 1919 ORDERING caseIgnoreOrderingMatch 1920 SUBSTR caseIgnoreSubstringsMatch 1921 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 1922 SINGLE-VALUE 1923 ) 1925 A DIT content rule could be written to enable an instance of 1926 pcimPolicyInstance to have attached to it either instances of one or 1927 more of the auxiliary object classes pcimConditionAuxClass and 1928 pcimActionAuxClass. Since these semantics do not include specifying any 1929 properties, the content rule would not need to specify any attributes. 1930 Note that other content rules could be defined to enable other policy- 1931 related auxiliary classes to be attached to pcimPolicyInstance. 1933 Similarly, three separate DIT structure rules could be written. Each of 1934 these DIT structure rules would refer to a specific name form that 1935 defined two important semantics. First, each name form would identify 1936 one of the three possible naming attributes (i.e., 1937 pcimPolicyInstanceName, cn, and orderedCIMKeys) for this object class. 1938 Second, each name form would require that an instance of the 1939 pcimPolicyInstance class have as its superior an instance of the 1940 pcimRepository class. This structure rule SHOULD also include a 1941 superiorStructureRule (see Note 2 at the beginning of section 5). 1943 5.13. The Auxiliary Class pcimElementAuxClass 1945 This class introduces no additional attributes, beyond those defined in 1946 the class pcimPolicy from which it is derived. Its role is to "tag" an 1947 instance of a class defined outside the realm of policy information as 1948 represented by PCIM as being nevertheless relevant to a policy 1949 specification. This tagging can potentially take place at two levels: 1951 - Every instance to which pcimElementAuxClass is attached becomes 1952 an instance of the class pcimPolicy, since pcimElementAuxClass is a 1953 subclass of pcimPolicy. Searching for object class="pcimPolicy" 1954 will return the instance. (As noted earlier, this approach does 1955 NOT work for some directory implementations. To accommodate these 1956 implementations, policy-related entries SHOULD be tagged with the 1957 pcimKeyword "POLICY".) 1959 - With the pcimKeywords attribute that it inherits from pcimPolicy, 1960 an instance to which pcimElementAuxClass is attached can be 1961 tagged as being relevant to a particular type or category of 1962 policy information, using standard keywords, administrator-defined 1963 keywords, or both. 1965 The class definition is as follows: 1967 ( NAME 'pcimElementAuxClass' 1968 DESC 'An auxiliary class used to tag instances of classes 1969 defined outside the realm of policy as relevant to a 1970 particular policy specification.' 1971 SUP pcimPolicy 1972 AUXILIARY 1973 ) 1975 5.14. The Three Policy Repository Classes 1977 These classes provide a container for reusable policy information, such 1978 as reusable policy conditions and/or reusable policy actions. This 1979 document is concerned with mapping just the properties that appear in 1980 these classes. Conceptually, this may be thought of as a special 1981 location in the DIT where policy information may reside. 1983 To maximize flexibility, the pcimRepository class is defined as 1984 abstract. A subclass pcimRepositoryAuxClass provides for auxiliary 1985 attachment to another entry, while a structural subclass 1986 pcimRepositoryInstance is available to represent a policy repository as 1987 a standalone entry. 1989 The definition for the pcimRepository class is as follows: 1991 ( NAME 'pcimRepository' 1992 DESC 'A container for reusable policy information.' 1993 SUP dlm1AdminDomain 1994 ABSTRACT 1995 MAY ( pcimRepositoryName ) 1996 ) 1998 The pcimRepositoryName attribute is used to define a user-friendly name 1999 of this class, and may be used as a naming attribute if desired. It is 2000 defined as follows: 2002 ( NAME 'pcimRepositoryName' 2003 DESC 'The user-friendly name of this policy repository.' 2004 EQUALITY caseIgnoreMatch 2005 ORDERING caseIgnoreOrderingMatch 2006 SUBSTR caseIgnoreSubstringsMatch 2007 SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 2008 SINGLE-VALUE 2009 ) 2011 The two subclasses of pcimRepository are defined as follows. First, the 2012 pcimRepositoryAuxClass is an auxiliary class that can be used to 2013 aggregate reusable policy information. It is defined as follows: 2015 ( NAME 'pcimRepositoryAuxClass' 2016 DESC 'An auxiliary class that can be used to aggregate 2017 reusable policy information.' 2018 SUP pcimRepository 2019 AUXILIARY 2020 ) 2022 In cases where structural classes are needed instead of an auxiliary 2023 class, the pcimRepositoryInstance class is a structural class that can 2024 be used to aggregate reusable policy information. It is defined as 2025 follows: 2027 ( NAME 'pcimRepositoryInstance' 2028 DESC 'A structural class that can be used to aggregate 2029 reusable policy information.' 2030 SUP pcimRepository 2031 STRUCTURAL 2032 ) 2034 Three separate DIT structure rules could be written for this class. Each 2035 of these DIT structure rules would refer to a specific name form that 2036 enabled an instance of the pcimRepository class to be named under any 2037 superior using one of the three possible naming attributes (i.e., 2038 pcimRepositoryName, cn, and orderedCIMKeys). This structure rule SHOULD 2039 also include a superiorStructureRule (see Note 2 at the beginning of 2040 section 5). 2042 5.15. The Auxiliary Class pcimSubtreesPtrAuxClass 2044 This auxiliary class provides a single, multi-valued attribute that 2045 references a set of objects that are at the root of DIT subtrees 2046 containing policy-related information. By attaching this attribute to 2047 instances of various other classes, a policy administrator has a 2048 flexible way of providing an entry point into the directory that allows 2049 a client to locate and retrieve the policy information relevant to it. 2051 It is intended that these entries are placed in the DIT such that well- 2052 known DNs can be used to reference a well-known structural entry that 2053 has the pcimSubtreesPtrAuxClass attached to it. In effect, this defines 2054 a set of entry points. Each of these entry points can contain and/or 2055 reference all related policy entries for any well-known policy domains. 2056 The pcimSubtreesPtrAuxClass functions as a tag to identify portions of 2057 the DIT that contain policy information. 2059 This object does not provide the semantic linkages between individual 2060 policy objects, such as those between a policy group and the policy 2061 rules that belong to it. Its only role is to enable efficient bulk 2062 retrieval of policy-related objects, as described in Section 4.5. 2064 Once the objects have been retrieved, a directory client can determine 2065 the semantic linkages by following references contained in multi-valued 2066 attributes, such as pcimRulesAuxContainedSet. 2068 Since policy-related objects will often be included in the DIT subtree 2069 beneath an object to which this auxiliary class is attached, a client 2070 SHOULD request the policy-related objects from the subtree under the 2071 object with these references at the same time that it requests the 2072 references themselves. 2074 Since clients are expected to behave in this way, the policy 2075 administrator SHOULD make sure that this subtree does not contain so 2076 many objects unrelated to policy that an initial search done in this way 2077 results in a performance problem. The pcimSubtreesPtrAuxClass SHOULD 2078 NOT be attached to the partition root for a large directory partition 2079 containing a relatively few number of policy-related objects along with 2080 a large number of objects unrelated to policy (again, "policy" here 2081 refers to the PCIM, not the X.501, definition and use of "policy"). A 2082 better approach would be to introduce a container object immediately 2083 below the partition root, attach pcimSubtreesPtrAuxClass to this 2084 container object, and then place all of the policy-related objects in 2085 that subtree. 2087 The class definition is as follows: 2089 ( NAME 'pcimSubtreesPtrAuxClass' 2090 DESC 'An auxiliary class providing DN references to roots of 2091 DIT subtrees containing policy-related objects.' 2092 SUP top 2093 AUXILIARY 2094 MAY ( pcimSubtreesAuxContainedSet ) 2095 ) 2097 The attribute pcimSubtreesAuxContainedSet provides an unordered set of 2098 DN references to instances of one or more objects under which policy- 2099 related information is present. The objects referenced may or may not 2100 themselves contain policy-related information. The attribute definition 2101 is as follows: 2103 ( 2104 NAME 'pcimSubtreesAuxContainedSet' 2105 DESC 'DNs of objects that serve as roots for DIT subtrees 2106 containing policy-related objects.' 2107 EQUALITY distinguishedNameMatch 2108 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 2109 ) 2111 Note that the cn attribute does NOT need to be defined for this class. 2112 This is because an auxiliary class is used as a means to collect common 2113 attributes and treat them as properties of an object. A good analogy is 2114 a #include file, except that since an auxiliary class is a class, all 2115 the benefits of a class (e.g., inheritance) can be applied to an 2116 auxiliary class. 2118 5.16. The Auxiliary Class pcimGroupContainmentAuxClass 2120 This auxiliary class provides a single, multi-valued attribute that 2121 references a set of pcimGroups. By attaching this attribute to 2122 instances of various other classes, a policy administrator has a 2123 flexible way of providing an entry point into the directory that allows 2124 a client to locate and retrieve the pcimGroups relevant to it. 2126 As is the case with pcimRules, a policy administrator might have several 2127 different references to a pcimGroup in the overall directory structure. 2128 The pcimGroupContainmentAuxClass is the mechanism that makes it possible 2129 for the policy administrator to define all these different references. 2131 The class definition is as follows: 2133 ( NAME 'pcimGroupContainmentAuxClass' 2134 DESC 'An auxiliary class used to bind pcimGroups to an 2135 appropriate container object.' 2136 SUP top 2137 AUXILIARY 2138 MAY ( pcimGroupsAuxContainedSet ) 2139 ) 2141 The attribute pcimGroupsAuxContainedSet provides an unordered set of 2142 references to instances of one or more pcimGroups associated with the 2143 instance of a structural class to which this attribute has been 2144 appended. 2146 The attribute definition is as follows: 2148 ( 2149 NAME 'pcimGroupsAuxContainedSet' 2150 DESC 'DNs of pcimGroups associated in some way with the 2151 instance to which this attribute has been appended.' 2152 EQUALITY distinguishedNameMatch 2153 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 2154 ) 2156 Note that the cn attribute does NOT have to be defined for this class 2157 for the same reasons as those given for the pcimSubtreesPtrAuxClass in 2158 section 5.15. 2160 5.17. The Auxiliary Class pcimRuleContainmentAuxClass 2162 This auxiliary class provides a single, multi-valued attribute that 2163 references a set of pcimRules. By attaching this attribute to instances 2164 of various other classes, a policy administrator has a flexible way of 2165 providing an entry point into the directory that allows a client to 2166 locate and retrieve the pcimRules relevant to it. 2168 A policy administrator might have several different references to a 2169 pcimRule in the overall directory structure. For example, there might 2170 be references to all pcimRules for traffic originating in a particular 2171 subnet from a directory entry that represents that subnet. At the same 2172 time, there might be references to all pcimRules related to a particular 2173 DiffServ setting from an instance of a pcimGroup explicitly introduced 2174 as a container for DiffServ-related pcimRules. The 2175 pcimRuleContainmentAuxClass is the mechanism that makes it possible for 2176 the policy administrator to define all these separate references. 2178 The class definition is as follows: 2180 ( NAME 'pcimRuleContainmentAuxClass' 2181 DESC 'An auxiliary class used to bind pcimRules to an 2182 appropriate container object.' 2183 SUP top 2184 AUXILIARY 2185 MAY ( pcimRulesAuxContainedSet ) 2186 ) 2188 The attribute pcimRulesAuxContainedSet provides an unordered set of 2189 references to one or more instances of pcimRules associated with the 2190 instance of a structural class to which this attribute has been 2191 appended. The attribute definition is as follows: 2193 ( 2194 NAME 'pcimRulesAuxContainedSet' 2195 DESC 'DNs of pcimRules associated in some way with the 2196 instance to which this attribute has been appended.' 2197 EQUALITY distinguishedNameMatch 2198 SYNTAX 1.3.6.1.4.1.1466.115.121.1.12 2199 ) 2201 The cn attribute does NOT have to be defined for this class for the same 2202 reasons as those given for the pcimSubtreesPtrAuxClass in section 5.15. 2204 6. Extending the Classes Defined in This Document 2206 The following subsections provide general guidance on how to create a 2207 domain-specific schema derived from this document, discuss how the 2208 vendor classes in the PCLS should be used, and explain how 2209 policyTimePeriodConditions are related to other policy conditions. 2211 6.1. Subclassing pcimConditionAuxClass and pcimActionAuxClass 2213 In Section 4.4, there is a discussion of how, by representing policy 2214 conditions and policy actions as auxiliary classes in a schema, the 2215 flexibility is retained to instantiate a particular condition or action 2216 as either rule-specific or reusable. This flexibility is lost if a 2217 condition or action class is defined as structural rather than 2218 auxiliary. For standardized schemata, this document specifies that 2219 domain-specific information MUST be expressed in auxiliary subclasses of 2220 pcimConditionAuxClass and pcimActionAuxClass. It is RECOMMENDED that 2221 non-standardized schemata follow this practice as well. 2223 6.2. Using the Vendor Policy Attributes 2225 As discussed Section 5.9, the attributes pcimVendorConstraintData and 2226 pcimVendorConstraintEncoding are included in the 2227 pcimConditionVendorAuxClass to provide a mechanism for representing 2228 vendor-specific policy conditions that are not amenable to being 2229 represented with the pcimCondition class (or its subclasses). The 2230 attributes pcimVendorActionData and pcimVendorActionEncoding in the 2231 pcimActionVendorAuxClass class play the same role with respect to 2232 actions. This enables interoperability between different vendors who 2233 could not otherwise interoperate. 2235 For example, imagine a network composed of access devices from vendor A, 2236 edge and core devices from vendor B, and a policy server from vendor C. 2237 It is desirable for this policy server to be able to configure and 2238 manage all of the devices from vendors A and B. Unfortunately, these 2239 devices will in general have little in common (e.g., different 2240 mechanisms, different ways for controlling those mechanisms, different 2241 operating systems, different commands, and so forth). The extension 2242 conditions provide a way for vendor-specific commands to be encoded as 2243 octet strings, so that a single policy server can commonly manage 2244 devices from different vendors. 2246 6.3. Using Time Validity Periods 2248 Time validity periods are defined as an auxiliary subclass of 2249 pcimConditionAuxClass, called pcimTPCAuxClass. This is to allow their 2250 inclusion in the AND/OR condition definitions for a pcimRule. Care 2251 should be taken not to subclass pcimTPCAuxClass to add domain-specific 2252 condition properties. 2254 For example, it would be incorrect to add IPsec- or QoS-specific 2255 condition properties to the pcimTPCAuxClass class, just because IPsec or 2256 QoS includes time in its condition definition. The correct subclassing 2257 would be to create IPsec or QoS-specific subclasses of 2258 pcimConditionAuxClass and then combine instances of these domain- 2259 specific condition classes with the appropriate validity period 2260 criteria. This is accomplished using the AND/OR association capabilities 2261 for policy conditions in pcimRules. 2263 7. Security Considerations 2265 The PCLS, presented in this document, provides a mapping of the object- 2266 oriented model for describing policy information (PCIM) into a data 2267 model that forms the basic framework for describing the structure of 2268 policy data, in the case where the policy repository takes the form of 2269 an LDAP-accessible directory. 2271 PCLS is not intended to represent any particular system design or 2272 implementation. PCLS is not directly useable in a real world system, 2273 without the discipline-specific mappings that are works in progress in 2274 the Policy Framework Working Group of the IETF. 2276 These other derivative documents, which use PCIM and its discipline- 2277 specific extensions as a base, will need to convey more specific 2278 security considerations (refer to RFC3060 for more information.) 2280 The reason that PCLS, as defined here, is not representative of any 2281 real-world system, is that its object classes were designed to be 2282 independent of any specific discipline, or policy domain. For example, 2283 DiffServ and IPsec represent two different policy domains. Each document 2284 that extends PCIM to one of these domains will derive subclasses from 2285 the classes and relationships defined in PCIM, in order to represent 2286 extensions of a generic model to cover specific technical domains. 2288 PCIM-derived documents will thus subclass the PCIM classes into classes 2289 specific to each technical policy domain (QOS, IPsec, etc.), which will, 2290 in turn, be mapped, to directory-specific schemata consistent with the 2291 PCLS documented here. 2293 Even though discipline-specific security requirements are not 2294 appropriate for PCLS, specific security requirements MUST be defined for 2295 each operational real-world application of PCIM. Just as there will be 2296 a wide range of operational, real-world systems using PCIM, there will 2297 also be a wide range of security requirements for these systems. Some 2298 operational, real-world systems that are deployed using PCLS may have 2299 extensive security requirements that impact nearly all object classes 2300 utilized by such a system, while other systems' security requirements 2301 might have very little impact. 2303 The derivative documents, discussed above, will create the context for 2304 applying operational, real-world, system-level security requirements 2305 against the various models that derive from PCIM, consistent with PCLS. 2307 In some real-world scenarios, the values associated with certain 2308 properties, within certain instantiated object classes, may represent 2309 information associated with scarce, and/or costly (and therefore 2310 valuable) resources. It may be the case that these values must not be 2311 disclosed to, or manipulated by, unauthorized parties. 2313 Since this document forms the basis for the representation of a policy 2314 data model in a specific format (an LDAP-accessible directory), it is 2315 herein appropriate to reference the data model-specific tools and 2316 mechanisms that are available for achieving the authentication and 2317 authorization implicit in a requirement that restricts read and/or read- 2318 write access to these values stored in a directory. 2320 LDAP-specific authentication and authorization tools and mechanisms are 2321 found in the following standards track documents, which are appropriate 2322 for application to the management of security applied to policy data 2323 models stored in an LDAP-accessible directory: 2325 - RFC 2829 (Authentication Methods for LDAP) 2326 - RFC 2830 (Lightweight Directory Access Protocol (v3): Extension 2327 for Transport Layer Security) 2329 Any identified security requirements that are not dealt with in the 2330 appropriate discipline-specific information model documents, or in this 2331 document, MUST be dealt with in the derivative data model documents 2332 which are specific to each discipline. 2334 8. Intellectual Property 2336 The IETF takes no position regarding the validity or scope of any 2337 intellectual property or other rights that might be claimed to pertain 2338 to the implementation or use of the technology described in this 2339 document or the extent to which any license under such rights might or 2340 might not be available; neither does it represent that it has made any 2341 effort to identify any such rights. Information on the IETF's 2342 procedures with respect to rights in standards-track and standards- 2343 related documentation can be found in BCP-11. 2345 Copies of claims of rights made available for publication and any 2346 assurances of licenses to be made available, or the result of an attempt 2347 made to obtain a general license or permission for the use of such 2348 proprietary rights by implementers or users of this specification can be 2349 obtained from the IETF Secretariat. 2351 The IETF invites any interested party to bring to its attention any 2352 copyrights, patents or patent applications, or other proprietary rights 2353 that may cover technology that may be required to practice this 2354 standard. Please address the information to the IETF Executive 2355 Director. 2357 9. Acknowledgments 2359 We would like to thank Kurt Zeilenga, Roland Hedburg, and Steven Legg 2360 for doing a review of this document and making many helpful suggestions 2361 and corrections. 2363 Several of the policy classes in this model first appeared in early IETF 2364 drafts on IPsec policy and QoS policy. The authors of these drafts were 2365 Partha Bhattacharya, Rob Adams, William Dixon, Roy Pereira, Raju Rajan, 2366 Jean-Christophe Martin, Sanjay Kamat, Michael See, Rajiv Chaudhury, 2367 Dinesh Verma, George Powers, and Raj Yavatkar. 2369 This document is closely aligned with the work being done in the 2370 Distributed Management Task Force (DMTF) Policy and Networks working 2371 groups. We would especially like to thank Lee Rafalow, Glenn Waters, 2372 David Black, Michael Richardson, Mark Stevens, David Jones, Hugh Mahon, 2373 Yoram Snir, and Yoram Ramberg for their helpful comments. 2375 10. References 2377 [1] Moore, B., and E. Ellesson, J. Strassner, A. Westerinen "Policy 2378 Core Information Model -- Version 1 Specification", RFC 3060, 2379 February 2001. 2381 [2] Wahl, M., and A. Coulbeck, T. Howes, S. Kille, "Lightweight 2382 Directory Access Protocol (v3): Attribute Syntax Definitions", RFC 2383 2252, December 1997. 2385 [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement 2386 Levels", BCP 14, RFC 2119, March 1997. 2388 [4] Hovey, R., and S. Bradner, "The Organizations Involved in the IETF 2389 Standards Process", BCP 11, RFC 2028, October 1996. 2390 [5] The Directory: Models. ITU-T Recommendation X.501, 2001. 2392 [6] Strassner, J., policy architecture BOF presentation, 42nd IETF 2393 Meeting, Chicago, Illinois, October 1998. Minutes of this BOF are 2394 available at the following location: 2395 http://www.ietf.org/proceedings/98aug/index.html. 2397 [7] DMTF web site, http://www.dmtf.org. 2399 [8] Yavatkar, R., and R. Guerin, D. Pendarakis, "A Framework for 2400 Policy-based Admission Control", RFC 2753, January 2000. 2402 [9] Distributed Management Task Force, Inc., "Common Information 2403 Model (CIM) Specification", Version 2.2, June 14, 1999. This 2404 document is available on the following DMTF web page: 2405 http://www.dmtf.org/standards/cim_spec_v22/ 2407 [10] Distributed Management Task Force, Inc., "DMTF LDAP Schema for the 2408 CIM v2.5 Core Information Model", May 21, 2001. This document 2409 is available on the following DMTF web page: 2410 http://www.dmtf.org/var/release/DEN/DSP0123.pdf 2412 [11] Wahl, M., " A Summary of the X.500(96) User Schema for use with 2413 LDAPv3", RFC 2256, December 1997. 2415 11. Authors' Addresses 2417 John Strassner 2418 Intelliden Corporation 2419 90 South Cascade Avenue 2420 Colorado Springs, CO 80903 2421 Phone: +1.719.785.0648 2422 Fax: +1.719.785.0644 2423 E-mail: john.strassner@intelliden.com 2425 Ed Ellesson 2426 LongBoard, Inc. 2427 2505 Meridian Pkwy, #100 2428 Durham, NC 27713 2429 Phone: +1 919-361-3230 2430 E-mail: eellesson@lboard.com 2432 Bob Moore 2433 IBM Corporation, BRQA/502 2434 4205 S. Miami Blvd. 2435 Research Triangle Park, NC 27709 2436 Phone: +1 919-254-4436 2437 Fax: +1 919-254-6243 2438 E-mail: remoore@us.ibm.com 2440 Ryan Moats 2441 Lemur Networks, Inc. 2442 15621 Drexel Circle 2443 Omaha, NE 68135 2444 USA 2445 Phone: +1-402-894-9456 2446 E-mail: moats@tconl.com 2448 12. Full Copyright Statement 2450 Copyright (C) The Internet Society (2001). All Rights Reserved. 2452 This document and translations of it may be copied and furnished to 2453 others, and derivative works that comment on or otherwise explain it or 2454 assist in its implementation may be prepared, copied, published and 2455 distributed, in whole or in part, without restriction of any kind, 2456 provided that the above copyright notice and this paragraph are included 2457 on all such copies and derivative works. However, this document itself 2458 may not be modified in any way, such as by removing the copyright notice 2459 or references to the Internet Society or other Internet organizations, 2460 except as needed for the purpose of developing Internet standards in 2461 which case the procedures for copyrights defined in the Internet 2462 Standards process must be followed, or as required to translate it into 2463 languages other than English. 2465 The limited permissions granted above are perpetual and will not be 2466 revoked by the Internet Society or its successors or assigns. 2468 This document and the information contained herein is provided on an "AS 2469 IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK 2470 FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT 2471 LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT 2472 INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR 2473 FITNESS FOR A PARTICULAR PURPOSE. 2475 13. Appendix: Constructing the Value of orderedCIMKeys 2477 This appendix is non-normative, and is included in this document as a 2478 guide to implementers that wish to exchange information between CIM 2479 schemata and LDAP schemata. 2481 Within a CIM name space, the naming is basically flat; all instances are 2482 identified by the values of their key properties, and each combination 2483 of key values must be unique. A limited form of hierarchical naming is 2484 available in CIM, however, by using weak associations: since a weak 2485 association involves propagation of key properties and their values from 2486 the superior object to the subordinate one, the subordinate object can 2487 be thought of as being named "under" the superior object. Once they 2488 have been propagated, however, propagated key properties and their 2489 values function in exactly the same way that native key properties and 2490 their values do in identifying a CIM instance. 2492 The CIM mapping document [10] introduces a special attribute, 2493 orderedCIMKeys, to help map from the CIM_ManagedElement class to the 2494 LDAP class dlm1ManagedElement. This attribute SHOULD only be used in an 2495 environment where it is necessary to map between an LDAP-accessible 2496 directory and a CIM repository. For an LDAP environment, other LDAP 2497 naming attributes are defined (i.e., cn and a class-specific naming 2498 attribute) that SHOULD be used instead. 2500 The role of orderedCIMKeys is to represent the information necessary to 2501 correlate an entry in an LDAP-accessible directory with an instance in a 2502 CIM name space. Depending on how naming of CIM-related entries is 2503 handled in an LDAP directory, the value of orderedCIMKeys represents one 2504 of two things: 2506 - If the DIT hierarchy does not mirror the "weakness hierarchy" of 2507 the CIM name space, then orderedCIMKeys represents all the 2508 keys of the CIM instance, both native and propagated. 2509 - If the DIT hierarchy does mirror the "weakness hierarchy" of the 2510 CIM name space, then orderedCIMKeys may represent either all the 2511 keys of the instance, or only the native keys. 2513 Regardless of which of these alternatives is taken, the syntax of 2514 orderedCIMKeys is the same - a DirectoryString of the form 2516 .=[,=]* 2518 where the = elements are ordered by the names of the key 2519 properties, according to the collating sequence for US ASCII. The only 2520 spaces allowed in the DirectoryString are those that fall within a 2521 element. As with alphabetizing the key properties, the goal of 2522 suppressing the spaces is once again to make the results of string 2523 operations predictable. 2525 The values of the elements are derived from the various CIM 2526 syntaxes according to a grammar specified in [9].