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diff --git a/doc/rfc/rfc3060.txt b/doc/rfc/rfc3060.txt new file mode 100644 index 0000000..95f13ef --- /dev/null +++ b/doc/rfc/rfc3060.txt @@ -0,0 +1,5603 @@ + + + + + + +Network Working Group B. Moore +Request for Comments: 3060 IBM +Category: Standards Track E. Ellesson + LongBoard, Inc. + J. Strassner + A. Westerinen + Cisco Systems + February 2001 + + + Policy Core Information Model -- Version 1 Specification + +Status of this Memo + + This document specifies an Internet standards track protocol for the + Internet community, and requests discussion and suggestions for + improvements. Please refer to the current edition of the "Internet + Official Protocol Standards" (STD 1) for the standardization state + and status of this protocol. Distribution of this memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2001). All Rights Reserved. + +Abstract + + This document presents the object-oriented information model for + representing policy information developed jointly in the IETF Policy + Framework WG and as extensions to the Common Information Model (CIM) + activity in the Distributed Management Task Force (DMTF). This model + defines two hierarchies of object classes: structural classes + representing policy information and control of policies, and + association classes that indicate how instances of the structural + classes are related to each other. Subsequent documents will define + mappings of this information model to various concrete + implementations, for example, to a directory that uses LDAPv3 as its + access protocol. + +Table of Contents + + 1. Introduction.................................................... 4 + 2. Modeling Policies............................................... 5 + 2.1. Policy Scope............................................... 8 + 2.2. Declarative versus Procedural Model........................ 8 + 3. Overview of the Policy Core Information Model.................. 10 + 4. Inheritance Hierarchies for the Policy Core Information Model.. 13 + 4.1. Implications of CIM Inheritance........................... 15 + 5. Details of the Model........................................... 15 + + + +Moore, et al. Standards Track [Page 1] + +RFC 3060 Policy Core Information Model February 2001 + + + 5.1. Reusable versus Rule-Specific Conditions and Actions...... 15 + 5.2. Roles..................................................... 17 + 5.2.1. Roles and Role Combinations............................. 17 + 5.2.2. The PolicyRoles Property................................ 21 + 5.3. Local Time and UTC Time in PolicyTimePeriodConditions..... 21 + 5.4. CIM Data Types............................................ 23 + 5.5. Comparison between CIM and LDAP Class Specifications...... 24 + 6. Class Definitions.............................................. 25 + 6.1. The Abstract Class "Policy"............................... 25 + 6.1.1. The Property "CommonName (CN)".......................... 26 + 6.1.2. The Multi-valued Property "PolicyKeywords".............. 26 + 6.1.3. The Property "Caption" (Inherited from ManagedElement).. 27 + 6.1.4. The Property "Description" (Inherited from + ManagedElement)......................................... 27 + 6.2. The Class "PolicyGroup"................................... 27 + 6.3. The Class "PolicyRule".................................... 29 + 6.3.1. The Property "Enabled".................................. 31 + 6.3.2. The Property "ConditionListType"........................ 31 + 6.3.3. The Property "RuleUsage"................................ 31 + 6.3.4. The Property "Priority"................................. 32 + 6.3.5. The Property "Mandatory"................................ 32 + 6.3.6. The Property "SequencedActions"......................... 33 + 6.3.7. The Multi-valued Property "PolicyRoles"................. 33 + 6.4. The Abstract Class "PolicyCondition"...................... 34 + 6.5. The Class "PolicyTimePeriodCondition"..................... 36 + 6.5.1. The Property "TimePeriod"............................... 38 + 6.5.2. The Property "MonthOfYearMask".......................... 39 + 6.5.3. The Property "DayOfMonthMask"........................... 39 + 6.5.4. The Property "DayOfWeekMask"............................ 40 + 6.5.5. The Property "TimeOfDayMask"............................ 41 + 6.5.6. The Property "LocalOrUtcTime"........................... 42 + 6.6. The Class "VendorPolicyCondition"......................... 42 + 6.6.1. The Multi-valued Property "Constraint".................. 43 + 6.6.2. The Property "ConstraintEncoding"....................... 43 + 6.7. The Abstract Class "PolicyAction"......................... 44 + 6.8. The Class "VendorPolicyAction"............................ 45 + 6.8.1. The Multi-valued Property "ActionData".................. 45 + 6.8.2. The Property "ActionEncoding"........................... 46 + 6.9. The Class "PolicyRepository".............................. 46 + 7. Association and Aggregation Definitions........................ 46 + 7.1. Associations.............................................. 47 + 7.2. Aggregations.............................................. 47 + 7.3. The Abstract Aggregation "PolicyComponent................. 47 + 7.4. The Aggregation "PolicyGroupInPolicyGroup"................ 47 + 7.4.1. The Reference "GroupComponent".......................... 48 + 7.4.2. The Reference "PartComponent"........................... 48 + 7.5. The Aggregation "PolicyRuleInPolicyGroup"................. 48 + 7.5.1. The Reference "GroupComponent".......................... 49 + + + +Moore, et al. Standards Track [Page 2] + +RFC 3060 Policy Core Information Model February 2001 + + + 7.5.2. The Reference "PartComponent"........................... 49 + 7.6. The Aggregation "PolicyConditionInPolicyRule"............. 49 + 7.6.1. The Reference "GroupComponent".......................... 50 + 7.6.2. The Reference "PartComponent"........................... 50 + 7.6.3. The Property "GroupNumber".............................. 50 + 7.6.4. The Property "ConditionNegated"......................... 51 + 7.7. The Aggregation "PolicyRuleValidityPeriod"................ 51 + 7.7.1. The Reference "GroupComponent".......................... 52 + 7.7.2. The Reference "PartComponent"........................... 52 + 7.8. The Aggregation "PolicyActionInPolicyRule"................ 52 + 7.8.1. The Reference "GroupComponent".......................... 53 + 7.8.2. The Reference "PartComponent"........................... 53 + 7.8.3. The Property "ActionOrder".............................. 53 + 7.9. The Abstract Association "PolicyInSystem"................. 54 + 7.10. The Weak Association "PolicyGroupInSystem"............... 55 + 7.10.1. The Reference "Antecedent"............................. 55 + 7.10.2. The Reference "Dependent".............................. 55 + 7.11. The Weak Association "PolicyRuleInSystem"................ 56 + 7.11.1. The Reference "Antecedent"............................. 56 + 7.11.2. The Reference "Dependent".............................. 56 + 7.12. The Association "PolicyConditionInPolicyRepository"...... 56 + 7.12.1. The Reference "Antecedent"............................. 57 + 7.12.2. The Reference "Dependent".............................. 57 + 7.13. The Association "PolicyActionInPolicyRepository"......... 57 + 7.13.1. The Reference "Antecedent"............................. 58 + 7.13.2. The Reference "Dependent".............................. 58 + 7.14. The Aggregation "PolicyRepositoryInPolicyRepository"..... 58 + 7.14.1. The Reference "GroupComponent"......................... 58 + 7.14.2. The Reference "PartComponent".......................... 59 + 8. Intellectual Property.......................................... 59 + 9. Acknowledgements............................................... 59 + 10. Security Considerations....................................... 60 + 11. References.................................................... 62 + 12. Authors' Addresses............................................ 64 + 13. Appendix A: Class Identification in a Native CIM + Implementation................................................ 65 + 13.1. Naming Instances of PolicyGroup and PolicyRule........... 65 + 13.1.1. PolicyGroup's CIM Keys................................. 65 + 13.1.2. PolicyRule's CIM Keys.................................. 66 + 13.2. Naming Instances of PolicyCondition and Its Subclasses... 67 + 13.2.1. PolicyCondition's CIM Keys............................. 69 + 13.3. Naming Instances of PolicyAction and Its Subclasses...... 71 + 13.4. Naming Instances of PolicyRepository..................... 72 + 13.5. Role of the CreationClassName Property in Naming......... 73 + 13.6. Object References........................................ 73 + 14. Appendix B: The Core Policy MOF.............................. 75 + 15. Full Copyright Statement..................................... 100 + + + + +Moore, et al. Standards Track [Page 3] + +RFC 3060 Policy Core Information Model February 2001 + + +1. Introduction + + This document presents the object-oriented information model for + representing policy information currently under joint development in + the IETF Policy Framework WG and as extensions to the Common + Information Model (CIM) activity in the Distributed Management Task + Force (DMTF). This model defines two hierarchies of object classes: + structural classes representing policy information and control of + policies, and association classes that indicate how instances of the + structural classes are related to each other. Subsequent documents + will define mappings of this information model to various concrete + implementations, for example, to a directory that uses LDAPv3 as its + access protocol. The components of the CIM schema are available via + the following URL: http://www.dmtf.org/spec/cims.html [1]. + + The policy classes and associations defined in this model are + sufficiently generic to allow them to represent policies related to + anything. However, it is expected that their initial application in + the IETF will be for representing policies related to QoS (DiffServ + and IntServ) and to IPSec. Policy models for application-specific + areas such as these may extend the Core Model in several ways. The + preferred way is to use the PolicyGroup, PolicyRule, and + PolicyTimePeriodCondition classes directly, as a foundation for + representing and communicating policy information. Then, specific + subclasses derived from PolicyCondition and PolicyAction can capture + application-specific definitions of conditions and actions of + policies. + + Two subclasses, VendorPolicyCondition and VendorPolicyAction, are + also included in this document, to provide a standard extension + mechanism for vendor-specific extensions to the Policy Core + Information Model. + + This document fits into the overall framework for representing, + deploying, and managing policies being developed by the Policy + Framework Working Group. It traces its origins to work that was + originally done for the Directory-enabled Networks (DEN) + specification, reference [5]. Work on the DEN specification by the + DEN Ad-Hoc Working Group itself has been completed. Further work to + standardize the models contained in it will be the responsibility of + selected working groups of the CIM effort in the Distributed + Management Task Force (DMTF). DMTF standardization of the core + policy model is the responsibility of the SLA Policy working group in + the DMTF. + + + + + + + +Moore, et al. Standards Track [Page 4] + +RFC 3060 Policy Core Information Model February 2001 + + + This document is organized in the following manner: + + o Section 2 provides a general overview of policies and how they are + modeled. + + o Section 3 presents a high-level overview of the classes and + associations comprising the Policy Core Information Model. + + o The remainder of the document presents the detailed specifications + for each of the classes and associations. + + o Appendix A overviews naming for native CIM implementations. Other + mappings, such as LDAPv3, will have their own naming mechanisms. + + o Appendix B reproduces the DMTF's Core Policy MOF specification. + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in RFC 2119, reference + [3]. + +2. Modeling Policies + + The classes comprising the Policy Core Information Model are intended + to serve as an extensible class hierarchy (through specialization) + for defining policy objects that enable application developers, + network administrators, and policy administrators to represent + policies of different types. + + One way to think of a policy-controlled network is to first model the + network as a state machine and then use policy to control which state + a policy-controlled device should be in or is allowed to be in at any + given time. Given this approach, policy is applied using a set of + policy rules. Each policy rule consists of a set of conditions and a + set of actions. Policy rules may be aggregated into policy groups. + These groups may be nested, to represent a hierarchy of policies. + + The set of conditions associated with a policy rule specifies when + the policy rule is applicable. The set of conditions can be + expressed as either an ORed set of ANDed sets of condition statements + or an ANDed set of ORed sets of statements. Individual condition + statements can also be negated. These combinations are termed, + respectively, Disjunctive Normal Form (DNF) and Conjunctive Normal + Form (CNF) for the conditions. + + If the set of conditions associated with a policy rule evaluates to + TRUE, then a set of actions that either maintain the current state of + the object or transition the object to a new state may be executed. + + + +Moore, et al. Standards Track [Page 5] + +RFC 3060 Policy Core Information Model February 2001 + + + For the set of actions associated with a policy rule, it is possible + to specify an order of execution, as well as an indication of whether + the order is required or merely recommended. It is also possible to + indicate that the order in which the actions are executed does not + matter. + + Policy rules themselves can be prioritized. One common reason for + doing this is to express an overall policy that has a general case + with a few specific exceptions. + + For example, a general QoS policy rule might specify that traffic + originating from members of the engineering group is to get Bronze + Service. A second policy rule might express an exception: traffic + originating from John, a specific member of the engineering group, is + to get Gold Service. Since traffic originating from John satisfies + the conditions of both policy rules, and since the actions associated + with the two rules are incompatible, a priority needs to be + established. By giving the second rule (the exception) a higher + priority than the first rule (the general case), a policy + administrator can get the desired effect: traffic originating from + John gets Gold Service, and traffic originating from all the other + members of the engineering group gets Bronze Service. + + Policies can either be used in a stand-alone fashion or aggregated + into policy groups to perform more elaborate functions. Stand-alone + policies are called policy rules. Policy groups are aggregations of + policy rules, or aggregations of policy groups, but not both. Policy + groups can model intricate interactions between objects that have + complex interdependencies. Examples of this include a sophisticated + user logon policy that sets up application access, security, and + reconfigures network connections based on a combination of user + identity, network location, logon method and time of day. A policy + group represents a unit of reusability and manageability in that its + management is handled by an identifiable group of administrators and + its policy rules would be consistently applied + + Stand-alone policies are those that can be expressed in a simple + statement. They can be represented effectively in schemata or MIBs. + Examples of this are VLAN assignments, simple YES/NO QoS requests, + and IP address allocations. A specific design goal of this model is + to support both stand-alone and aggregated policies. + + Policy groups and rules can be classified by their purpose and + intent. This classification is useful in querying or grouping policy + rules. It indicates whether the policy is used to motivate when or + how an action occurs, or to characterize services (that can then be + used, for example, to bind clients to network services). Describing + each of these concepts in more detail, + + + +Moore, et al. Standards Track [Page 6] + +RFC 3060 Policy Core Information Model February 2001 + + + o Motivational Policies are solely targeted at whether or how a + policy's goal is accomplished. Configuration and Usage Policies + are specific kinds of Motivational Policies. Another example is + the scheduling of file backup based on disk write activity from + 8am to 3pm, M-F. + + o Configuration Policies define the default (or generic) setup of a + managed entity (for example, a network service). Examples of + Configuration Policies are the setup of a network forwarding + service or a network-hosted print queue. + + o Installation Policies define what can and cannot be put on a + system or component, as well as the configuration of the + mechanisms that perform the install. Installation policies + typically represent specific administrative permissions, and can + also represent dependencies between different components (e.g., to + complete the installation of component A, components B and C must + be previously successfully installed or uninstalled). + + o Error and Event Policies. For example, if a device fails between + 8am and 9pm, call the system administrator, otherwise call the + Help Desk. + + o Usage Policies control the selection and configuration of entities + based on specific "usage" data. Configuration Policies can be + modified or simply re-applied by Usage Policies. Examples of + Usage Policies include upgrading network forwarding services after + a user is verified to be a member of a "gold" service group, or + reconfiguring a printer to be able to handle the next job in its + queue. + + o Security Policies deal with verifying that the client is actually + who the client purports to be, permitting or denying access to + resources, selecting and applying appropriate authentication + mechanisms, and performing accounting and auditing of resources. + + o Service Policies characterize network and other services (not use + them). For example, all wide-area backbone interfaces shall use a + specific type of queuing. + + Service policies describe services available in the network. + Usage policies describe the particular binding of a client of the + network to services available in the network. + + These categories are represented in the Policy Core Information Model + by special values defined for the PolicyKeywords property of the + abstract class Policy. + + + + +Moore, et al. Standards Track [Page 7] + +RFC 3060 Policy Core Information Model February 2001 + + +2.1. Policy Scope + + Policies represent business goals and objectives. A translation must + be made between these goals and objectives and their realization in + the network. An example of this could be a Service Level Agreement + (SLA), and its objectives and metrics (Service Level Objectives, or + SLOs), that are used to specify services that the network will + provide for a given client. The SLA will usually be written in + high-level business terminology. SLOs address more specific metrics + in support of the SLA. These high-level descriptions of network + services and metrics must be translated into lower-level, but also + vendor-and device-independent specifications. The Policy Core + Information Model classes are intended to serve as the foundation for + these lower-level, vendor- and device-independent specifications. + + It is envisioned that the definition of the Policy Core Informational + Model in this document is generic in nature and is applicable to + Quality of Service (QoS), to non-QoS networking applications (e.g., + DHCP and IPSec), and to non-networking applications (e.g., backup + policies, auditing access, etc.). + +2.2. Declarative versus Procedural Model + + The design of the Policy Core Information Model is influenced by a + declarative, not procedural, approach. More formally, a declarative + language is used to describe relational and functional languages. + Declarative languages describe relationships between variables in + terms of functions or inference rules, to which the interpreter or + compiler can apply a fixed algorithm in order to produce a result. + An imperative (or procedural) language specifies an explicit sequence + of steps to follow in order to produce a result. + + It is important to note that this information model does not rule out + the use of procedural languages. Rather, it recognizes that both + declarative as well as procedural languages can be used to implement + policy. This information model is better viewed as being declarative + because the sequence of steps for doing the processing of declarative + statements tends to be left to the implementer. However, we have + provided the option of expressing the desired order of action + execution in this policy information model, and for expressing + whether the order is mandatory or not. In addition, rather than + trying to define algorithms or sets of instructions or steps that + must be followed by a policy rule, we instead define a set of modular + building blocks and relationships that can be used in a declarative + or procedural fashion to define policies. + + + + + + +Moore, et al. Standards Track [Page 8] + +RFC 3060 Policy Core Information Model February 2001 + + + Compare this to a strictly procedural model. Taking such an approach + would require that we specify the condition testing sequence, and the + action execution sequence, in the policy repository itself. This + would, indeed, constrain the implementer. This is why the policy + model is characterized as a declarative one. That is, the + information model defines a set of attributes, and a set of entities + that contain these attributes. However, it does NOT define either + the algorithm to produce a result using the attributes or an explicit + sequence of steps to produce a result. + + There are several design considerations and trade-offs to make in + this respect. + + 1. On the one hand, we would like a policy definition language to be + reasonably human-friendly for ease of definitions and diagnostics. + On the other hand, given the diversity of devices (in terms of + their processing capabilities) which could act as policy decision + points, we would like to keep the language somewhat machine- + friendly. That is, it should be relatively simple to automate the + parsing and processing of the language in network elements. The + approach taken is to provide a set of classes and attributes that + can be combined in either a declarative or procedural approach to + express policies that manage network elements and services. The + key point is to avoid trying to standardize rules or sets of steps + to be followed in defining a policy. These must be left up to an + implementation. Interoperability is achieved by standardizing the + building blocks that are used to represent policy data and + information. + + 2. An important decision to make is the semantic style of the + representation of the information. + + The declarative approach that we are describing falls short of + being a "true" declarative model. Such a model would also specify + the algorithms used to combine the information and policy rules to + achieve particular behavior. We avoid specifying algorithms for + the same reason that we avoid specifying sets of steps to be + followed in a policy rule. However, the design of the information + model more closely follows that of a declarative language, and may + be easier to understand if such a conceptual model is used. This + leads to our third point, acknowledging a lack of "completeness" + and instead relying on presenting information that the policy + processing entity will work with. + + 3. It is important to control the complexity of the specification, + trading off richness of expression of data in the core information + model for ease of implementation and use. It is important to + acknowledge the collective lack of experience in the field + + + +Moore, et al. Standards Track [Page 9] + +RFC 3060 Policy Core Information Model February 2001 + + + regarding policies to control and manage network services and + hence avoid the temptation of aiming for "completeness". We + should instead strive to facilitate definition of a set of common + policies that customers require today (e.g., VPN and QoS) and + allow migration paths towards supporting complex policies as + customer needs and our understanding of these policies evolve with + experience. Specifically, in the context of the declarative style + language discussed above, it is important to avoid having full + blown predicate calculus as the language, as it would render many + important problems such as consistency checking and policy + decision point algorithms intractable. It is useful to consider a + reasonably constrained language from these perspectives. + + The Policy Core Information Model strikes a balance between + complexity and lack of power by using the well understood logical + concepts of Disjunctive Normal Form and Conjunctive Normal Form for + combining simple policy conditions into more complex ones. + +3. Overview of the Policy Core Information Model + + The following diagram provides an overview of the five central + classes comprising the Policy Core Information Model, their + associations to each other, and their associations to other classes + in the overall CIM model. Note that the abstract class Policy and + the two extension classes VendorPolicyCondition and + VendorPolicyAction are not shown. + + NOTE: For cardinalities, "*" is an abbreviation for "0..n". + + + + + + + + + + + + + + + + + + + + + + + +Moore, et al. Standards Track [Page 10] + +RFC 3060 Policy Core Information Model February 2001 + + + +-----------+ + | System | + ..... +--^-----^--+ ..... + . . 1. 1. . . + *.(a).* .(b) .(c) *.(d).* + +--v---v---------+ . . +-v---v------------+ + | PolicyGroup <........ . | PolicyRepository | + | | w * . | | + +------^---------+ . +-----^---------^--+ + *. . 0..1 . 0..1 . + .(e) . .(f) .(g) + *. . . . + +------v------+ w * . . . + | <................. . . + | PolicyRule | . . + | | . . + | | . . + | <........................ . . + | |* (h) . . . + | | . . . + | | . . . + | | . . . + | | . . . + | | . . . + | | . . . + | | .* .* . + | | +---------v-------v--+ . + | | | PolicyCondition | . + | | *+--------------------+ . + | | (i) ^ . + | <.............. I . + | |* . I . + | | .* ^ . + | | +----v----------------------+ . + | | | PolicyTimePeriodCondition | . + | | +---------------------------+ . + | | (j) . + | <......................... . + | |* . . + | | .* . + | | +----------v---------+* . + | | | PolicyAction <....... + +-------------+ +--------------------+ + + Figure 1. Overview of the Core Policy Classes and Relationships + + + + + + +Moore, et al. Standards Track [Page 11] + +RFC 3060 Policy Core Information Model February 2001 + + + In this figure the boxes represent the classes, and the dotted arrows + represent the associations. The following associations appear: + + (a) PolicyGroupInPolicyGroup + + (b) PolicyGroupInSystem + + (c) PolicyRuleInSystem + + (d) PolicyRepositoryInPolicyRepository + + (e) PolicyRuleInPolicyGroup + + (f) PolicyConditionInPolicyRepository + + (g) PolicyActionInPolicyRepository + + (h) PolicyConditionInPolicyRule + + (i) PolicyRuleValidityPeriod + + (j) PolicyActionInPolicyRule + + An association always connects two classes. The "two" classes may, + however, be the same class, as is the case with the + PolicyGroupInPolicyGroup association, which represents the recursive + containment of PolicyGroups in other PolicyGroups. The + PolicyRepositoryInPolicyRepository association is recursive in the + same way. + + An association includes cardinalities for each of the related + classes. These cardinalities indicate how many instances of each + class may be related to an instance of the other class. For example, + the PolicyRuleInPolicyGroup association has the cardinality range "*' + (that is, "0..n") for both the PolicyGroup and PolicyRule classes. + These ranges are interpreted as follows: + + o The "*" written next to PolicyGroup indicates that a PolicyRule + may be related to no PolicyGroups, to one PolicyGroup, or to more + than one PolicyGroup via the PolicyRuleInPolicyGroup association. + In other words, a PolicyRule may be contained in no PolicyGroups, + in one PolicyGroups, or in more than one PolicyGroup. + + o The "*" written next to PolicyRule indicates that a PolicyGroup + may be related to no PolicyRules, to one PolicyRule, or to more + than one PolicyRule via the PolicyRuleInPolicyGroup association. + In other words, a PolicyGroup may contain no PolicyRules, one + PolicyRule, or more than one PolicyRule. + + + +Moore, et al. Standards Track [Page 12] + +RFC 3060 Policy Core Information Model February 2001 + + + The "w" written next to the PolicyGroupInSystem and + PolicyRuleInSystem indicates that these are what CIM terms + "aggregations with weak references", or more briefly, "weak + aggregations". A weak aggregation is simply an indication of a + naming scope. Thus these two aggregations indicate that an instance + of a PolicyGroup or PolicyRule is named within the scope of a System + object. A weak aggregation implicitly has the cardinality 1..1 at + the end opposite the 'w'. + + The associations shown in Figure 1 are discussed in more detail in + Section 7. + +4. Inheritance Hierarchies for the Policy Core Information Model + + The following diagram illustrates the inheritance hierarchy for the + core policy classes: + + ManagedElement (abstract) + | + +--Policy (abstract) + | | + | +---PolicyGroup + | | + | +---PolicyRule + | | + | +---PolicyCondition (abstract) + | | | + | | +---PolicyTimePeriodCondition + | | | + | | +---VendorPolicyCondition + | | + | +---PolicyAction (abstract) + | | + | +---VendorPolicyAction + | + +--ManagedSystemElement (abstract) + | + +--LogicalElement (abstract) + | + +--System (abstract) + | + +--AdminDomain (abstract) + | + +---PolicyRepository + + Figure 2. Inheritance Hierarchy for the Core Policy Classes + + + + + +Moore, et al. Standards Track [Page 13] + +RFC 3060 Policy Core Information Model February 2001 + + + ManagedElement, ManagedSystemElement, LogicalElement, System, and + AdminDomain are defined in the CIM schema [1]. These classes are not + discussed in detail in this document. + + In CIM, associations are also modeled as classes. For the Policy + Core Information Model, the inheritance hierarchy for the + associations is as follows: + + [unrooted] + | + +---PolicyComponent (abstract) + | | + | +---PolicyGroupInPolicyGroup + | | + | +---PolicyRuleInPolicyGroup + | | + | +---PolicyConditionInPolicyRule + | | + | +---PolicyRuleValidityPeriod + | | + | +---PolicyActionInPolicyRule + | + +---Dependency (abstract) + | | + | +---PolicyInSystem (abstract) + | | + | +---PolicyGroupInSystem + | | + | +---PolicyRuleInSystem + | | + | +---PolicyConditionInPolicyRepository + | | + | +---PolicyActionInPolicyRepository + | + +---Component (abstract) + | + +---SystemComponent + | + +---PolicyRepositoryInPolicyRepository + + Figure 3. Inheritance Hierarchy for the Core Policy Associations + + The Dependency, Component, and SystemComponent associations are + defined in the CIM schema [1], and are not discussed further in this + document. + + + + + + +Moore, et al. Standards Track [Page 14] + +RFC 3060 Policy Core Information Model February 2001 + + +4.1. Implications of CIM Inheritance + + From the CIM schema, both properties and associations are inherited + to the Policy classes. For example, the class ManagedElement is + referenced in the associations Dependency, Statistics and + MemberOfCollection. And, the Dependency association is in turn + referenced in the DependencyContext association. At this very + abstract and high level in the inheritance hierarchy, the number of + these associations is very small and their semantics are quite + general. + + Many of these inherited associations convey additional semantics that + are not needed in understanding the Policy Core Information Model. + In fact, they are defined as OPTIONAL in the CIM Schema - since their + cardinality is "0..n" on all references. The PCIM document + specifically discusses what is necessary to support and instantiate. + For example, through subclassing of the Dependency association, the + exact Dependency semantics in PCIM are described. + + So, one may wonder what to do with these other inherited + associations. The answer is "ignore them unless you need them". You + would need them to describe additional information and semantics for + policy data. For example, it may be necessary to capture statistical + data for a PolicyRule (either for the rule in a repository or for + when it is executing in a policy system). Some examples of + statistical data for a rule are the number of times it was + downloaded, the number of times its conditions were evaluated, and + the number of times its actions were executed. (These types of data + would be described in a subclass of CIM_StatisticalInformation.) In + these cases, the Statistics association inherited from ManagedElement + to PolicyRule may be used to describe the tie between an instance of + a PolicyRule and the set of statistics for it. + +5. Details of the Model + + The following subsections discuss several specific issues related to + the Policy Core Information Model. + +5.1. Reusable versus Rule-Specific Conditions and Actions + + Policy conditions and policy actions can be partitioned into two + groups: ones associated with a single policy rule, and ones that are + reusable, in the sense that they may be associated with more than one + policy rule. Conditions and actions in the first group are termed + "rule-specific" conditions and actions; those in the second group are + characterized as "reusable". + + + + + +Moore, et al. Standards Track [Page 15] + +RFC 3060 Policy Core Information Model February 2001 + + + It is important to understand that the difference between a rule- + specific condition or action and a reusable one is based on the + intent of the policy administrator for the condition or action, + rather than on the current associations in which the condition or + action participates. Thus a reusable condition or action (that is, + one that a policy administrator has created to be reusable) may at + some point in time be associated with exactly one policy rule, + without thereby becoming rule-specific. + + There is no inherent difference between a rule-specific condition or + action and a reusable one. There are, however, differences in how + they are treated in a policy repository. For example, it's natural + to make the access permissions for a rule-specific condition or + action identical to those for the rule itself. It's also natural for + a rule-specific condition or action to be removed from the policy + repository at the same time the rule is. With reusable conditions + and actions, on the other hand, access permissions and existence + criteria must be expressible without reference to a policy rule. + + The preceding paragraph does not contain an exhaustive list of the + ways in which reusable and rule-specific conditions should be treated + differently. Its purpose is merely to justify making a semantic + distinction between rule-specific and reusable, and then reflecting + this distinction in the policy model itself. + + An issue is highlighted by reusable and rule-specific policy + conditions and policy actions: the lack of a programmatic capability + for expressing complex constraints involving multiple associations. + Taking PolicyCondition as an example, there are two aggregations to + look at. PolicyConditionInPolicyRule has the cardinality * at both + ends, and PolicyConditionInPolicyRepository has the cardinality * at + the PolicyCondition end, and [0..1] at the PolicyRepository end. + + Globally, these cardinalities are correct. However, there's more to + the story, which only becomes clear if we examine the cardinalities + separately for the two cases of a rule-specific PolicyCondition and a + reusable one. + + For a rule-specific PolicyCondition, the cardinality of + PolicyConditionInPolicyRule at the PolicyRule end is [1..1], rather + than [0..n] (recall that * is an abbreviation for [0..n]), since the + condition is unique to one policy rule. And the cardinality of + PolicyConditionInPolicyRepository at the PolicyRepository end is + [0..0], since the condition is not in the "re-usable" repository. + This is OK, since these are both subsets of the specified + cardinalities. + + + + + +Moore, et al. Standards Track [Page 16] + +RFC 3060 Policy Core Information Model February 2001 + + + For a reusable PolicyCondition, however, the cardinality of + PolicyConditionInPolicyRepository at the PolicyRepository end is + [1..1], since the condition must be in the repository. And, the + cardinality of PolicyConditionInPolicyRule at the PolicyRule end is + [0..n]. This last point is important: a reusable PolicyCondition + may be associated with 0, 1, or more than 1 PolicyRules, via exactly + the same association PolicyConditionInPolicyRule that binds a rule- + specific condition to its PolicyRule. + + Currently the only way to document constraints of this type is + textually. More formal methods for documenting complex constraints + are needed. + +5.2. Roles + +5.2.1. Roles and Role Combinations + + The concept of role is central to the design of the entire Policy + Framework. The idea behind roles is a simple one. Rather than + configuring, and then later having to update the configuration of, + hundreds or thousands (or more) of resources in a network, a policy + administrator assigns each resource to one or more roles, and then + specifies the policies for each of these roles. The Policy Framework + is then responsible for configuring each of the resources associated + with a role in such a way that it behaves according to the policies + specified for that role. When network behavior must be changed, the + policy administrator can perform a single update to the policy for a + role, and the Policy Framework will ensure that the necessary + configuration updates are performed on all the resources playing that + role. + + A more formal definition of a role is as follows: + + A role is a type of attribute that is used to select one or more + policies for a set of entities and/or components from among a much + larger set of available policies. + + Roles can be combined together. Here is a formal definition of a + "role- combination": + + A role-combination is a set of attributes that are used to select + one or more policies for a set of entities and/or components from + among a much larger set of available policies. As the examples + below illustrate, the selection process for a role combination + chooses policies associated with the combination itself, policies + associated with each of its sub-combinations, and policies + associated with each of the individual roles in the role- + combination. + + + +Moore, et al. Standards Track [Page 17] + +RFC 3060 Policy Core Information Model February 2001 + + + It is important to note that a role is more than an attribute. A + role defines a particular function of an entity or component that can + be used to identify particular behavior associated with that entity + or component. This difference is critical, and is most easily + understood by thinking of a role as a selector. When used in this + manner, one role (or role-combination) selects a different set of + policies than a different role (or role-combination) does. + + Roles and role-combinations are especially useful in selecting which + policies are applicable to a particular set of entities or components + when the policy repository can store thousands or hundreds of + thousands of policies. This use emphasizes the ability of the role + (or role- combination) to select the small subset of policies that + are applicable from a huge set of policies that are available. + + An example will illustrate how role-combinations actually work. + Suppose an installation has three roles defined for interfaces: + "Ethernet", "Campus", and "WAN". In the Policy Repository, some + policy rules could be associated with the role "Ethernet"; these + rules would apply to all Ethernet interfaces, regardless of whether + they were on the campus side or the WAN side. Other rules could be + associated with the role-combination "Campus"+"Ethernet"; these rules + would apply to the campus-side Ethernet interfaces, but not to those + on the WAN side. Finally, a third set of rules could be associated + with the role-combination "Ethernet"+"WAN"; these rules would apply + to the WAN-side Ethernet interfaces, but not to those on the campus + side. (The roles in a role-combination appear in alphabetical order + in these examples, because that is how they appear in the information + model.) + + If we have a specific interface A that's associated with the role- + combination "Ethernet"+"WAN", we see that it should have three + categories of policy rules applied to it: those for the "Ethernet" + role, those for the "WAN" role, and those for the role-combination + "Ethernet"+"WAN". Going one step further, if interface B is + associated with the role- combination "branch- + office"+"Ethernet"+"WAN", then B should have seven categories of + policy rules applied to it - those associated with the following + role-combinations: + + o "branch-office" + o "Ethernet" + o "WAN" + o "branch-office"+"Ethernet" + o "branch-office"+"WAN" + o "Ethernet"+"WAN" + o "branch-office"+"Ethernet"+"WAN". + + + + +Moore, et al. Standards Track [Page 18] + +RFC 3060 Policy Core Information Model February 2001 + + + In order to get all of the right policy rules for a resource like + interface B, a PDP must expand the single role-combination it + receives for B into this list of seven role-combinations, and then + retrieve from the Policy Repository the corresponding seven sets of + policy rules. Of course this example is unusually complicated: the + normal case will involve expanding a two-role combination into three + values identifying three sets of policy rules. + + Role-combinations also help to simplify somewhat the problem of + identifying conflicts between policy rules. With role-combinations, + it is possible for a policy administrator to specify one set of + policy rules for campus-side Ethernet interfaces, and a second set of + policy rules for WAN-side Ethernet interfaces, without having to + worry about conflicts between the two sets of rules. The policy + administrator simply "turns off" conflict detection for these two + sets of rules, by telling the policy management system that the roles + "Campus" and "WAN" are incompatible with each other. This indicates + that the role combination will never occur, and therefore conflicts + will never occur. In some cases the technology itself might identify + incompatible roles: "Ethernet" and "FrameRelay", for example. But + for less precise terms like "Campus" and "WAN", the policy + administrator must say whether they identify incompatible roles. + + When the policy administrator does this, there are three effects: + + 1. If an interface has assigned to it a role-combination involving + both "Campus" and "WAN", then the policy management system can + flag it as an error. + + 2. If a policy rule is associated with a role-combination involving + both "Campus" and "WAN", then the policy management system can + flag it as an error. + + 3. If the policy management system sees two policy rules, where one + is tied to the role "Campus" (or to a role-combination that + includes the role "Campus") and the other is tied to the role + "WAN" (or to a role- combination that includes the role "WAN"), + then the system does not need to look for conflicts between the + two policy rules: because of the incompatible roles, the two + rules cannot possibly conflict. + + + + + + + + + + + +Moore, et al. Standards Track [Page 19] + +RFC 3060 Policy Core Information Model February 2001 + + + +-------------------+ + | Policy Repository | + +-------------------+ + V + V retrieval of policy + V + +---------+ + | PDP/PEP | + +---------+ + v + v application of policy + v + +----------------+ + | Network Entity | + +----------------+ + + Figure 4. Retrieval and Application of a Policy + + Figure 4, which is introduced only as an example of how the Policy + Framework might be implemented by a collection of network + components, illustrates how roles operate within the Policy + Framework. Because the distinction between them is not important + to this discussion, the PDP and the PEP are combined in one box. + The points illustrated here apply equally well, though, to an + environment where the PDP and the PEP are implemented separately. + + A role represents a functional characteristic or capability of a + resource to which policies are applied. Examples of roles include + Backbone interface, Frame Relay interface, BGP-capable router, web + server, firewall, etc. The multiple roles assigned to a single + resource are combined to form that resource's role combination. + Role combinations are represented in the PCIM by values of the + PolicyRoles property in the PolicyRule class. A PDP uses policy + roles as follows to identify the policies it needs to be aware of: + + 1. The PDP learns in some way the list of roles that its PEPs + play. This information might be configured at the PDP, the + PEPs might supply it to the PDP, or the PDP might retrieve it + from a repository. + + 2. Using repository-specific means, the PDP determines where to + look for policy rules that might apply to it. + + 3. Using the roles and role-combinations it received from its PEPs + as indicated in the examples above, the PDP is able to locate + and retrieve the policy rules that are relevant to it. + + + + + +Moore, et al. Standards Track [Page 20] + +RFC 3060 Policy Core Information Model February 2001 + + +5.2.2. The PolicyRoles Property + + As indicated earlier, PolicyRoles is a property associated with a + policy rule. It is an array holding "role combinations" for the + policy rule, and correlates with the roles defined for a network + resource. Using the PolicyRoles property, it is possible to mark a + policy rule as applying, for example, to a Frame Relay interface or + to a backbone ATM interface. The PolicyRoles property take strings + of the form: + + <RoleName>[&&<RoleName>]* + + Each value of this property represents a role combination, including + the special case of a "combination" containing only one role. As the + format indicates, the role names in a role combination are ANDed + together to form a single selector. The multiple values of the + PolicyRoles property are logically ORed, to make it possible for a + policy rule to have multiple selectors. + + The individual role names in a role combination must appear in + alphabetical order (according to the collating sequence for UCS-2 + characters), to make the string matches work correctly. The role + names used in an environment are specified by the policy + administrator. + +5.3. Local Time and UTC Time in PolicyTimePeriodConditions + + An instance of PolicyTimePeriodCondition has up to five properties + that represent times: TimePeriod, MonthOfYearMask, DayOfMonthMask, + DayOfWeekMask, and TimeOfDayMask. All of the time-related properties + in an instance of PolicyTimePeriodCondition represent one of two + types of times: local time at the place where a policy rule is + applied, or UTC time. The property LocalOrUtcTime indicates which + time representation applies to an instance of + PolicyTimePeriodCondition. + + Since the PCIM provides only for local time and UTC time, a Policy + Management Tool that provides for other time representations (for + example, a fixed time at a particular location) will need to map from + these other representations to either local time or UTC time. An + example will illustrate the nature of this mapping. + + Suppose a policy rule is tied to the hours of operation for a Help + Desk: 0800 to 2000 Monday through Friday [US] Eastern Time. In + order to express these times in PolicyTimePeriodCondition, a + management tool must convert them to UTC times. (They are not local + times, because they refer to a single time interval worldwide, not to + intervals tied to the local clocks at the locations where the + + + +Moore, et al. Standards Track [Page 21] + +RFC 3060 Policy Core Information Model February 2001 + + + PolicyRule is being applied.) As reference [10] points out, mapping + from [US] Eastern Time to UTC time is not simply a matter of applying + an offset: the offset between [US] Eastern Time and UTC time + switches between -0500 and -0400 depending on whether Daylight + Savings Time is in effect in the US. + + Suppose the policy administrator's goal is to have a policy rule be + valid from 0800 until 1200 [US] Eastern Time on every Monday, within + the overall time period from the beginning of 2000 until the end of + 2001. The Policy Management Tool could either be configured with the + definition of what [US] Eastern Time means, or it could be configured + with knowledge of where to go to get this information. Reference + [10] contains further discussion of time zone definitions and where + they might reside. + + Armed with knowledge about [US] Eastern Time, the Policy Management + Tool would create however many instances of PolicyTimePeriodCondition + it needed to represent the desired intervals. Note that while there + is an increased number of PolicyTimePeriodCondition instances, there + is still just one PolicyRule, which is tied to all the + PolicyTimePeriodCondition instances via the aggregation + PolicyRuleValidityPeriod. Here are the first two of these instances: + + 1. TimePeriod: 20000101T050000/20000402T070000 + DayOfWeekMask: { Monday } + TimeOfDayMask: T130000/T170000 + LocalOrUtcTime: UTC + + 2. TimePeriod: 20000402T070000/20001029T070000 + DayOfWeekMask: { Monday } + TimeOfDayMask: T120000/T160000 + LocalOrUtcTime: UTC + + There would be three more similar instances, for winter 2000-2001, + summer 2001, and winter 2001 up through December 31. + + Had the example been chosen differently, there could have been even + more instances of PolicyTimePeriodCondition. If, for example, the + + time interval had been from 0800 - 2200 [US] Eastern Time on Mondays, + instance 1 above would have split into two instances: one with a UTC + time interval of T130000/T240000 on Mondays, and another with a UTC + time interval of T000000/T030000 on Tuesdays. So the end result + would have been ten instances of PolicyTimePeriodCondition, not five. + + By restricting PolicyTimePeriodCondition to local time and UTC time, + the PCIM places the difficult and expensive task of mapping from + "human" time representations to machine-friendly ones in the Policy + + + +Moore, et al. Standards Track [Page 22] + +RFC 3060 Policy Core Information Model February 2001 + + + Management Tool. Another approach would have been to place in + PolicyTimePeriodCondition a means of representing a named time zone, + such as [US] Eastern Time. This, however, would have passed the + difficult mapping responsibility down to the PDPs and PEPs. It is + better to have a mapping such as the one described above done once in + a Policy Management Tool, rather than having it done over and over in + each of the PDPs (and possibly PEPs) that need to apply a PolicyRule. + +5.4. CIM Data Types + + Since PCIM extends the CIM Schema, a correspondence between data + types used in both CIM and PCIM is needed. The following CIM data + types are used in the class definitions that follow in Sections 6 and + 7: + + o uint8 unsigned 8-bit integer + + o uint16 unsigned 16-bit integer + + o boolean Boolean + + o string UCS-2 string. + + Strings in CIM are stored as UCS-2 characters, where each character + is encoded in two octets. Thus string values may need to be + converted when moving between a CIM environment and one that uses a + different string encoding. For example, in an LDAP-accessible + directory, attributes of type DirectoryString are stored in UTF-8 + format. RFC 2279 [7] explains how to convert between these two + formats. + + When it is applied to a CIM string, a MaxLen value refers to the + maximum number of characters in the string, rather than to the + maximum number of octets. + + In addition to the CIM data types listed above, the association + classes in Section 7 use the following type: + + o <classname> ref strongly typed reference. + + There is one obvious omission from this list of CIM data types: + octet strings. This is because CIM treats octet strings as a derived + data type. There are two forms of octet strings in CIM - an ordered + uint8 array for single-valued strings, and a string array for multi- + valued properties. Both are described by adding an "OctetString" + qualifier (meta-data) to the property. This qualifier functions + exactly like an SMIv2 (SNMP) Textual Convention, refining the syntax + and semantics of the existing CIM data type. + + + +Moore, et al. Standards Track [Page 23] + +RFC 3060 Policy Core Information Model February 2001 + + + The first four numeric elements of both of the "OctetString" + representations are a length field. (The reason that the "numeric" + adjective is added to the previous sentence is that the string + property also includes '0' and 'x', as its first characters.) In + both cases, these 4 numeric elements (octets) are included in + calculating the length. For example, a single-valued octet string + property having the value X'7C' would be represented by the uint8 + array, X'00 00 00 05 7C'. + + The strings representing the individual values of a multi-valued + property qualified with the "OctetString" qualifier are constructed + similarly: + + 1. Take a value to be encoded as an octet string (we'll use X'7C' as + above), and prepend to it a four-octet length. The result is the + same, X'00 00 00 05 7C'. + + 2. Convert this to a character string by introducing '0' and 'x' at + the front, and removing all white space. Thus we have the 12- + character string "0x000000057C". This string is the value of one + of the array elements in the CIM string array. Since CIM uses the + UCS-2 character set, it will require 24 octets to encode this 12- + character string. + + Mappings of the PCIM to particular data models are not required to + follow this CIM technique of representing multi-valued octet strings + as length- prefixed character strings. In an LDAP mapping, for + example, it would be much more natural to simply use the Octet String + syntax, and omit the prepended length octets. + +5.5. Comparison between CIM and LDAP Class Specifications + + There are a number of differences between CIM and LDAP class + specifications. The ones that are relevant to the abbreviated class + specifications in this document are listed below. These items are + included here to help introduce the IETF community, which is already + familiar with LDAP, to CIM modeling, and by extension, to information + modeling in general. + + o Instead of LDAP's three class types (abstract, auxiliary, + structural), CIM has only two: abstract and instantiable. The + type of a CIM class is indicated by the Boolean qualifier + ABSTRACT. + + o CIM uses the term "property" for what LDAP terms an "attribute". + + + + + + +Moore, et al. Standards Track [Page 24] + +RFC 3060 Policy Core Information Model February 2001 + + + o CIM uses the array notation "[ ]" to indicate that a property is + multi-valued. CIM defines three types of arrays: bags (contents + are unordered, duplicates allowed), ordered bags (contents are + ordered but duplicates are allowed) and indexed arrays (contents + are ordered and no duplicates are allowed). + + o CIM classes and properties are identified by name, not by OID. + + o CIM classes use a different naming scheme for native + implementations, than LDAP. The CIM naming scheme is documented + in Appendix A since it is not critical to understanding the + information model, and only applies when communicating with a + native CIM implementation. + + o In LDAP, attribute definitions are global, and the same attribute + may appear in multiple classes. In CIM, a property is defined + within the scope of a single class definition. The property may + be inherited into subclasses of the class in which it is defined, + but otherwise it cannot appear in other classes. One side effect + of this difference is that CIM property names tend to be much + shorter than LDAP attribute names, since they are implicitly + scoped by the name of the class in which they are defined. + + There is also a notational convention that this document follows, to + improve readability. In CIM, all class and property names are + prefixed with the characters "CIM_". These prefixes have been + omitted throughout this document, with one exception regarding + naming, documented in Appendix A. + + For the complete definition of the CIM specification language, see + reference [2]. + +6. Class Definitions + + The following sections contain the definitions of the PCIM classes. + +6.1. The Abstract Class "Policy" + + The abstract class Policy collects several properties that may be + included in instances of any of the Core Policy classes (or their + subclasses). For convenience, the two properties that Policy + inherits from ManagedElement in the CIM schema are shown here as + well. + + + + + + + + +Moore, et al. Standards Track [Page 25] + +RFC 3060 Policy Core Information Model February 2001 + + + The class definition is as follows: + + NAME Policy + DESCRIPTION An abstract class with four properties for + describing a policy-related instance. + DERIVED FROM ManagedElement + ABSTRACT TRUE + PROPERTIES CommonName (CN) + PolicyKeywords[ ] + // Caption (inherited) + // Description (inherited) + +6.1.1. The Property "CommonName (CN)" + + The CN, or CommonName, property corresponds to the X.500 attribute + commonName (cn). In X.500 this property specifies one or more user- + friendly names (typically only one name) by which an object is + commonly known, names that conform to the naming conventions of the + country or culture with which the object is associated. In the CIM + model, however, the CommonName property is single-valued. + + NAME CN + DESCRIPTION A user-friendly name of a policy-related object. + SYNTAX string + +6.1.2. The Multi-valued Property "PolicyKeywords" + + This property provides a set of one or more keywords that a policy + administrator may use to assist in characterizing or categorizing a + policy object. Keywords are of one of two types: + + o Keywords defined in this document, or in documents that define + subclasses of the classes defined in this document. These + keywords provide a vendor-independent, installation-independent + way of characterizing policy objects. + + o Installation-dependent keywords for characterizing policy objects. + Examples include "Engineering", "Billing", and "Review in December + 2000". + + This document defines the following keywords: "UNKNOWN", + "CONFIGURATION", "USAGE", "SECURITY", "SERVICE", "MOTIVATIONAL", + "INSTALLATION", and "EVENT". These concepts were defined earlier in + Section 2. + + + + + + + +Moore, et al. Standards Track [Page 26] + +RFC 3060 Policy Core Information Model February 2001 + + + One additional keyword is defined: "POLICY". The role of this + keyword is to identify policy-related instances that would not + otherwise be identifiable as being related to policy. It may be + needed in some repository implementations. + + Documents that define subclasses of the Policy Core Information Model + classes SHOULD define additional keywords to characterize instances + of these subclasses. By convention, keywords defined in conjunction + with class definitions are in uppercase. Installation-defined + keywords can be in any case. + + The property definition is as follows: + + NAME PolicyKeywords + DESCRIPTION A set of keywords for characterizing /categorizing + policy objects. + SYNTAX string + +6.1.3. The Property "Caption" (Inherited from ManagedElement) + + This property provides a one-line description of a policy-related + object. + + NAME Caption + DESCRIPTION A one-line description of this policy-related object. + SYNTAX string + +6.1.4. The Property "Description" (Inherited from ManagedElement) + + This property provides a longer description than that provided by the + caption property. + + NAME Description + DESCRIPTION A long description of this policy-related object. + SYNTAX string + +6.2. The Class "PolicyGroup" + + This class is a generalized aggregation container. It enables either + PolicyRules or PolicyGroups to be aggregated in a single container. + Loops, including the degenerate case of a PolicyGroup that contains + itself, are not allowed when PolicyGroups contain other PolicyGroups. + + PolicyGroups and their nesting capabilities are shown in Figure 5 + below. Note that a PolicyGroup can nest other PolicyGroups, and + there is no restriction on the depth of the nesting in sibling + PolicyGroups. + + + + +Moore, et al. Standards Track [Page 27] + +RFC 3060 Policy Core Information Model February 2001 + + + +---------------------------------------------------+ + | PolicyGroup | + | | + | +--------------------+ +-----------------+ | + | | PolicyGroup A | | PolicyGroup X | | + | | | | | | + | | +----------------+ | ooo | | | + | | | PolicyGroup A1 | | | | | + | | +----------------+ | | | | + | +--------------------+ +-----------------+ | + +---------------------------------------------------+ + + Figure 5. Overview of the PolicyGroup class + + As a simple example, think of the highest level PolicyGroup shown in + Figure 5 above as a logon policy for US employees of a company. This + PolicyGroup may be called USEmployeeLogonPolicy, and may aggregate + several PolicyGroups that provide specialized rules per location. + Hence, PolicyGroup A in Figure 5 above may define logon rules for + employees on the West Coast, while another PolicyGroup might define + logon rules for the Midwest (e.g., PolicyGroup X), and so forth. + + Note also that the depth of each PolicyGroup does not need to be the + same. Thus, the WestCoast PolicyGroup might have several additional + layers of PolicyGroups defined for any of several reasons (different + locales, number of subnets, etc..). The PolicyRules are therefore + contained at n levels from the USEmployeeLogonPolicyGroup. Compare + this to the Midwest PolicyGroup (PolicyGroup X), which might directly + contain PolicyRules. + + The class definition for PolicyGroup is as follows: + + NAME PolicyGroup + DESCRIPTION A container for either a set of related + PolicyRules or a set of related PolicyGroups. + DERIVED FROM Policy + ABSTRACT FALSE + PROPERTIES NONE + + No properties are defined for this class since it inherits all its + properties from Policy. The class exists to aggregate PolicyRules or + other PolicyGroups. It is directly instantiable. In an + implementation, various key/identification properties MUST be + defined. The keys for a native CIM implementation are defined in + Appendix A, Section 13.1.1. Keys for an LDAP implementation will be + defined in the LDAP mapping of this information model [11]. + + + + + +Moore, et al. Standards Track [Page 28] + +RFC 3060 Policy Core Information Model February 2001 + + +6.3. The Class "PolicyRule" + + This class represents the "If Condition then Action" semantics + associated with a policy. A PolicyRule condition, in the most + general sense, is represented as either an ORed set of ANDed + conditions (Disjunctive Normal Form, or DNF) or an ANDed set of ORed + conditions (Conjunctive Normal Form, or CNF). Individual conditions + may either be negated (NOT C) or unnegated (C). The actions + specified by a PolicyRule are to be performed if and only if the + PolicyRule condition (whether it is represented in DNF or CNF) + evaluates to TRUE. + + The conditions and actions associated with a policy rule are modeled, + respectively, with subclasses of the classes PolicyCondition and + PolicyAction. These condition and action objects are tied to + instances of PolicyRule by the PolicyConditionInPolicyRule and + PolicyActionInPolicyRule aggregations. + + As illustrated above in Section 3, a policy rule may also be + associated with one or more policy time periods, indicating the + schedule according to which the policy rule is active and inactive. + In this case it is the PolicyRuleValidityPeriod aggregation that + provides the linkage. + + A policy rule is illustrated conceptually in Figure 6. below. + + +------------------------------------------------+ + | PolicyRule | + | | + | +--------------------+ +-----------------+ | + | | PolicyCondition(s) | | PolicyAction(s) | | + | +--------------------+ +-----------------+ | + | | + | +------------------------------+ | + | | PolicyTimePeriodCondition(s) | | + | +------------------------------+ | + +------------------------------------------------+ + + Figure 6. Overview of the PolicyRule Class + + The PolicyRule class uses the property ConditionListType, to indicate + whether the conditions for the rule are in DNF or CNF. The + PolicyConditionInPolicyRule aggregation contains two additional + properties to complete the representation of the rule's conditional + expression. The first of these properties is an integer to partition + the referenced conditions into one or more groups, and the second is + a Boolean to indicate whether a referenced condition is negated. An + + + + +Moore, et al. Standards Track [Page 29] + +RFC 3060 Policy Core Information Model February 2001 + + + example shows how ConditionListType and these two additional + properties provide a unique representation of a set of conditions in + either DNF or CNF. + + Suppose we have a PolicyRule that aggregates five PolicyConditions C1 + through C5, with the following values in the properties of the five + PolicyConditionInPolicyRule associations: + + C1: GroupNumber = 1, ConditionNegated = FALSE + C2: GroupNumber = 1, ConditionNegated = TRUE + C3: GroupNumber = 1, ConditionNegated = FALSE + C4: GroupNumber = 2, ConditionNegated = FALSE + C5: GroupNumber = 2, ConditionNegated = FALSE + + If ConditionListType = DNF, then the overall condition for the + PolicyRule is: + + (C1 AND (NOT C2) AND C3) OR (C4 AND C5) + + On the other hand, if ConditionListType = CNF, then the overall + condition for the PolicyRule is: + + (C1 OR (NOT C2) OR C3) AND (C4 OR C5) + + In both cases, there is an unambiguous specification of the overall + condition that is tested to determine whether to perform the actions + associated with the PolicyRule. + + The class definition is as follows: + + NAME PolicyRule + DESCRIPTION The central class for representing the "If Condition + then Action" semantics associated with a policy rule. + DERIVED FROM Policy + ABSTRACT FALSE + PROPERTIES Enabled + ConditionListType + RuleUsage + Priority + Mandatory + SequencedActions + PolicyRoles + + The PolicyRule class is directly instantiable. In an implementation, + various key/identification properties MUST be defined. The keys for + a native CIM implementation are defined in Appendix A, Section + 13.1.2. Keys for an LDAP implementation will be defined in the LDAP + mapping of this information model [11]. + + + +Moore, et al. Standards Track [Page 30] + +RFC 3060 Policy Core Information Model February 2001 + + +6.3.1. The Property "Enabled" + + This property indicates whether a policy rule is currently enabled, + from an administrative point of view. Its purpose is to allow a + policy administrator to enable or disable a policy rule without + having to add it to, or remove it from, the policy repository. + + The property also supports the value 'enabledForDebug'. When the + property has this value, the entity evaluating the policy + condition(s) is being told to evaluate the conditions for the policy + rule, but not to perform the actions if the conditions evaluate to + TRUE. This value serves as a debug vehicle when attempting to + determine what policies would execute in a particular scenario, + without taking any actions to change state during the debugging. + + The property definition is as follows: + + NAME Enabled + DESCRIPTION An enumeration indicating whether a policy rule is + administratively enabled, administratively disabled, + or enabled for debug mode. + SYNTAX uint16 + VALUES enabled(1), disabled(2), enabledForDebug(3) + DEFAULT VALUE enabled(1) + +6.3.2. The Property "ConditionListType" + + This property is used to specify whether the list of policy + conditions associated with this policy rule is in disjunctive normal + form (DNF) or conjunctive normal form (CNF). If this property is not + present, the list type defaults to DNF. The property definition is + as follows: + + NAME ConditionListType + DESCRIPTION Indicates whether the list of policy conditions + associated with this policy rule is in disjunctive + normal form (DNF) or conjunctive normal form (CNF). + SYNTAX uint16 + VALUES DNF(1), CNF(2) + DEFAULT VALUE DNF(1) + +6.3.3. The Property "RuleUsage" + + This property is a free-form string that recommends how this policy + should be used. The property definition is as follows: + + + + + + +Moore, et al. Standards Track [Page 31] + +RFC 3060 Policy Core Information Model February 2001 + + + NAME RuleUsage + DESCRIPTION This property is used to provide guidelines on + how this policy should be used. + SYNTAX string + +6.3.4. The Property "Priority" + + This property provides a non-negative integer for prioritizing policy + rules relative to each other. Larger integer values indicate higher + priority. Since one purpose of this property is to allow specific, + ad hoc policy rules to temporarily override established policy rules, + an instance that has this property set has a higher priority than all + instances that use or set the default value of zero. + + Prioritization among policy rules provides a basic mechanism for + resolving policy conflicts. + + The property definition is as follows: + + NAME Priority + DESCRIPTION A non-negative integer for prioritizing this + PolicyRule relative to other PolicyRules. A larger + value indicates a higher priority. + SYNTAX uint16 + DEFAULT VALUE 0 + +6.3.5. The Property "Mandatory" + + This property indicates whether evaluation (and possibly action + execution) of a PolicyRule is mandatory or not. Its concept is + similar to the ability to mark packets for delivery or possible + discard, based on network traffic and device load. + + The evaluation of a PolicyRule MUST be attempted if the Mandatory + property value is TRUE. If the Mandatory property value of a + PolicyRule is FALSE, then the evaluation of the rule is "best effort" + and MAY be ignored. + + The property definition is as follows: + + NAME Mandatory + DESCRIPTION A flag indicating that the evaluation of the + PolicyConditions and execution of PolicyActions + (if the condition list evaluates to TRUE) is + required. + SYNTAX boolean + DEFAULT VALUE TRUE + + + + +Moore, et al. Standards Track [Page 32] + +RFC 3060 Policy Core Information Model February 2001 + + +6.3.6. The Property "SequencedActions" + + This property gives a policy administrator a way of specifying how + the ordering of the policy actions associated with this PolicyRule is + to be interpreted. Three values are supported: + + o mandatory(1): Do the actions in the indicated order, or don't do + them at all. + + o recommended(2): Do the actions in the indicated order if you can, + but if you can't do them in this order, do them in another order + if you can. + + o dontCare(3): Do them -- I don't care about the order. + + When error / event reporting is addressed for the Policy Framework, + suitable codes will be defined for reporting that a set of actions + could not be performed in an order specified as mandatory (and thus + were not performed at all), that a set of actions could not be + performed in a recommended order (and moreover could not be performed + in any order), or that a set of actions could not be performed in a + recommended order (but were performed in a different order). The + property definition is as follows: + + NAME SequencedActions + DESCRIPTION An enumeration indicating how to interpret the + action ordering indicated via the + PolicyActionInPolicyRule aggregation. + SYNTAX uint16 + VALUES mandatory(1), recommended(2), dontCare(3) + DEFAULT VALUE dontCare(3) + +6.3.7. The Multi-valued Property "PolicyRoles" + + This property represents the roles and role combinations associated + with a policy rule. Each value represents one role combination. + Since this is a multi-valued property, more than one role combination + can be associated with a single policy rule. Each value is a string + of the form + + <RoleName>[&&<RoleName>]* + + where the individual role names appear in alphabetical order + (according to the collating sequence for UCS-2). The property + definition is as follows: + + + + + + +Moore, et al. Standards Track [Page 33] + +RFC 3060 Policy Core Information Model February 2001 + + + NAME PolicyRoles + DESCRIPTION A set of strings representing the roles and role + combinations associated with a policy rule. Each + value represents one role combination. + SYNTAX string + +6.4. The Abstract Class "PolicyCondition" + + The purpose of a policy condition is to determine whether or not the + set of actions (aggregated in the PolicyRule that the condition + applies to) should be executed or not. For the purposes of the + Policy Core Information Model, all that matters about an individual + PolicyCondition is that it evaluates to TRUE or FALSE. (The + individual PolicyConditions associated with a PolicyRule are combined + to form a compound expression in either DNF or CNF, but this is + accomplished via the ConditionListType property, discussed above, and + by the properties of the PolicyConditionInPolicyRule aggregation, + introduced above and discussed further in Section 7.6 below.) A + logical structure within an individual PolicyCondition may also be + introduced, but this would have to be done in a subclass of + PolicyCondition. + + Because it is general, the PolicyCondition class does not itself + contain any "real" conditions. These will be represented by + properties of the domain-specific subclasses of PolicyCondition. + + +---------------------------------------------------------------+ + | Policy Conditions in DNF | + | +-------------------------+ +-----------------------+ | + | | AND list | | AND list | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | | | PolicyCondition | | | + | | +-------------------+ | | +-----------------+ | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | ... | | PolicyCondition | | | + | | +-------------------+ | ORed | +-----------------+ | | + | | ... | | ... | | + | | ANDed | | ANDed | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | | | PolicyCondition | | | + | | +-------------------+ | | +-----------------+ | | + | +-------------------------+ +-----------------------+ | + +---------------------------------------------------------------+ + + Figure 7. Overview of Policy Conditions in DNF + + + + + + +Moore, et al. Standards Track [Page 34] + +RFC 3060 Policy Core Information Model February 2001 + + + This figure illustrates that when policy conditions are in DNF, there + are one or more sets of conditions that are ANDed together to form + AND lists. An AND list evaluates to TRUE if and only if all of its + constituent conditions evaluate to TRUE. The overall condition then + evaluates to TRUE if and only if at least one of its constituent AND + lists evaluates to TRUE. + + +---------------------------------------------------------------+ + | Policy Conditions in CNF | + | +-------------------------+ +-----------------------+ | + | | OR list | | OR list | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | | | PolicyCondition | | | + | | +-------------------+ | | +-----------------+ | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | ... | | PolicyCondition | | | + | | +-------------------+ | ANDed | +-----------------+ | | + | | ... | | ... | | + | | ORed | | ORed | | + | | +-------------------+ | | +-----------------+ | | + | | | PolicyCondition | | | | PolicyCondition | | | + | | +-------------------+ | | +-----------------+ | | + | +-------------------------+ +-----------------------+ | + +---------------------------------------------------------------+ + + Figure 8. Overview of Policy Conditions in CNF + + In this figure, the policy conditions are in CNF. Consequently, + there are one or more OR lists, each of which evaluates to TRUE if + and only if at least one of its constituent conditions evaluates to + TRUE. The overall condition then evaluates to TRUE if and only if + ALL of its constituent OR lists evaluate to TRUE. + + The class definition of PolicyCondition is as follows: + + NAME PolicyCondition + DESCRIPTION A class representing a rule-specific or reusable + policy condition to be evaluated in conjunction + with a policy rule. + DERIVED FROM Policy + ABSTRACT TRUE + PROPERTIES NONE + + No properties are defined for this class since it inherits all its + properties from Policy. The class exists as an abstract superclass + for domain-specific policy conditions, defined in subclasses. In an + implementation, various key/identification properties MUST be defined + for the class or its instantiable subclasses. The keys for a native + + + +Moore, et al. Standards Track [Page 35] + +RFC 3060 Policy Core Information Model February 2001 + + + CIM implementation are defined in Appendix A, Section 13.2. Keys for + an LDAP implementation will be defined in the LDAP mapping of this + information model [11]. + + When identifying and using the PolicyCondition class, it is necessary + to remember that a condition can be rule-specific or reusable. This + was discussed above in Section 5.1. The distinction between the two + types of policy conditions lies in the associations in which an + instance can participate, and in how the different instances are + named. Conceptually, a reusable policy condition resides in a policy + repository, and is named within the scope of that repository. On the + other hand, a rule-specific policy condition is, as the name + suggests, named within the scope of the single policy rule to which + it is related. + + The distinction between rule-specific and reusable PolicyConditions + affects the CIM naming, defined in Appendix A, and the LDAP mapping + [11]. + +6.5. The Class "PolicyTimePeriodCondition" + + This class provides a means of representing the time periods during + which a policy rule is valid, i.e., active. At all times that fall + outside these time periods, the policy rule has no effect. A policy + rule is treated as valid at all times if it does not specify a + PolicyTimePeriodCondition. + + In some cases a PDP may need to perform certain setup / cleanup + actions when a policy rule becomes active / inactive. For example, + sessions that were established while a policy rule was active might + need to be taken down when the rule becomes inactive. In other + cases, however, such sessions might be left up: in this case, the + effect of deactivating the policy rule would just be to prevent the + establishment of new sessions. Setup / cleanup behaviors on validity + period transitions are not currently addressed by the PCIM, and must + be specified in 'guideline' documents, or via subclasses of + PolicyRule, PolicyTimePeriodCondition or other concrete subclasses of + Policy. If such behaviors need to be under the control of the policy + administrator, then a mechanism to allow this control must also be + specified in the subclass. + + PolicyTimePeriodCondition is defined as a subclass of + PolicyCondition. This is to allow the inclusion of time-based + criteria in the AND/OR condition definitions for a PolicyRule. + + Instances of this class may have up to five properties identifying + time periods at different levels. The values of all the properties + present in an instance are ANDed together to determine the validity + + + +Moore, et al. Standards Track [Page 36] + +RFC 3060 Policy Core Information Model February 2001 + + + period(s) for the instance. For example, an instance with an overall + validity range of January 1, 2000 through December 31, 2000; a month + mask that selects March and April; a day-of-the-week mask that + selects Fridays; and a time of day range of 0800 through 1600 would + represent the following time periods: + + Friday, March 5, 2000, from 0800 through 1600; + Friday, March 12, 2000, from 0800 through 1600; + Friday, March 19, 2000, from 0800 through 1600; + Friday, March 26, 2000, from 0800 through 1600; + Friday, April 2, 2000, from 0800 through 1600; + Friday, April 9, 2000, from 0800 through 1600; + Friday, April 16, 2000, from 0800 through 1600; + Friday, April 23, 2000, from 0800 through 1600; + Friday, April 30, 2000, from 0800 through 1600. + + Properties not present in an instance of PolicyTimePeriodCondition + are implicitly treated as having their value "always enabled". Thus, + in the example above, the day-of-the-month mask is not present, and + so the validity period for the instance implicitly includes a day- + of-the-month mask that selects all days of the month. If we apply + this "missing property" rule to its fullest, we see that there is a + second way to indicate that a policy rule is always enabled: have it + point to an instance of PolicyTimePeriodCondition whose only + properties are its naming properties. + + The property LocalOrUtcTime indicates whether the times represented + in the other five time-related properties of an instance of + PolicyTimePeriodCondition are to be interpreted as local times for + the location where a policy rule is being applied, or as UTC times. + + The class definition is as follows. + + NAME PolicyTimePeriodCondition + DESCRIPTION A class that provides the capability of enabling / + disabling a policy rule according to a + pre-determined schedule. + DERIVED FROM PolicyCondition + ABSTRACT FALSE + PROPERTIES TimePeriod + MonthOfYearMask + DayOfMonthMask + DayOfWeekMask + TimeOfDayMask + LocalOrUtcTime + + + + + + +Moore, et al. Standards Track [Page 37] + +RFC 3060 Policy Core Information Model February 2001 + + +6.5.1. The Property "TimePeriod" + + This property identifies an overall range of calendar dates and times + over which a policy rule is valid. It reuses the format for an + explicit time period defined in RFC 2445 (reference [10]): a string + representing a starting date and time, in which the character 'T' + indicates the beginning of the time portion, followed by the solidus + character '/', followed by a similar string representing an end date + and time. The first date indicates the beginning of the range, while + the second date indicates the end. Thus, the second date and time + must be later than the first. Date/times are expressed as substrings + of the form "yyyymmddThhmmss". For example: + + 20000101T080000/20000131T120000 + + January 1, 2000, 0800 through January 31, 2000, noon + + There are also two special cases in which one of the date/time + strings is replaced with a special string defined in RFC 2445. + + o If the first date/time is replaced with the string "THISANDPRIOR", + then the property indicates that a policy rule is valid [from now] + until the date/time that appears after the '/'. + + o If the second date/time is replaced with the string + "THISANDFUTURE", then the property indicates that a policy rule + becomes valid on the date/time that appears before the '/', and + remains valid from that point on. + + Note that RFC 2445 does not use these two strings in connection with + explicit time periods. Thus the PCIM is combining two elements from + RFC 2445 that are not combined in the RFC itself. + + The property definition is as follows: + + NAME TimePeriod + DESCRIPTION The range of calendar dates on which a policy + rule is valid. + SYNTAX string + FORMAT yyyymmddThhmmss/yyyymmddThhmmss, where the first + date/time may be replaced with the string + "THISANDPRIOR" or the second date/time may be + replaced with the string "THISANDFUTURE" + + + + + + + + +Moore, et al. Standards Track [Page 38] + +RFC 3060 Policy Core Information Model February 2001 + + +6.5.2. The Property "MonthOfYearMask" + + The purpose of this property is to refine the definition of the valid + time period that is defined by the TimePeriod property, by explicitly + specifying the months when the policy is valid. These properties + work together, with the TimePeriod used to specify the overall time + period during which the policy might be valid, and the + MonthOfYearMask used to pick out the specific months within that time + period when the policy is valid. + + This property is formatted as an octet string of size 2, consisting + of 12 bits identifying the 12 months of the year, beginning with + January and ending with December, followed by 4 bits that are always + set to '0'. For each month, the value '1' indicates that the policy + is valid for that month, and the value '0' indicates that it is not + valid. The value X'08 30', for example, indicates that a policy rule + is valid only in the months May, November, and December. + + See section 5.4 for details of how CIM represents a single-valued + octet string property such as this one. (Basically, CIM prepends a + 4-octet length to the octet string.) + + If this property is omitted, then the policy rule is treated as valid + for all twelve months. The property definition is as follows: + + NAME MonthOfYearMask + DESCRIPTION A mask identifying the months of the year in + which a policy rule is valid. + SYNTAX octet string + FORMAT X'hh h0' + +6.5.3. The Property "DayOfMonthMask" + + The purpose of this property is to refine the definition of the valid + time period that is defined by the TimePeriod property, by explicitly + specifying the days of the month when the policy is valid. These + properties work together, with the TimePeriod used to specify the + overall time period during which the policy might be valid, and the + DayOfMonthMask used to pick out the specific days of the month within + that time period when the policy is valid. + + This property is formatted as an octet string of size 8, consisting + of 31 bits identifying the days of the month counting from the + beginning, followed by 31 more bits identifying the days of the month + counting from the end, followed by 2 bits that are always set to '0'. + For each day, the value '1' indicates that the policy is valid for + that day, and the value '0' indicates that it is not valid. + + + + +Moore, et al. Standards Track [Page 39] + +RFC 3060 Policy Core Information Model February 2001 + + + The value X'80 00 00 01 00 00 00 00', for example, indicates that a + policy rule is valid on the first and last days of the month. + + For months with fewer than 31 days, the digits corresponding to days + that the months do not have (counting in both directions) are + ignored. + + The encoding of the 62 significant bits in the octet string matches + that used for the schedDay object in the DISMAN-SCHEDULE-MIB. See + reference [8] for more details on this object. + + See section 5.4 for details of how CIM represents a single-valued + octet string property such as this one. (Basically, CIM prepends a + 4-octet length to the octet string.) + + The property definition is as follows: + + NAME DayOfMonthMask + DESCRIPTION A mask identifying the days of the month on + which a policy rule is valid. + SYNTAX octet string + FORMAT X'hh hh hh hh hh hh hh hh' + +6.5.4. The Property "DayOfWeekMask" + + The purpose of this property is to refine the definition of the valid + time period that is defined by the TimePeriod property by explicitly + specifying the days of the week when the policy is valid. These + properties work together, with the TimePeriod used to specify the + overall time period when the policy might be valid, and the + DayOfWeekMask used to pick out the specific days of the week in that + time period when the policy is valid. + + This property is formatted as an octet string of size 1, consisting + of 7 bits identifying the 7 days of the week, beginning with Sunday + and ending with Saturday, followed by 1 bit that is always set to + '0'. For each day of the week, the value '1' indicates that the + policy is valid for that day, and the value '0' indicates that it is + not valid. + + The value X'7C', for example, indicates that a policy rule is valid + Monday through Friday. + + See section 5.4 for details of how CIM represents a single-valued + octet string property such as this one. (Basically, CIM prepends a + 4-octet length to the octet string.) + + + + + +Moore, et al. Standards Track [Page 40] + +RFC 3060 Policy Core Information Model February 2001 + + + The property definition is as follows: + + NAME DayOfWeekMask + DESCRIPTION A mask identifying the days of the week on which + a policy rule is valid. + SYNTAX octet string + FORMAT B'bbbb bbb0' + +6.5.5. The Property "TimeOfDayMask" + + The purpose of this property is to refine the definition of the valid + time period that is defined by the TimePeriod property by explicitly + specifying a range of times in a day the policy is valid for. These + properties work together, with the TimePeriod used to specify the + overall time period that the policy is valid for, and the + TimeOfDayMask used to pick out which range of time periods in a given + day of that time period the policy is valid for. + + This property is formatted in the style of RFC 2445 [10]: a time + string beginning with the character 'T', followed by the solidus + character '/', followed by a second time string. The first time + indicates the beginning of the range, while the second time indicates + the end. Times are expressed as substrings of the form "Thhmmss". + + The second substring always identifies a later time than the first + substring. To allow for ranges that span midnight, however, the + value of the second string may be smaller than the value of the first + substring. Thus, "T080000/T210000" identifies the range from 0800 + until 2100, while "T210000/T080000" identifies the range from 2100 + until 0800 of the following day. + + When a range spans midnight, it by definition includes parts of two + successive days. When one of these days is also selected by either + the MonthOfYearMask, DayOfMonthMask, and/or DayOfWeekMask, but the + other day is not, then the policy is active only during the portion + of the range that falls on the selected day. For example, if the + range extends from 2100 until 0800, and the day of week mask selects + Monday and Tuesday, then the policy is active during the following + three intervals: + + From midnight Sunday until 0800 Monday; + From 2100 Monday until 0800 Tuesday; + From 2100 Tuesday until 23:59:59 Tuesday. + + + + + + + + +Moore, et al. Standards Track [Page 41] + +RFC 3060 Policy Core Information Model February 2001 + + + The property definition is as follows: + + NAME TimeOfDayMask + DESCRIPTION The range of times at which a policy rule is + valid. If the second time is earlier than the + first, then the interval spans midnight. + SYNTAX string + FORMAT Thhmmss/Thhmmss + +6.5.6. The Property "LocalOrUtcTime" + + This property indicates whether the times represented in the + TimePeriod property and in the various Mask properties represent + local times or UTC times. There is no provision for mixing of local + times and UTC times: the value of this property applies to all of + the other time-related properties. + + The property definition is as follows: + + NAME LocalOrUtcTime + DESCRIPTION An indication of whether the other times in this + instance represent local times or UTC times. + SYNTAX uint16 + VALUES localTime(1), utcTime(2) + DEFAULT VALUE utcTime(2) + +6.6. The Class "VendorPolicyCondition" + + The purpose of this class is to provide a general extension mechanism + for representing policy conditions that have not been modeled with + specific properties. Instead, the two properties Constraint and + ConstraintEncoding are used to define the content and format of the + condition, as explained below. + + As its name suggests, this class is intended for vendor-specific + extensions to the Policy Core Information Model. Standardized + extensions are not expected to use this class. + + The class definition is as follows: + + NAME VendorPolicyCondition + DESCRIPTION A class that defines a registered means to + describe a policy condition. + DERIVED FROM PolicyCondition + ABSTRACT FALSE + PROPERTIES Constraint[ ] + ConstraintEncoding + + + + +Moore, et al. Standards Track [Page 42] + +RFC 3060 Policy Core Information Model February 2001 + + +6.6.1. The Multi-valued Property "Constraint" + + This property provides a general extension mechanism for representing + policy conditions that have not been modeled with specific + properties. The format of the octet strings in the array is left + unspecified in this definition. It is determined by the OID value + stored in the property ConstraintEncoding. Since ConstraintEncoding + is single-valued, all the values of Constraint share the same format + and semantics. + + See Section 5.4 for a description of how CIM encodes an array of + octet strings like this one. + + A policy decision point can readily determine whether it supports the + values stored in an instance of Constraint by checking the OID value + from ConstraintEncoding against the set of OIDs it recognizes. The + action for the policy decision point to take in case it does not + recognize the format of this data could itself be modeled as a policy + rule, governing the behavior of the policy decision point. + + The property is defined as follows: + + NAME Constraint + DESCRIPTION Extension mechanism for representing constraints + that have not been modeled as specific + properties. The format of the values is + identified by the OID stored in the property + ConstraintEncoding. + SYNTAX octet string + +6.6.2. The Property "ConstraintEncoding" + + This property identifies the encoding and semantics of the Constraint + property values in this instance. The value of this property is a + single string, representing a single OID. + + The property is defined as follows: + + NAME ConstraintEncoding + DESCRIPTION An OID encoded as a string, identifying the format + and semantics for this instance's Constraint + property. The value is a dotted sequence of + decimal digits (for example, "1.2.100.200") + representing the arcs of the OID. The characters + in the string are the UCS-2 characters + corresponding to the US ASCII encodings of the + numeric characters and the period. + SYNTAX string + + + +Moore, et al. Standards Track [Page 43] + +RFC 3060 Policy Core Information Model February 2001 + + +6.7. The Abstract Class "PolicyAction" + + The purpose of a policy action is to execute one or more operations + that will affect network traffic and/or systems, devices, etc., in + order to achieve a desired state. This (new) state provides one or + more (new) behaviors. A policy action ordinarily changes the + configuration of one or more elements. + + A PolicyRule contains one or more policy actions. A policy + administrator can assign an order to the actions associated with a + PolicyRule, complete with an indication of whether the indicated + order is mandatory, recommended, or of no significance. Ordering of + the actions associated with a PolicyRule is accomplished via a + property in the PolicyActionInPolicyRule aggregation. + + The actions associated with a PolicyRule are executed if and only if + the overall condition(s) of the PolicyRule evaluates to TRUE. + + The class definition of PolicyAction is as follows: + + NAME PolicyAction + DESCRIPTION A class representing a rule-specific or reusable + policy action to be performed if the condition for + a policy rule evaluates to TRUE. + DERIVED FROM Policy + ABSTRACT TRUE + PROPERTIES NONE + + No properties are defined for this class since it inherits all its + properties from Policy. The class exists as an abstract superclass + for domain-specific policy actions, defined in subclasses. In an + implementation, various key/identification properties MUST be defined + for the class or its instantiable subclasses. The keys for a native + CIM implementation are defined in Appendix A, Section 13.3. Keys for + an LDAP implementation will be defined in the LDAP mapping of this + information model [11]. + + When identifying and using the PolicyAction class, it is necessary to + remember that an action can be rule-specific or reusable. This was + discussed above in Section 5.1. The distinction between the two + types of policy actions lies in the associations in which an instance + can participate, and in how the different instances are named. + Conceptually, a reusable policy action resides in a policy + repository, and is named within the scope of that repository. On the + other hand, a rule-specific policy action is named within the scope + of the single policy rule to which it is related. + + + + + +Moore, et al. Standards Track [Page 44] + +RFC 3060 Policy Core Information Model February 2001 + + + The distinction between rule-specific and reusable PolicyActions + affects the CIM naming, defined in Appendix A, and the LDAP mapping + [11]. + +6.8. The Class "VendorPolicyAction" + + The purpose of this class is to provide a general extension mechanism + for representing policy actions that have not been modeled with + specific properties. Instead, the two properties ActionData and + ActionEncoding are used to define the content and format of the + action, as explained below. + + As its name suggests, this class is intended for vendor-specific + extensions to the Policy Core Information Model. Standardized + extensions are not expected to use this class. + + The class definition is as follows: + + NAME VendorPolicyAction + DESCRIPTION A class that defines a registered means to + describe a policy action. + DERIVED FROM PolicyAction + ABSTRACT FALSE + PROPERTIES ActionData[ ] + ActionEncoding + +6.8.1. The Multi-valued Property "ActionData" + + This property provides a general extension mechanism for representing + policy actions that have not been modeled with specific properties. + The format of the octet strings in the array is left unspecified in + this definition. It is determined by the OID value stored in the + property ActionEncoding. Since ActionEncoding is single-valued, all + the values of ActionData share the same format and semantics. See + Section 5.4 for a discussion of how CIM encodes an array of octet + strings like this one. + + A policy decision point can readily determine whether it supports the + values stored in an instance of ActionData by checking the OID value + from ActionEncoding against the set of OIDs it recognizes. The + action for the policy decision point to take in case it does not + recognize the format of this data could itself be modeled as a policy + rule, governing the behavior of the policy decision point. + + + + + + + + +Moore, et al. Standards Track [Page 45] + +RFC 3060 Policy Core Information Model February 2001 + + + The property is defined as follows: + + NAME ActionData + DESCRIPTION Extension mechanism for representing actions that + have not been modeled as specific properties. The + format of the values is identified by the OID + stored in the property ActionEncoding. + SYNTAX octet string + +6.8.2. The Property "ActionEncoding" + + This property identifies the encoding and semantics of the ActionData + property values in this instance. The value of this property is a + single string, representing a single OID. + + The property is defined as follows: + + NAME ActionEncoding + DESCRIPTION An OID encoded as a string, identifying the format + and semantics for this instance's ActionData + property. The value is a dotted sequence of + decimal digits (for example, "1.2.100.200") + representing the arcs of the OID. The characters + in the string are the UCS-2 characters + corresponding to the US ASCII encodings of the + numeric characters and the period. + SYNTAX string + +6.9. The Class "PolicyRepository" + + The class definition of PolicyRepository is as follows: + + NAME PolicyRepository + DESCRIPTION A class representing an administratively defined + container for reusable policy-related + information. This class does not introduce any + additional properties beyond those in its + superclass AdminDomain. It does, however, + participate in a number of unique associations. + DERIVED FROM AdminDomain + ABSTRACT FALSE + +7. Association and Aggregation Definitions + + The first two subsections of this section introduce associations and + aggregations as they are used in CIM. The remaining subsections + present the class definitions for the associations and aggregations + that are part of the Policy Core Information Model. + + + +Moore, et al. Standards Track [Page 46] + +RFC 3060 Policy Core Information Model February 2001 + + +7.1. Associations + + An association is a CIM construct representing a relationship between + two (or theoretically more) objects. It is modeled as a class + containing typically two object references. Associations can be + defined between classes without affecting any of the related classes. + That is, addition of an association does not affect the interface of + the related classes. + +7.2. Aggregations + + An aggregation is a strong form of an association, which usually + represents a "whole-part" or a "collection" relationship. For + example, CIM uses an aggregation to represent the containment + relationship between a system and the components that make up the + system. Aggregation as a "whole-part" relationship often implies, + but does not require, that the aggregated objects have mutual + dependencies. + +7.3. The Abstract Aggregation "PolicyComponent + + This abstract aggregation defines two object references that will be + overridden in each of five subclasses, to become references to the + concrete policy classes PolicyGroup, PolicyRule, PolicyCondition, + PolicyAction, and PolicyTimePeriodCondition. The value of the + abstract superclass is to convey that all five subclasses have the + same "whole- part" semantics, and for ease of query to locate all + "components" of a PolicyGroup or PolicyRule. + + The class definition for the aggregation is as follows: + + NAME PolicyComponent + DESCRIPTION A generic aggregation used to establish 'part of' + relationships between the subclasses of + Policy. For example, the + PolicyConditionInPolicyRule aggregation defines + that PolicyConditions are part of a PolicyRule. + ABSTRACT TRUE + PROPERTIES GroupComponent[ref Policy[0..n]] + PartComponent[ref Policy[0..n]] + +7.4. The Aggregation "PolicyGroupInPolicyGroup" + + The PolicyGroupInPolicyGroup aggregation enables policy groups to be + nested. This is critical for scalability and manageability, as it + enables complex policies to be constructed from multiple simpler + + + + + +Moore, et al. Standards Track [Page 47] + +RFC 3060 Policy Core Information Model February 2001 + + + policies for administrative convenience. For example, a policy group + representing policies for the US might have nested within it policy + groups for the Eastern and Western US. + + A PolicyGroup may aggregate other PolicyGroups via this aggregation, + or it may aggregate PolicyRules via the PolicyRuleInPolicyGroup + aggregation. Note that it is assumed that this aggregation is used + to form directed acyclic graphs and NOT ring structures.The class + definition for the aggregation is as follows: + + NAME PolicyGroupInPolicyGroup + DESCRIPTION A class representing the aggregation of + PolicyGroups by a higher-level PolicyGroup. + DERIVED FROM PolicyComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyGroup[0..n]] + PartComponent[ref PolicyGroup[0..n]] + +7.4.1. The Reference "GroupComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyGroup that contains one or more + other PolicyGroups. Note that for any single instance of the + aggregation class PolicyGroupInPolicyGroup, this property (like all + Reference properties) is single-valued. The [0..n] cardinality + indicates that there may be 0, 1, or more than one PolicyGroups that + contain any given PolicyGroup. + +7.4.2. The Reference "PartComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyGroup contained by one or more + other PolicyGroups. Note that for any single instance of the + aggregation class PolicyGroupInPolicyGroup, this property (like all + Reference properties) is single-valued. The [0..n] cardinality + indicates that a given PolicyGroup may contain 0, 1, or more than one + other PolicyGroups. + +7.5. The Aggregation "PolicyRuleInPolicyGroup" + + A policy group may aggregate one or more policy rules, via the + PolicyRuleInPolicyGroup aggregation. Grouping of policy rules into a + policy group is again for administrative convenience; a policy rule + may also be used by itself, without belonging to a policy group. + + A PolicyGroup may aggregate PolicyRules via this aggregation, or it + may aggregate other PolicyGroups via the PolicyGroupInPolicyGroup + aggregation. + + + +Moore, et al. Standards Track [Page 48] + +RFC 3060 Policy Core Information Model February 2001 + + + The class definition for the aggregation is as follows: + + NAME PolicyRuleInPolicyGroup + DESCRIPTION A class representing the aggregation of + PolicyRules by a PolicyGroup. + DERIVED FROM PolicyComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyGroup[0..n]] + PartComponent[ref PolicyRule[0..n]] + +7.5.1. The Reference "GroupComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyGroup that contains one or more + PolicyRules. Note that for any single instance of the aggregation + class PolicyRuleInPolicyGroup, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + there may be 0, 1, or more than one PolicyGroups that contain any + given PolicyRule. + +7.5.2. The Reference "PartComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyRule contained by one or more + PolicyGroups. Note that for any single instance of the aggregation + class PolicyRuleInPolicyGroup, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + a given PolicyGroup may contain 0, 1, or more than one PolicyRules. + +7.6. The Aggregation "PolicyConditionInPolicyRule" + + A policy rule aggregates zero or more instances of the + PolicyCondition class, via the PolicyConditionInPolicyRule + association. A policy rule that aggregates zero policy conditions + must indicate in its class definition what "triggers" the performance + of its actions. In short, it must describe its implicit + PolicyConditions, since none are explicitly associated. For example, + there might be a subclass of PolicyRule named "HttpPolicyRule", where + the class definition assumes that the condition, "If HTTP traffic," + is true before the rule's actions would be performed. There is no + need to formalize and instantiate this condition, since it is obvious + in the semantics of the PolicyRule. + + The conditions aggregated by a policy rule are grouped into two + levels of lists: either an ORed set of ANDed sets of conditions (DNF, + the default) or an ANDed set of ORed sets of conditions (CNF). + Individual conditions in these lists may be negated. The property + ConditionListType (in PolicyRule) specifies which of these two + + + +Moore, et al. Standards Track [Page 49] + +RFC 3060 Policy Core Information Model February 2001 + + + grouping schemes applies to a particular PolicyRule. The conditions + are used to determine whether to perform the actions associated with + the PolicyRule. + + One or more policy time periods may be among the conditions + associated with a policy rule via the PolicyConditionInPolicyRule + association. In this case, the time periods are simply additional + conditions to be evaluated along with any other conditions specified + for the rule. + + The class definition for the aggregation is as follows: + + NAME PolicyConditionInPolicyRule + DESCRIPTION A class representing the aggregation of + PolicyConditions by a PolicyRule. + DERIVED FROM PolicyComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyRule[0..n]] + PartComponent[ref PolicyCondition[0..n]] + GroupNumber + ConditionNegated + +7.6.1. The Reference "GroupComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyRule that contains one or more + PolicyConditions. Note that for any single instance of the + aggregation class PolicyConditionInPolicyRule, this property (like + all Reference properties) is single-valued. The [0..n] cardinality + indicates that there may be 0, 1, or more than one PolicyRules that + contain any given PolicyCondition. + +7.6.2. The Reference "PartComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyCondition contained by one or + more PolicyRules. Note that for any single instance of the + aggregation class PolicyConditionInPolicyRule, this property (like + all Reference properties) is single-valued. The [0..n] cardinality + indicates that a given PolicyRule may contain 0, 1, or more than one + PolicyConditions. + +7.6.3. The Property "GroupNumber" + + This property contains an integer identifying the group to which the + condition referenced by the PartComponent property is assigned in + forming the overall conditional expression for the policy rule + identified by the GroupComponent reference. + + + +Moore, et al. Standards Track [Page 50] + +RFC 3060 Policy Core Information Model February 2001 + + + The property is defined as follows: + + NAME GroupNumber + DESCRIPTION Unsigned integer indicating the group to which + the condition identified by the PartComponent + property is to be assigned. + SYNTAX uint16 + DEFAULT 0 + +7.6.4. The Property "ConditionNegated" + + This property is a boolean, indicating whether the condition + referenced by the PartComponent property is negated in forming the + overall conditional expression for the policy rule identified by the + GroupComponent reference. + + The property is defined as follows: + + NAME ConditionNegated + DESCRIPTION Indication of whether the condition identified by + the PartComponent property is negated. (TRUE + indicates that the condition is negated, FALSE + indicates that it is not negated.) + SYNTAX boolean + DEFAULT FALSE + +7.7. The Aggregation "PolicyRuleValidityPeriod" + + A different relationship between a policy rule and a policy time + period (than PolicyConditionInPolicyRule) is represented by the + PolicyRuleValidityPeriod aggregation. The latter describes scheduled + activation and deactivation of the policy rule. + + If a policy rule is associated with multiple policy time periods via + this association, then the rule is active if at least one of the time + periods indicates that it is active. (In other words, the time + periods are ORed to determine whether the rule is active.) A policy + time period may be aggregated by multiple policy rules. A rule that + does not point to a policy time period via this aggregation is, from + the point of view of scheduling, always active. It may, however, be + inactive for other reasons. + + Time periods are a general concept that can be used in other + applications. However, they are mentioned explicitly here in this + specification since they are frequently used in policy applications. + + + + + + +Moore, et al. Standards Track [Page 51] + +RFC 3060 Policy Core Information Model February 2001 + + + The class definition for the aggregation is as follows: + + NAME PolicyRuleValidityPeriod + DESCRIPTION A class representing the aggregation of + PolicyTimePeriodConditions by a PolicyRule. + DERIVED FROM PolicyComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyRule[0..n]] + PartComponent[ref PolicyTimePeriodCondition[0..n]] + +7.7.1. The Reference "GroupComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyRule that contains one or more + PolicyTimePeriodConditions. Note that for any single instance of the + aggregation class PolicyRuleValidityPeriod, this property (like all + Reference properties) is single-valued. The [0..n] cardinality + indicates that there may be 0, 1, or more than one PolicyRules that + contain any given PolicyTimePeriodCondition. + +7.7.2. The Reference "PartComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyTimePeriodCondition contained + by one or more PolicyRules. Note that for any single instance of the + aggregation class PolicyRuleValidityPeriod, this property (like all + Reference properties) is single-valued. The [0..n] cardinality + indicates that a given PolicyRule may contain 0, 1, or more than one + PolicyTimePeriodConditions. + +7.8. The Aggregation "PolicyActionInPolicyRule" + + A policy rule may aggregate zero or more policy actions. A policy + rule that aggregates zero policy actions must indicate in its class + definition what actions are taken when the rule's conditions evaluate + to TRUE. In short, it must describe its implicit PolicyActions, + since none are explicitly associated. For example, there might be a + subclass of PolicyRule representing a Diffserv absolute dropper, + where the subclass itself indicates the action to be taken. There is + no need to formalize and instantiate this action, since it is obvious + in the semantics of the PolicyRule. + + The actions associated with a PolicyRule may be given a required + order, a recommended order, or no order at all. For actions + represented as separate objects, the PolicyActionInPolicyRule + aggregation can be used to express an order. + + + + + +Moore, et al. Standards Track [Page 52] + +RFC 3060 Policy Core Information Model February 2001 + + + This aggregation does not indicate whether a specified action order + is required, recommended, or of no significance; the property + SequencedActions in the aggregating instance of PolicyRule provides + this indication. + + The class definition for the aggregation is as follows: + + NAME PolicyActionInPolicyRule + DESCRIPTION A class representing the aggregation of + PolicyActions by a PolicyCondition. + DERIVED FROM PolicyComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyRule[0..n]] + PartComponent[ref PolicyAction[0..n]] + ActionOrder + +7.8.1. The Reference "GroupComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyRule that contains one or more + PolicyActions. Note that for any single instance of the aggregation + class PolicyActionInPolicyRule, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + there may be 0, 1, or more than one PolicyRules that contain any + given PolicyAction. + +7.8.2. The Reference "PartComponent" + + This property is inherited from PolicyComponent, and overridden to + become an object reference to a PolicyAction contained by one or more + PolicyRules. Note that for any single instance of the aggregation + class PolicyActionInPolicyRule, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + a given PolicyRule may contain 0, 1, or more than one PolicyActions. + +7.8.3. The Property "ActionOrder" + + This property provides an unsigned integer 'n' that indicates the + relative position of an action in the sequence of actions associated + with a policy rule. When 'n' is a positive integer, it indicates a + place in the sequence of actions to be performed, with smaller + integers indicating earlier positions in the sequence. The special + value '0' indicates "don't care". If two or more actions have the + same non-zero sequence number, they may be performed in any order, + but they must all be performed at the appropriate place in the + overall action sequence. + + + + + +Moore, et al. Standards Track [Page 53] + +RFC 3060 Policy Core Information Model February 2001 + + + A series of examples will make ordering of actions clearer: + + o If all actions have the same sequence number, regardless of + whether it is '0' or non-zero, any order is acceptable. + + o The values + + 1:ACTION A + 2:ACTION B + 1:ACTION C + 3:ACTION D + + indicate two acceptable orders: A,C,B,D or C,A,B,D, since A and C + can be performed in either order, but only at the '1' position. + + o The values + + 0:ACTION A + 2:ACTION B + 3:ACTION C + 3:ACTION D + + require that B,C, and D occur either as B,C,D or as B,D,C. Action + A may appear at any point relative to B,C, and D. Thus the + complete set of acceptable orders is: A,B,C,D; B,A,C,D; B,C,A,D; + B,C,D,A; A,B,D,C; B,A,D,C; B,D,A,C; B,D,C,A. + + Note that the non-zero sequence numbers need not start with '1', + and they need not be consecutive. All that matters is their + relative magnitude. + + The property is defined as follows: + + NAME ActionOrder + DESCRIPTION Unsigned integer indicating the relative position + of an action in the sequence of actions aggregated + by a policy rule. + SYNTAX uint16 + +7.9. The Abstract Association "PolicyInSystem" + + This abstract association inherits two object references from a + higher- level CIM association class, Dependency. It overrides these + object references to make them references to instances of the classes + System and Policy. Subclasses of PolicyInSystem then override these + object references again, to make them references to concrete policy + classes. + + + + +Moore, et al. Standards Track [Page 54] + +RFC 3060 Policy Core Information Model February 2001 + + + The value of the abstract superclass is to convey that all subclasses + have the same "dependency" semantics, and for ease of query to locate + all policy "dependencies" on a System. These dependencies are + related to scoping or hosting of the Policy. + + The class definition for the association is as follows: + + NAME PolicyInSystem + DESCRIPTION A generic association used to establish + dependency relationships between Policies and the + Systems that host them. + DERIVED FROM Dependency + ABSTRACT TRUE + PROPERTIES Antecedent[ref System[0..1]] + Dependent[ref Policy[0..n]] + +7.10. The Weak Association "PolicyGroupInSystem" + + This association links a PolicyGroup to the System in whose scope the + PolicyGroup is defined. + + The class definition for the association is as follows: + + NAME PolicyGroupInSystem + DESCRIPTION A class representing the fact that a PolicyGroup + is defined within the scope of a System. + DERIVED FROM PolicyInSystem + ABSTRACT FALSE + PROPERTIES Antecedent[ref System[1..1]] + Dependent[ref PolicyGroup[weak]] + +7.10.1. The Reference "Antecedent" + + This property is inherited from PolicyInSystem, and overridden to + restrict its cardinality to [1..1]. It serves as an object reference + to a System that provides a scope for one or more PolicyGroups. + Since this is a weak association, the cardinality for this object + reference is always 1, that is, a PolicyGroup is always defined + within the scope of exactly one System. + +7.10.2. The Reference "Dependent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyGroup defined within the scope + of a System. Note that for any single instance of the association + class PolicyGroupInSystem, this property (like all Reference + + + + + +Moore, et al. Standards Track [Page 55] + +RFC 3060 Policy Core Information Model February 2001 + + + properties) is single-valued. The [0..n] cardinality indicates that + a given System may have 0, 1, or more than one PolicyGroups defined + within its scope. + +7.11. The Weak Association "PolicyRuleInSystem" + + Regardless of whether it belongs to a PolicyGroup (or to multiple + PolicyGroups), a PolicyRule is itself defined within the scope of a + System. This association links a PolicyRule to the System in whose + scope the PolicyRule is defined. + + The class definition for the association is as follows: + + NAME PolicyRuleInSystem + DESCRIPTION A class representing the fact that a PolicyRule + is defined within the scope of a System. + DERIVED FROM PolicyInSystem + ABSTRACT FALSE + PROPERTIES Antecedent[ref System[1..1]] + Dependent[ref PolicyRule[weak]] + +7.11.1. The Reference "Antecedent" + + This property is inherited from PolicyInSystem, and overridden to + restrict its cardinality to [1..1]. It serves as an object reference + to a System that provides a scope for one or more PolicyRules. Since + this is a weak association, the cardinality for this object reference + is always 1, that is, a PolicyRule is always defined within the scope + of exactly one System. + +7.11.2. The Reference "Dependent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyRule defined within the scope + of a System. Note that for any single instance of the association + class PolicyRuleInSystem, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + a given System may have 0, 1, or more than one PolicyRules defined + within its scope. + +7.12. The Association "PolicyConditionInPolicyRepository" + + A reusable policy condition is always related to a single + PolicyRepository, via the PolicyConditionInPolicyRepository + association. This is not true for all PolicyConditions, however. An + instance of PolicyCondition that represents a rule-specific condition + is not related to any policy repository via this association. + + + + +Moore, et al. Standards Track [Page 56] + +RFC 3060 Policy Core Information Model February 2001 + + + The class definition for the association is as follows: + + NAME PolicyConditionInPolicyRepository + DESCRIPTION A class representing the inclusion of a reusable + PolicyCondition in a PolicyRepository. + DERIVED FROM PolicyInSystem + ABSTRACT FALSE + PROPERTIES Antecedent[ref PolicyRepository[0..1]] + Dependent[ref PolicyCondition[0..n]] + +7.12.1. The Reference "Antecedent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyRepository containing one or + more PolicyConditions. A reusable PolicyCondition is always related + to exactly one PolicyRepository via the + PolicyConditionInPolicyRepository association. The [0..1] + cardinality for this property covers the two types of + PolicyConditions: 0 for a rule-specific PolicyCondition, 1 for a + reusable one. + +7.12.2. The Reference "Dependent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyCondition included in a + PolicyRepository. Note that for any single instance of the + association class PolicyConditionInPolicyRepository, this property + (like all Reference properties) is single-valued. The [0..n] + cardinality indicates that a given PolicyRepository may contain 0, 1, + or more than one PolicyConditions. + +7.13. The Association "PolicyActionInPolicyRepository" + + A reusable policy action is always related to a single + PolicyRepository, via the PolicyActionInPolicyRepository association. + This is not true for all PolicyActions, however. An instance of + PolicyAction that represents a rule-specific action is not related to + any policy repository via this association. + + The class definition for the association is as follows: + + NAME PolicyActionInPolicyRepository + DESCRIPTION A class representing the inclusion of a reusable + PolicyAction in a PolicyRepository. + DERIVED FROM PolicyInSystem + ABSTRACT FALSE + PROPERTIES Antecedent[ref PolicyRepository[0..1]] + Dependent[ref PolicyAction[0..n]] + + + +Moore, et al. Standards Track [Page 57] + +RFC 3060 Policy Core Information Model February 2001 + + +7.13.1. The Reference "Antecedent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyRepository containing one or + more PolicyActions. A reusable PolicyAction is always related to + exactly one PolicyRepository via the PolicyActionInPolicyRepository + association. The [0..1] cardinality for this property covers the two + types of PolicyActions: 0 for a rule-specific PolicyAction, 1 for a + reusable one. + +7.13.2. The Reference "Dependent" + + This property is inherited from PolicyInSystem, and overridden to + become an object reference to a PolicyAction included in a + PolicyRepository. Note that for any single instance of the + association class PolicyActionInPolicyRepository, this property (like + all Reference properties) is single-valued. The [0..n] cardinality + indicates that a given PolicyRepository may contain 0, 1, or more + than one PolicyActions. + +7.14. The Aggregation "PolicyRepositoryInPolicyRepository" + + The PolicyRepositoryInPolicyRepository aggregation enables policy + repositories to be nested. This derives from the higher level CIM + association, CIM_SystemComponent, describing that Systems contain + other ManagedSystemElements. This superclass could not be used for + the other Policy aggregations, since Policies are not + ManagedSystemElements, but ManagedElements. Note that it is assumed + that this aggregation is used to form directed acyclic graphs and NOT + ring structures. + + The class definition for the aggregation is as follows: + + NAME PolicyRepositoryInPolicyRepository + DESCRIPTION A class representing the aggregation of + PolicyRepositories by a higher-level + PolicyRepository. + DERIVED FROM SystemComponent + ABSTRACT FALSE + PROPERTIES GroupComponent[ref PolicyRepository[0..n]] + PartComponent[ref PolicyRepository[0..n]] +7.14.1. The Reference "GroupComponent" + + This property is inherited from the CIM class SystemComponent, and + overridden to become an object reference to a PolicyRepository that + contains one or more other PolicyRepositories. Note that for any + single instance of the aggregation class + PolicyRepositoryInPolicyRepository, this property (like all Reference + + + +Moore, et al. Standards Track [Page 58] + +RFC 3060 Policy Core Information Model February 2001 + + + properties) is single-valued. The [0..n] cardinality indicates that + there may be 0, 1, or more than one PolicyRepositories that contain + any given PolicyRepository. + +7.14.2. The Reference "PartComponent" + + This property is inherited from the CIM class SystemComponent, and + overridden to become an object reference to a PolicyRepository + contained by one or more other PolicyRepositories. Note that for any + single instance of the aggregation class + PolicyRepositoryInPolicyRepository, this property (like all Reference + properties) is single-valued. The [0..n] cardinality indicates that + a given PolicyRepository may contain 0, 1, or more than one other + PolicyRepositories. + +8. Intellectual Property + + The IETF takes no position regarding the validity or scope of any + intellectual property or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; neither does it represent that it + has made any effort to identify any such rights. Information on the + IETF's procedures with respect to rights in standards-track and + standards-related documentation can be found in BCP-11. + + Copies of claims of rights made available for publication and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF Secretariat. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights which may cover technology that may be required to practice + this standard. Please address the information to the IETF Executive + Director. + +9. Acknowledgements + + The Policy Core Information Model in this document is closely based + on the work of the DMTF's Service Level Agreements working group, so + thanks are due to the members of that working group. Several of the + policy classes in this model first appeared in early drafts on IPSec + policy and QoS policy. The authors of these drafts were Partha + Bhattacharya, Rob Adams, William Dixon, Roy Pereira, Raju Rajan, + Jean-Christophe Martin, Sanjay Kamat, Michael See, Rajiv Chaudhury, + Dinesh Verma, George Powers, and Raj Yavatkar. Some other elements + + + +Moore, et al. Standards Track [Page 59] + +RFC 3060 Policy Core Information Model February 2001 + + + of the model originated in work done by Yoram Snir, Yoram Ramberg, + and Ron Cohen. In addition, we would like to thank Harald Alvestrand + for conducting a thorough review of this document and providing many + helpful suggestions, and Luis Sanchez and Russ Mundy for their help + with the document's Security Considerations. + +10. Security Considerations + + The Policy Core Information Model (PCIM) presented in this document + provides an object-oriented model for describing policy information. + It provides a basic framework for describing the structure of policy + information, in a form independent of any specific repository or + access protocol, for use by an operational system. PCIM is not + intended to represent any particular system design or implementation, + nor does it define a protocol, and as such it does not have any + specific security requirements. + + However, it should also be noted that certain derivative documents, + which use PCIM as a base, will need to convey more specific security + considerations. In order to communicate the nature of what will be + expected in these follow-on derivative documents, it is necessary to + review the reasons that PCIM, as defined in this document, is neither + implementable, nor representative of any real-world system, as well + as the nature of the expected follow-on extensions and mappings. + + There are three independent reasons that PCIM, as defined here, is + neither implementable nor representative of any real-world system: + + 1. Its classes are independent of any specific repository that + uses any specific access protocol. Therefore, its classes are + designed not to be implemented directly. PCIM should instead + be viewed as a schematic that directs how information should be + represented, independent of any specific model implementation + constraints. + + 2. Its classes were designed to be independent of any specific + policy domain. For example, DiffServ and IPSec represent two + different policy domains. Each document which extends PCIM to + one of these domains will derive subclasses from the classes + and relationships defined in PCIM, in order to represent + extensions of a generic model to cover specific technical + domains. + + 3. It's an information model, which must be mapped to a specific + data model (native CIM schema, LDAP schema, MIB, whatever) + before it can be implemented. Derivative documents will map + the extended information models noted in item 2, above, to + specific types of data model implementations. + + + +Moore, et al. Standards Track [Page 60] + +RFC 3060 Policy Core Information Model February 2001 + + + Even though specific security requirements are not appropriate for + PCIM, specific security requirements MUST be defined for each + operational real- world application of PCIM. Just as there will be a + wide range of operational, real-world systems using PCIM, there will + also be a wide range of security requirements for these systems. + Some operational, real-world systems that are deployed using PCIM may + have extensive security requirements that impact nearly all classes + and subclasses utilized by such a system, while other systems' + security requirements might have very little impact. + + The derivative documents, discussed above, will create the context + for applying operational, real-world, system-level security + requirements against the various models which derive from PCIM. + + For example, in some real-world scenarios, the values associated with + certain properties, within certain instantiated classes, may + represent information associated with scarce, and/or costly (and + therefore valuable) resources. It may be the case that these values + must not be disclosed to, or manipulated by, unauthorized parties. + As long as the derived model remains an information model (as opposed + to a data model), it is not possible to discuss the data model- + specific tools and mechanisms that are available for achieving the + authentication and authorization implicit in a requirement that + restricts read and/or read- write access to these values. Therefore, + these mechanisms will need to be discussed in each of the data models + to which the derived information models are mapped. If there are any + general security requirements that can be identified and can be + applied across multiple types of data models, it would be appropriate + to discuss those at the information model level, rather than the data + model level. In any case, any identified security requirements that + are not dealt with in the information model document, MUST be dealt + with in the derivative data model documents. + + We can illustrate these points by extending the example from Section + 2. A real-world system that provides QoS Gold Service to John would + likely need to provide at least the following security-related + capabilities and mechanisms (see [12] for definitions of security + related terms): + + o Data integrity for the information (e.g., property values and + instantiated relationships) that specify that John gets QoS Gold + Service, from the point(s) that the information is entered into + the system to the point(s) where network components actually + provide that Service. + + o Authentication and Authorization methods to ensure that only + system administrators (and not John or other engineers) can + remotely administer components of the system. + + + +Moore, et al. Standards Track [Page 61] + +RFC 3060 Policy Core Information Model February 2001 + + + o An Authentication method to insure that John receives Gold + Service, and the other members of the engineering group receive + Bronze Service. + + These are one possible set of requirements associated with an example + real-world system which delivers Gold Service, and the appropriate + place to document these would be in some combination of the + information model and the derivative data models for QoS Policy. + Each of the data models would also need to discuss how these + requirements are satisfied, using the mechanisms typically available + to such a data model, given the particular technology or set of + technologies which it may employ. + +11. References + + [1] Distributed Management Task Force, Inc., "DMTF Technologies: CIM + Standards << CIM Schema: Version 2.4", available via links on + the following DMTF web page: + http://www.dmtf.org/spec/cim_schema_v24.html. + + [2] Distributed Management Task Force, Inc., "Common Information + Model (CIM) Specification, version 2.2, June 1999. This + document is available on the following DMTF web page: + http://www.dmtf.org/spec/cims.html. + + [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [4] Hovey, R. and S. Bradner, "The Organizations Involved in the + IETF Standards Process", BCP 11, RFC 2028, October 1996. + + [5] J. Strassner and S. Judd, "Directory-Enabled Networks", version + 3.0c5 (August 1998). A PDF file is available at + http://www.murchiso.com/den/#denspec. + + [6] J. Strassner, policy architecture BOF presentation, 42nd IETF + Meeting, Chicago, Illinois, October, 1998. Minutes of this BOF + are available at the following location: + http://www.ietf.org/proceedings/98aug/index.html. + + [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC + 2279, January 1998. + + [8] Levi, D. and J. Schoenwaelder, "Definitions of Managed Objects + for Scheduling Management Operations", RFC 2591, May 1999. + + [9] Yavatkar, R., Pendarakis, D. and R. Guerin, "A Framework for + Policy-based Admission Control", RFC 2753, January 2000. + + + +Moore, et al. Standards Track [Page 62] + +RFC 3060 Policy Core Information Model February 2001 + + + [10] Dawson, F. and D. Stenerson, "Internet Calendaring and + Scheduling Core Object Specification (iCalendar)", RFC 2445, + November 1998. + + [11] Strassner, J., and E. Ellesson, B. Moore, R. Moats, "Policy Core + LDAP Schema", Work in Progress. + + [12] Shirey, R., "Internet Security Glossary", FYI 36, RFC 2828, May + 2000. + + Note: the CIM 2.4 Schema specification is defined by the following + set of MOF files, available from the following URL: + + http://www.dmtf.org/spec/CIM_Schema24/CIM_Schema24.zip + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Moore, et al. Standards Track [Page 63] + +RFC 3060 Policy Core Information Model February 2001 + + +12. Authors' Addresses + + Ed Ellesson + LongBoard, Inc. + 2505 Meridian Pkwy, #100 + Durham, NC 27713 + + Phone: +1 919-361-3230 + Fax: +1 919-361-3299 + EMail: eellesson@lboard.com + + + Bob Moore + IBM Corporation, BRQA/502 + 4205 S. Miami Blvd. + Research Triangle Park, NC 27709 + + Phone: +1 919-254-4436 + Fax: +1 919-254-6243 + EMail: remoore@us.ibm.com + + + John Strassner + Cisco Systems, Bldg 15 + 170 West Tasman Drive + San Jose, CA 95134 + + Phone: +1 408-527-1069 + Fax: +1 408-527-6351 + EMail: johns@cisco.com + + + Andrea Westerinen + Cisco Systems + 170 West Tasman Drive + San Jose, CA 95134 + + Phone: +1 408-853-8294 + Fax: +1 408-527-6351 + EMail: andreaw@cisco.com + + + + + + + + + + + +Moore, et al. Standards Track [Page 64] + +RFC 3060 Policy Core Information Model February 2001 + + +13. Appendix A: Class Identification in a Native CIM Implementation + + While the CommonName property is present in the abstract superclass + Policy, and is thus available in all of its instantiable subclasses, + CIM does not use this property for naming instances. The following + subsections discuss how naming is handled in a native CIM + implementation for each of the instantiable classes in the Policy + Core Information Model. + + Two things should be noted regarding CIM naming: + + o When a CIM association is specified as "weak", this is a statement + about naming scopes: an instance of the class at the weak end of + the association is named within the scope of an instance of the + class at the other end of the association. This is accomplished + by propagation of keys from the instance of the scoping class to + the instance of the weak class. Thus the weak class has, via key + propagation, all the keys from the scoping class, and it also has + one or more additional keys for distinguishing instances of the + weak class, within the context of the scoping class. + + o All class names in CIM are limited to alphabetic and numeric + characters plus the underscore, with the restriction that the + first character cannot be numeric. Refer to Appendix F "Unicode + Usage" in reference [2] for an exact specification of how CIM + class names are encoded in CIM strings. + +13.1. Naming Instances of PolicyGroup and PolicyRule + + A policy group always exists in the context of a system. In the + Policy Core Information Model, this is captured by the weak + aggregation PolicyGroupInSystem between a PolicyGroup and a System. + Note that System serves as the base class for describing network + devices and administrative domains. + + A policy rule also exists in the context of a system. In the Policy + Core Information Model, this is captured by the weak association + PolicyRuleInSystem between a PolicyRule and a System. + + The following sections define the CIM keys for PolicyGroup and + PolicyRule. + +13.1.1. PolicyGroup's CIM Keys + + The CIM keys of the PolicyGroup class are: + + o SystemCreationClassName (A CIM_System key, propagated due to the + weak association, PolicyGroupInSystem) + + + +Moore, et al. Standards Track [Page 65] + +RFC 3060 Policy Core Information Model February 2001 + + + o SystemName (A CIM_System key, propagated due to the weak + association, PolicyGroupInSystem) + o CreationClassName + o PolicyGroupName + + They are defined in Reference [1] as follows: + + NAME SystemCreationClassName + DESCRIPTION SystemCreationClassName represents the class name of + the CIM System object providing the naming scope for + the instance of PolicyGroup. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME SystemName + DESCRIPTION SystemName represent the individual name of the + particular System object, providing the naming scope + for the instance of PolicyGroup. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME CreationClassName + DESCRIPTION This property is set to "CIM_PolicyGroup", if the + PolicyGroup object is directly instantiated. Or, it + is equal to the class name of the PolicyGroup + subclass that is instantiated. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyGroupName + DESCRIPTION The identifying name of this policy group. + SYNTAX string [MaxLen 256] + QUALIFIER key + +13.1.2. PolicyRule's CIM Keys + + The CIM keys of the PolicyRule class are: + + o SystemCreationClassName (A CIM_System key, propagated due to the + weak association PolicyRuleInSystem) + o SystemName (A CIM_System key, propagated due to the weak + association PolicyRuleInSystem) + o CreationClassName + o PolicyRuleName + + SystemCreationClassName and SystemName work the same as defined for + the class PolicyGroup. See Section 13.1.1 for details. + + + + +Moore, et al. Standards Track [Page 66] + +RFC 3060 Policy Core Information Model February 2001 + + + The other two properties are defined in Reference [1] as follows: + + NAME CreationClassName + DESCRIPTION This property is set to "CIM_PolicyRule", if the + PolicyRule object is directly instantiated. Or, + it is equal to the class name of the PolicyRule + subclass that is instantiated. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyRuleName + DESCRIPTION The identifying name of this policy rule. + SYNTAX string [MaxLen 256] + QUALIFIER key + +13.2. Naming Instances of PolicyCondition and Its Subclasses + + The CIM keys of the PolicyCondition class are: + + o SystemCreationClassName + o SystemName + o PolicyRuleCreationClassName + o PolicyRuleName + o CreationClassName + o PolicyConditionName + + Note that none of the keys are defined as propagated, although they + appear to fit this convention. The reason for this difference is + because (as indicated in Sections 5.1 and 6.4) the PolicyCondition + class is used to represent both reusable and rule-specific + conditions. This, in turn, affects what associations are valid for + an instance of PolicyCondition, and how that instance is named. + + In an ideal world, an instance of the PolicyCondition class would be + scoped either by its PolicyRepository (for a reusable condition) or + by its PolicyRule (for a rule-specific condition). However, CIM has + the restriction that a given class can only be "weak" to one other + class (i.e., defined by one weak association). + + To work within the restrictions of CIM naming, it is necessary to + "simulate" weak associations between PolicyCondition and PolicyRule, + and between PolicyCondition and PolicyRepository, through a technique + we'll call manual key propagation. Strictly speaking, manual key + propagation isn't key propagation at all. But it has the same effect + as (true) key propagation, so the name fits. + + + + + + +Moore, et al. Standards Track [Page 67] + +RFC 3060 Policy Core Information Model February 2001 + + + Figure 9 illustrates how manual propagation works in the case of + PolicyCondition. (Note that only the key properties are shown for + each of the classes.) In the figure, the line composed of 'I's + indicates class inheritance, the one composed of 'P's indicates + (true) key propagation via the weak aggregation PolicyRuleInSystem, + and the ones composed of 'M's indicate manual key propagation. + + +------------------+ + | System | + +------------------+ + |CreationClassName | + |Name | + +------------------+ + ^ P + I PPPPPPPPPPPPPPPPPPPPPPPPPPPP + I P + +------------------+ +---------------v--------------+ + | AdminDomain | | PolicyRule | + +------------------+ +------------------------------+ + |CreationClassName | | System.CreationClassName | + |Name | | System.Name | + +------------------+ | CreationClassName | + ^ | PolicyRuleName | + I +------------------------------+ + I M + I M + +------------------+ M + | PolicyRepository | M + +------------------+ M + |CreationClassName | M + |Name | M + +------------------+ M + M M + M M + M M + +----v-------------------v----+ + | PolicyCondition | + +-----------------------------+ + | SystemCreationClassName | + | SystemName | + | PolicyRuleCreationClassName | + | PolicyRuleName | + | CreationClassName | + | PolicyConditionName | + +-----------------------------+ + + Figure 9. Manual Key Propagation for Naming PolicyConditions + + + + +Moore, et al. Standards Track [Page 68] + +RFC 3060 Policy Core Information Model February 2001 + + + Looking at Figure 9, we see that two key properties, + CreationClassName and Name, are defined in the System class, and + inherited by its subclasses AdminDomain and PolicyRepository. Since + PolicyRule is weak to System, these two keys are propagated to it; it + also has its own keys CreationClassName and PolicyRuleName. + + A similar approach, though not automatic, is used in "manual key + propagation". Here is the approach for rule-specific and reusable + PolicyConditions: + + o The manual propagation of keys from PolicyRule to PolicyCondition + involves copying the values of PolicyRule's four key properties + into four similarly named key properties in PolicyCondition. From + the point of view of the CIM specification language, the property + SystemName in PolicyCondition is a completely new key property. + However, the relationship to the Name property in System is + defined in the description of SystemName. + + o The manual propagation of keys from PolicyRepository to + PolicyCondition works in exactly the same way for the first two + key properties. However, since PolicyRepository doesn't include + PolicyRule properties, the PolicyRuleCreationClassName and + PolicyRuleName have no values. A special value, "No Rule", is + assigned to both of these properties in this case, indicating that + this instance of PolicyCondition is not named within the scope of + any particular policy rule. + + The following section defines the specific CIM keys for + PolicyCondition. + +13.2.1. PolicyCondition's CIM Keys + + PolicyCondition's key properties are defined in Reference [1] as + follows: + + NAME SystemCreationClassName + DESCRIPTION SystemCreationClassName represents the class + name of the CIM System object providing the + naming scope for the instance of PolicyCondition. + For a rule-specific policy condition, this is the + type of system (e.g., the name of the class that + created this instance) in whose context the policy + rule is defined. For a reusable policy condition, + this is set to "CIM_PolicyRepository", if the + PolicyRepository object is directly instantiated. + Or, it is equal to the class name of the + PolicyRepository subclass that is instantiated. + SYNTAX string [MaxLen 256] + + + +Moore, et al. Standards Track [Page 69] + +RFC 3060 Policy Core Information Model February 2001 + + + QUALIFIER key + + NAME SystemName + DESCRIPTION The name of the System object in whose scope this + policy condition is defined. This property + completes the identification of the System object. + For a rule-specific policy condition, this is the + name of the instance of the system in whose + context the policy rule is defined. For a + reusable policy condition, this is name of the + instance of PolicyRepository that holds the policy + condition. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyRuleCreationClassName + DESCRIPTION For a rule-specific policy condition, this + property identifies the class name of the policy + rule instance, in whose scope this instance of + PolicyCondition exists. For a reusable policy + condition, this property is set to a special + value, "No Rule", indicating that this instance + of PolicyCondition is not unique to one policy + rule. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyRuleName + DESCRIPTION For a rule-specific policy condition, + PolicyRuleName completes the identification of + the PolicyRule object with which this condition + is associated. For a reusable policy condition, + a special value, "No Rule", is used to indicate + that this condition is reusable. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME CreationClassName + DESCRIPTION The class name of the PolicyCondition subclass + that is instantiated. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyConditionName + DESCRIPTION The identifying name of this policy condition. + SYNTAX string [MaxLen 256] + QUALIFIER key + + + + +Moore, et al. Standards Track [Page 70] + +RFC 3060 Policy Core Information Model February 2001 + + +13.3. Naming Instances of PolicyAction and Its Subclasses + + From the point of view of naming, the PolicyAction class and its + subclasses work exactly like the PolicyCondition class and its + subclasses. See Section 13.2 and 13.2.1 for details. + + Specifically, the CIM keys of PolicyAction are: + + o SystemCreationClassName + o SystemName + o PolicyRuleCreationClassName + o PolicyRuleName + o CreationClassName + o PolicyActionName + + They are defined in Reference [1] as follows: + + NAME SystemCreationClassName + DESCRIPTION SystemCreationClassName represents the class name + of the CIM System object providing the naming + scope for the instance of PolicyAction. For a + rule-specific policy action, this is the type of + system (e.g., the name of the class that created + this instance) in whose context the policy rule + is defined. For a reusable policy action, this + is set to "CIM_PolicyRepository", if the + PolicyRepository object is directly instantiated. + Or, it is equal to the class name of the + PolicyRepository subclass that is instantiated. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME SystemName + DESCRIPTION The name of the System object in whose scope this + policy action is defined. This property completes + the identification of the System object. For a + rule-specific policy action, this is the name of + the instance of the system in whose context the + policy rule is defined. For a reusable policy + action, this is name of the instance of + PolicyRepository that holds the policy action. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyRuleCreationClassName + DESCRIPTION For a rule-specific policy action, this property + identifies the class name of the policy rule + instance, in whose scope this instance of + + + +Moore, et al. Standards Track [Page 71] + +RFC 3060 Policy Core Information Model February 2001 + + + PolicyAction exists. For a reusable policy + action, this property is set to a special value, + "No Rule", indicating that this instance of + PolicyAction is not unique to one policy rule. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyRuleName + DESCRIPTION For a rule-specific policy action, PolicyRuleName + completes the identification of the PolicyRule + object with which this action is associated. For + a reusable policy action, a special value, "No + Rule", is used to indicate that this action is + reusable. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME CreationClassName + DESCRIPTION The class name of the PolicyAction subclass that is + instantiated. + SYNTAX string [MaxLen 256] + QUALIFIER key + + NAME PolicyActionName + DESCRIPTION The identifying name of this policy action. + SYNTAX string [MaxLen 256] + QUALIFIER key + +13.4. Naming Instances of PolicyRepository + + An instance of PolicyRepository is named by the two key properties + CreationClassName and Name that it inherits from its superclass + AdminDomain. These properties are actually defined in AdminDomain's + superclass, System, and then inherited by AdminDomain. + + For instances of PolicyRepository itself, the value of + CreationClassName must be "CIM_PolicyRepository". (Recall that for + readability the prefix "CIM_" has been omitted from all class names + in this document). If a subclass of PolicyRepository (perhaps + QosPolicyRepository) is defined and instantiated, then the class name + "CIM_QosPolicyRepository" is used in CreationClassName. + + The Name property simply completes the identification of the instance + of PolicyRepository. + + + + + + + +Moore, et al. Standards Track [Page 72] + +RFC 3060 Policy Core Information Model February 2001 + + +13.5. Role of the CreationClassName Property in Naming + + To provide for more flexibility in instance naming, CIM makes use of + a property called CreationClassName. The idea of CreationClassName + is to provide another dimension that can be used to avoid naming + collisions, in the specific case of instances belonging to two + different subclasses of a common superclass. An example will + illustrate how CreationClassName works. + + Suppose we have instances of two different subclasses of + PolicyCondition, FrameRelayPolicyCondition and BgpPolicyCondition, + and that these instances apply to the same context. If we had only + the single key property PolicyConditionName available for + distinguishing the two instances, then a collision would result from + naming both of the instances with the key value PCName = "PC-1". + Thus policy administrators from widely different disciplines would + have to coordinate their naming of PolicyConditions for this context. + + With CreationClassName, collisions of this type can be eliminated, + without requiring coordination among the policy administrators. The + two instances can be distinguished by giving their CreationClassNames + different values. One instance is now identified with the two keys + + CreationClassName = "FrameRelayPolicyCondition" + PCName = "PC-1", + + while the other is identified with + + CreationClassName = "BgpPolicyCondition" + PCName = "PC-1". + + Each of the instantiable classes in the Core Model includes the + CreationClassName property as a key in addition to its own class- + specific key property. + +13.6. Object References + + Today, all CIM associations involve two object references. CIM + decomposes an object reference into two parts: a high-order part + that identifies an object manager and namespace, and a model path + that identifies an object instance within a namespace. The model + path, in turn, can be decomposed into an object class identifier and + a set of key values needed to identify an instance of that class. + + Because the object class identifier is part of the model path, a CIM + object reference is strongly typed. The GroupComponent object + reference in the PolicyGroupInPolicyGroup association, for example, + can only point to an instance of PolicyGroup, or to an instance of a + + + + + +Moore, et al. Standards Track [Page 73] + +RFC 3060 Policy Core Information Model February 2001 + + + subclass of PolicyGroup. Contrast this with LDAP, where a DN pointer + is completely untyped: it identifies (by DN) an entry, but places no + restriction on that entry's object class(es). + + An important difference between CIM property definitions and LDAP + attribute type definitions was identified earlier in Section 6: + while an LDAP attribute type definition has global scope, a CIM + property definition applies only to the class in which it is defined. + Thus properties having the same name in two different classes are + free to have different data types. CIM takes advantage of this + flexibility by allowing the data type of an object reference to be + overridden in a subclass of the association class in which it was + initially defined. + + For example, the object reference GroupComponent is defined in the + abstract aggregation class PolicyComponent to be a reference to an + instance of the class Policy. This data type for GroupComponent is + then overridden in subclasses of PolicyComponent. In + PolicyGroupInPolicyGroup, for example, GroupComponent becomes a + reference to an instance of PolicyGroup. But in + PolicyConditionInPolicyRule it becomes a reference to an instance of + PolicyRule. Of course there is not total freedom in this overriding + of object references. In order to remain consistent with its + abstract superclass, a subclass of PolicyComponent can only override + GroupComponent to be a reference to a subclass of Policy. A Policy + class is the generic context for the GroupComponent reference in + PolicyComponent. + + + + + + + + + + + + + + + + + + + + + + + + +Moore, et al. Standards Track [Page 74] + +RFC 3060 Policy Core Information Model February 2001 + + +14. Appendix B: The Core Policy MOF + +// ================================================================== +// Title: Core Policy MOF Specification 2.4 +// Filename: CIM_Policy24.MOF +// Version: 2.4 +// Release: 0 +// Description: The object classes below are listed in an order that +// avoids forward references. Required objects, defined +// by other working groups, are omitted. +// Date: 06/27/2000 +// CIMCR516a - Rooted the model associations under Policy +// Component or PolicyInSystem. Corrected PolicyCondition/ +// PolicyActionInPolicyRepository to subclass from +// PolicyInSystem (similar to Groups and Roles 'InSystem') +// ================================================================== +// Author: DMTF SLA (Service Level Agreement) Working Group +// ================================================================== +// Pragmas +// ================================================================== +#pragma Locale ("en-US") + + +// ================================================================== +// Policy +// ================================================================== + [Abstract, Description ( + "An abstract class describing common properties of all " + "policy rule-related subclasses, such as PolicyGroup, Policy" + "Rule and PolicyCondition. All instances of policy rule-" + "related entities will be created from subclasses of CIM_" + "Policy. The exception to this statement is PolicyRepository " + "which is a type of CIM_System.") + ] +class CIM_Policy : CIM_ManagedElement +{ + [Description ( + "A user-friendly name of this policy-related object.") + ] + string CommonName; + [Description ( + "An array of keywords for characterizing / categorizing " + "policy objects. Keywords are of one of two types: \n" + " o Keywords defined in this and other MOFs, or in DMTF " + " white papers. These keywords provide a vendor-" + " independent, installation-independent way of " + " characterizing policy objects. \n" + " o Installation-dependent keywords for characterizing " + + + +Moore, et al. Standards Track [Page 75] + +RFC 3060 Policy Core Information Model February 2001 + + + " policy objects. Examples include 'Engineering', " + " 'Billing', and 'Review in December 2000'. \n" + "This MOF defines the following keywords: 'UNKNOWN', " + "'CONFIGURATION', 'USAGE', 'SECURITY', 'SERVICE', " + "'MOTIVATIONAL', 'INSTALLATION', and 'EVENT'. These " + "concepts are self-explanatory and are further discussed " + "in the SLA/Policy White Paper. One additional keyword " + "is defined: 'POLICY'. The role of this keyword is to " + "identify policy-related instances that may not be otherwise " + "identifiable, in some implementations. The keyword 'POLICY' " + "is NOT mutually exclusive of the other keywords " + "specified above.") + ] + string PolicyKeywords []; +}; + +// ================================================================== +// PolicyComponent +// ================================================================== + [Association, Abstract, Aggregation, Description ( + "CIM_PolicyComponent is a generic association used to " + "establish 'part of' relationships between the subclasses of " + "CIM_Policy. For example, the PolicyConditionInPolicyRule " + "association defines that PolicyConditions are part of a " + "PolicyRule.") + ] +class CIM_PolicyComponent +{ + [Aggregate, Key, Description ( + "The parent Policy in the association.") + ] + CIM_Policy REF GroupComponent; + [Key, Description ( + "The child/part Policy in the association.") + ] + CIM_Policy REF PartComponent; +}; + +// ================================================================== +// PolicyInSystem +// ================================================================== + [Association, Abstract, Description ( + " CIM_PolicyInSystem is a generic association used to " + "establish dependency relationships between Policies and the " + "Systems that host them. These Systems may be ComputerSystems " + "where Policies are 'running' or they may be Policy" + "Repositories where Policies are stored. This relationship " + "is similar to the concept of CIM_Services being dependent " + + + +Moore, et al. Standards Track [Page 76] + +RFC 3060 Policy Core Information Model February 2001 + + + "on CIM_Systems as defined by the HostedService " + "association. \n" + " Cardinality is Max(1) for the Antecedent/System " + "reference since Policies can only be hosted in at most one " + "System context. Some subclasses of the association will " + "further refine this definition to make the Policies Weak " + "to Systems. Other subclasses of PolicyInSystem will " + "define an optional hosting relationship. Examples of each " + "of these are the PolicyRuleInSystem and PolicyConditionIn" + "PolicyRepository associations, respectively.") + ] +class CIM_PolicyInSystem : CIM_Dependency +{ + [Override ("Antecedent"), Max (1), Description ( + "The hosting System.") + ] + CIM_System REF Antecedent; + [Override ("Dependent"), Description ( + "The hosted Policy.") + ] + CIM_Policy REF Dependent; +}; + +// ================================================================== +// PolicyGroup +// ================================================================== + [Description ( + "A container for either a set of related PolicyGroups " + "or a set of related PolicyRules, but not both. Policy" + "Groups are defined and named relative to the CIM_System " + "which provides their context.") + ] +class CIM_PolicyGroup : CIM_Policy +{ + [Propagated("CIM_System.CreationClassName"), + Key, MaxLen (256), + Description ("The scoping System's CreationClassName.") + ] + string SystemCreationClassName; + [Propagated("CIM_System.Name"), + Key, MaxLen (256), + Description ("The scoping System's Name.") + ] + string SystemName; + [Key, MaxLen (256), Description ( + "CreationClassName indicates the name of the class or the " + "subclass used in the creation of an instance. When used " + "with the other key properties of this class, this property " + + + +Moore, et al. Standards Track [Page 77] + +RFC 3060 Policy Core Information Model February 2001 + + + "allows all instances of this class and its subclasses to " + "be uniquely identified.") ] + string CreationClassName; + [Key, MaxLen (256), Description ( + "A user-friendly name of this PolicyGroup.") + ] + string PolicyGroupName; +}; + +// ================================================================== +// PolicyGroupInPolicyGroup +// ================================================================== + [Association, Aggregation, Description ( + "A relationship that aggregates one or more lower-level " + "PolicyGroups into a higher-level Group. A Policy" + "Group may aggregate either PolicyRules or other Policy" + "Groups, but not both.") + ] +class CIM_PolicyGroupInPolicyGroup : CIM_PolicyComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "A PolicyGroup that aggregates other Groups.") + ] + CIM_PolicyGroup REF GroupComponent; + [Override ("PartComponent"), Description ( + "A PolicyGroup aggregated by another Group.") + ] + CIM_PolicyGroup REF PartComponent; +}; + +// ================================================================== +// PolicyGroupInSystem +// ================================================================== + [Association, Description ( + "An association that links a PolicyGroup to the System " + "in whose scope the Group is defined.") + ] +class CIM_PolicyGroupInSystem : CIM_PolicyInSystem +{ + [Override ("Antecedent"), Min(1), Max(1), Description ( + "The System in whose scope a PolicyGroup is defined.") + ] + CIM_System REF Antecedent; + [Override ("Dependent"), Weak, Description ( + "A PolicyGroup named within the scope of a System.") + ] + CIM_PolicyGroup REF Dependent; +}; + + + +Moore, et al. Standards Track [Page 78] + +RFC 3060 Policy Core Information Model February 2001 + + +// ================================================================== +// PolicyRule +// ================================================================== + [Description ( + " The central class for representing the 'If Condition then " + "Action' semantics associated with a policy rule. " + "A PolicyRule condition, in the most general sense, is " + "represented as either an ORed set of ANDed conditions " + "(Disjunctive Normal Form, or DNF) or an ANDed set of ORed " + "conditions (Conjunctive Normal Form, or CNF). Individual " + "conditions may either be negated (NOT C) or unnegated (C). " + "The actions specified by a PolicyRule are to be performed " + "if and only if the PolicyRule condition (whether it is " + "represented in DNF or CNF) evaluates to TRUE.\n\n" + " " + "The conditions and actions associated with a PolicyRule " + "are modeled, respectively, with subclasses of Policy" + "Condition and PolicyAction. These condition and action " + "objects are tied to instances of PolicyRule by the Policy" + "ConditionInPolicyRule and PolicyActionInPolicyRule " + "aggregations.\n\n" + " " + "A PolicyRule may also be associated with one or more policy " + "time periods, indicating the schedule according to which the " + "policy rule is active and inactive. In this case it is the " + "PolicyRuleValidityPeriod aggregation that provides this " + "linkage.\n\n" + " " + "The PolicyRule class uses the property ConditionListType, to " + "indicate whether the conditions for the rule are in DNF or " + "CNF. The PolicyConditionInPolicyRule aggregation contains " + "two additional properties to complete the representation of " + "the Rule's conditional expression. The first of these " + "properties is an integer to partition the referenced " + "PolicyConditions into one or more groups, and the second is a " + "Boolean to indicate whether a referenced Condition is " + "negated. An example shows how ConditionListType and these " + "two additional properties provide a unique representation " + "of a set of PolicyConditions in either DNF or CNF.\n\n" + " " + "Suppose we have a PolicyRule that aggregates five " + "PolicyConditions C1 through C5, with the following values " + "in the properties of the five PolicyConditionInPolicyRule " + "associations:\n" + " C1: GroupNumber = 1, ConditionNegated = FALSE\n " + " C2: GroupNumber = 1, ConditionNegated = TRUE\n " + " C3: GroupNumber = 1, ConditionNegated = FALSE\n " + " C4: GroupNumber = 2, ConditionNegated = FALSE\n " + + + +Moore, et al. Standards Track [Page 79] + +RFC 3060 Policy Core Information Model February 2001 + + + " C5: GroupNumber = 2, ConditionNegated = FALSE\n\n " + " " + "If ConditionListType = DNF, then the overall condition for " + "the PolicyRule is:\n" + " (C1 AND (NOT C2) AND C3) OR (C4 AND C5)\n\n" + " " + "On the other hand, if ConditionListType = CNF, then the " + "overall condition for the PolicyRule is:\n" + " (C1 OR (NOT C2) OR C3) AND (C4 OR C5)\n\n" + " " + "In both cases, there is an unambiguous specification of " + "the overall condition that is tested to determine whether " + "to perform the PolicyActions associated with the PolicyRule.") + ] +class CIM_PolicyRule : CIM_Policy +{ + [Propagated("CIM_System.CreationClassName"), + Key, MaxLen (256), + Description ("The scoping System's CreationClassName.") + ] + string SystemCreationClassName; + [Propagated("CIM_System.Name"), + Key, MaxLen (256), + Description ("The scoping System's Name.") + ] + string SystemName; + [Key, MaxLen (256), Description ( + "CreationClassName indicates the name of the class or the " + "subclass used in the creation of an instance. When used " + "with the other key properties of this class, this property " + "allows all instances of this class and its subclasses to " + "be uniquely identified.") ] + string CreationClassName; + [Key, MaxLen (256), Description ( + "A user-friendly name of this PolicyRule.") + ] + string PolicyRuleName; + [Description ( + "Indicates whether this PolicyRule is administratively " + "enabled, administratively disabled, or enabled for " + "debug. When the property has the value 3 (\"enabledFor" + "Debug\"), the entity evaluating the PolicyConditions is " + "instructed to evaluate the conditions for the Rule, but not " + "to perform the actions if the PolicyConditions evaluate to " + "TRUE. This serves as a debug vehicle when attempting to " + "determine what policies would execute in a particular " + "scenario, without taking any actions to change state " + "during the debugging. The default value is 1 + + + +Moore, et al. Standards Track [Page 80] + +RFC 3060 Policy Core Information Model February 2001 + + +(\"enabled\")."), + ValueMap { "1", "2", "3" }, + Values { "enabled", "disabled", "enabledForDebug" } + ] + uint16 Enabled; + [Description ( + "Indicates whether the list of PolicyConditions " + "associated with this PolicyRule is in disjunctive " + "normal form (DNF) or conjunctive normal form (CNF)." + "The default value is 1 (\"DNF\")."), + ValueMap { "1", "2" }, + Values { "DNF", "CNF" } + ] + uint16 ConditionListType; + [Description ( + "A free-form string that can be used to provide " + "guidelines on how this PolicyRule should be used.") + ] + string RuleUsage; + [Description ( + "A non-negative integer for prioritizing this Policy" + "Rule relative to other Rules. A larger value " + "indicates a higher priority. The default value is 0.") + ] + uint16 Priority; + [Description ( + "A flag indicating that the evaluation of the Policy" + "Conditions and execution of PolicyActions (if the " + "Conditions evaluate to TRUE) is required. The " + "evaluation of a PolicyRule MUST be attempted if the " + "Mandatory property value is TRUE. If the Mandatory " + "property is FALSE, then the evaluation of the Rule " + "is 'best effort' and MAY be ignored.") + ] + boolean Mandatory; + [Description ( + "This property gives a policy administrator a way " + "of specifying how the ordering of the PolicyActions " + "associated with this PolicyRule is to be interpreted. " + "Three values are supported:\n" + " o mandatory(1): Do the actions in the indicated " + " order, or don't do them at all.\n" + " o recommended(2): Do the actions in the indicated " + " order if you can, but if you can't do them in this " + " order, do them in another order if you can.\n" + " o dontCare(3): Do them -- I don't care about the " + " order.\n" + "The default value is 3 (\"dontCare\")."), + + + +Moore, et al. Standards Track [Page 81] + +RFC 3060 Policy Core Information Model February 2001 + + + ValueMap { "1", "2", "3" }, + Values { "mandatory", "recommended", "dontCare" } + ] + uint16 SequencedActions; + [Description ( + "This property represents the roles and role combinations " + "associated with a PolicyRule. Each value represents one " + "role or role combination. Since this is a multi-valued " + "property, more than one role or combination can be associated " + "with a single policy rule. Each value is a string of the " + "form:\n" + " <RoleName>[&&<RoleName>]*\n" + "where the individual role names appear in alphabetical order " + "(according to the collating sequence for UCS-2).") + ] + string PolicyRoles []; +}; + +// ================================================================== +// PolicyRuleInPolicyGroup +// ================================================================== + [Association, Aggregation, Description ( + "A relationship that aggregates one or more PolicyRules " + "into a PolicyGroup. A PolicyGroup may aggregate either " + "PolicyRules or other PolicyGroups, but not both.") + ] +class CIM_PolicyRuleInPolicyGroup : CIM_PolicyComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "A PolicyGroup that aggregates one or more PolicyRules.") + ] + CIM_PolicyGroup REF GroupComponent; + [Override ("PartComponent"), Description ( + "A PolicyRule aggregated by a PolicyGroup.") + ] + CIM_PolicyRule REF PartComponent; +}; + +// ================================================================== +// PolicyRuleInSystem +// ================================================================== + [Association, Description ( + "An association that links a PolicyRule to the System " + "in whose scope the Rule is defined.") + ] +class CIM_PolicyRuleInSystem : CIM_PolicyInSystem +{ + [Override ("Antecedent"), Min(1), Max(1), Description ( + + + +Moore, et al. Standards Track [Page 82] + +RFC 3060 Policy Core Information Model February 2001 + + + "The System in whose scope a PolicyRule is defined.") + ] + CIM_System REF Antecedent; + [Override ("Dependent"), Weak, Description ( + "A PolicyRule named within the scope of a System.") + ] + CIM_PolicyRule REF Dependent; +}; + +// ================================================================== +// PolicyRepository +// ================================================================== + [Description ( + "A class representing an administratively defined " + "container for reusable policy-related information. " + "This class does not introduce any additional " + "properties beyond those in its superclass " + "AdminDomain. It does, however, participate in a " + "number of unique associations." + "\n\n" + "An instance of this class uses the NameFormat value" + "\"PolicyRepository\", which is defined in the AdminDomain" + "class.") + ] +class CIM_PolicyRepository : CIM_AdminDomain +{ +}; + +// ================================================================== +// PolicyRepositoryInPolicyRepository +// ================================================================== + [Association, Aggregation, Description ( + "A relationship that aggregates one or more lower-level " + "PolicyRepositories into a higher-level Repository.") + ] +class CIM_PolicyRepositoryInPolicyRepository : CIM_SystemComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "A PolicyRepository that aggregates other Repositories.") + ] + CIM_PolicyRepository REF GroupComponent; + [Override ("PartComponent"), Description ( + "A PolicyRepository aggregated by another Repository.") + ] + CIM_PolicyRepository REF PartComponent; +}; + +// ================================================================== + + + +Moore, et al. Standards Track [Page 83] + +RFC 3060 Policy Core Information Model February 2001 + + +// PolicyCondition +// ================================================================== + [Abstract, Description ( + "A class representing a rule-specific or reusable policy " + "condition to be evaluated in conjunction with a Policy" + "Rule. Since all operational details of a PolicyCondition " + "are provided in subclasses of this object, this class is " + "abstract.") + ] +class CIM_PolicyCondition : CIM_Policy +{ + [Key, MaxLen (256), Description ( + " The name of the class or the subclass used in the " + "creation of the System object in whose scope this " + "PolicyCondition is defined.\n\n" + " " + "This property helps to identify the System object in " + "whose scope this instance of PolicyCondition exists. " + "For a rule-specific PolicyCondition, this is the System " + "in whose context the PolicyRule is defined. For a " + "reusable PolicyCondition, this is the instance of " + "PolicyRepository (which is a subclass of System) that " + "holds the Condition.\n\n" + " " + "Note that this property, and the analogous property " + "SystemName, do not represent propagated keys from an " + "instance of the class System. Instead, they are " + "properties defined in the context of this class, which " + "repeat the values from the instance of System to which " + "this PolicyCondition is related, either directly via the " + "PolicyConditionInPolicyRepository aggregation or indirectly " + "via the PolicyConditionInPolicyRule aggregation.") + ] + string SystemCreationClassName; + [Key, MaxLen (256), Description ( + " The name of the System object in whose scope this " + "PolicyCondition is defined.\n\n" + " " + "This property completes the identification of the System " + "object in whose scope this instance of PolicyCondition " + "exists. For a rule-specific PolicyCondition, this is the " + "System in whose context the PolicyRule is defined. For a " + "reusable PolicyCondition, this is the instance of " + "PolicyRepository (which is a subclass of System) that " + "holds the Condition.") + ] + string SystemName; + [Key, MaxLen (256), Description ( + + + +Moore, et al. Standards Track [Page 84] + +RFC 3060 Policy Core Information Model February 2001 + + + "For a rule-specific PolicyCondition, the " + "CreationClassName of the PolicyRule object with which " + "this Condition is associated. For a reusable Policy" + "Condition, a special value, 'NO RULE', should be used to " + "indicate that this Condition is reusable and not " + "associated with a single PolicyRule.") + ] + string PolicyRuleCreationClassName; + [Key, MaxLen (256), Description ( + "For a rule-specific PolicyCondition, the name of " + "the PolicyRule object with which this Condition is " + "associated. For a reusable PolicyCondition, a " + "special value, 'NO RULE', should be used to indicate " + "that this Condition is reusable and not associated " + "with a single PolicyRule.") + ] + string PolicyRuleName; + [Key, MaxLen (256), Description ( + "CreationClassName indicates the name of the class or the " + "subclass used in the creation of an instance. When used " + "with the other key properties of this class, this property " + "allows all instances of this class and its subclasses to " + "be uniquely identified.") ] + string CreationClassName; + [Key, MaxLen (256), Description ( + "A user-friendly name of this PolicyCondition.") + ] + string PolicyConditionName; +}; + +// ================================================================== +// PolicyConditionInPolicyRule +// ================================================================== + [Association, Aggregation, Description ( + " A PolicyRule aggregates zero or more instances of the " + "PolicyCondition class, via the PolicyConditionInPolicyRule " + "association. A Rule that aggregates zero Conditions is not " + "valid -- it may, however, be in the process of being entered " + "into a PolicyRepository or being defined for a System. Note " + "that a PolicyRule should have no effect until it is valid.\n\n" + " " + "The Conditions aggregated by a PolicyRule are grouped into " + "two levels of lists: either an ORed set of ANDed sets of " + "conditions (DNF, the default) or an ANDed set of ORed sets " + "of conditions (CNF). Individual PolicyConditions in these " + "lists may be negated. The property ConditionListType " + "specifies which of these two grouping schemes applies to a " + "particular PolicyRule.\n\n" + + + +Moore, et al. Standards Track [Page 85] + +RFC 3060 Policy Core Information Model February 2001 + + + " " + "In either case, PolicyConditions are used to determine whether " + "to perform the PolicyActions associated with the +PolicyRule.\n\n" + " " + "One or more PolicyTimePeriodConditions may be among the " + "conditions associated with a PolicyRule via the Policy" + "ConditionInPolicyRule association. In this case, the time " + "periods are simply additional Conditions to be evaluated " + "along with any others that are specified for the Rule. ") + ] +class CIM_PolicyConditionInPolicyRule : CIM_PolicyComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "This property represents the PolicyRule that " + "contains one or more PolicyConditions.") + ] + CIM_PolicyRule REF GroupComponent; + [Override ("PartComponent"), Description ( + "This property holds the name of a PolicyCondition " + "contained by one or more PolicyRules.") + ] + CIM_PolicyCondition REF PartComponent; + [Description ( + "Unsigned integer indicating the group to which the " + "PolicyCondition identified by the ContainedCondition " + "property belongs. This integer segments the Conditions " + "into the ANDed sets (when the ConditionListType is " + "\"DNF\") or similarly the ORed sets (when the Condition" + "ListType is \"CNF\") that are then evaluated.") + ] + uint16 GroupNumber; + [Description ( + "Indication of whether the Condition identified by " + "the ContainedCondition property is negated. TRUE " + "indicates that the PolicyCondition IS negated, FALSE " + "indicates that it IS NOT negated.") + ] + boolean ConditionNegated; +}; + +// ================================================================== +// PolicyConditionInPolicyRepository +// ================================================================== + [Association, Description ( + " A class representing the hosting of reusable " + "PolicyConditions by a PolicyRepository. A reusable Policy" + "Condition is always related to a single PolicyRepository, " + + + +Moore, et al. Standards Track [Page 86] + +RFC 3060 Policy Core Information Model February 2001 + + + "via this aggregation.\n\n" + " " + "Note, that an instance of PolicyCondition can be either " + "reusable or rule-specific. When the Condition is rule-" + "specific, it shall not be related to any " + "PolicyRepository via the PolicyConditionInPolicyRepository " + "aggregation.") + ] +class CIM_PolicyConditionInPolicyRepository : CIM_PolicyInSystem +{ + [Override ("Antecedent"), Max(1), Description ( + "This property identifies a PolicyRepository " + "hosting one or more PolicyConditions. A reusable " + "PolicyCondition is always related to exactly one " + "PolicyRepository via the PolicyConditionInPolicyRepository " + "aggregation. The [0..1] cardinality for this property " + "covers the two types of PolicyConditions: 0 for a " + "rule-specific PolicyCondition, 1 for a reusable one.") + ] + CIM_PolicyRepository REF Antecedent; + [Override ("Dependent"), Description ( + "This property holds the name of a PolicyCondition" + "hosted in the PolicyRepository. ") + ] + CIM_PolicyCondition REF Dependent; +}; + +// ================================================================== +// PolicyTimePeriodCondition +// ================================================================== + [Description ( + " This class provides a means of representing the time " + "periods during which a PolicyRule is valid, i.e., active. " + "At all times that fall outside these time periods, the " + "PolicyRule has no effect. A Rule is treated as valid " + "at ALL times, if it does not specify a " + "PolicyTimePeriodCondition.\n\n" + " " + "In some cases a Policy Consumer may need to perform " + "certain setup / cleanup actions when a PolicyRule becomes " + "active / inactive. For example, sessions that were " + "established while a Rule was active might need to " + "be taken down when the Rule becomes inactive. In other " + "cases, however, such sessions might be left up. In this " + "case, the effect of deactivating the PolicyRule would " + "just be to prevent the establishment of new sessions. \n\n" + " " + "Setup / cleanup behaviors on validity period " + + + +Moore, et al. Standards Track [Page 87] + +RFC 3060 Policy Core Information Model February 2001 + + + "transitions are not currently addressed by the Policy " + "Model, and must be specified in 'guideline' documents or " + "via subclasses of CIM_PolicyRule, CIM_PolicyTimePeriod" + "Condition or other concrete subclasses of CIM_Policy. If " + "such behaviors need to be under the control of the policy " + "administrator, then a mechanism to allow this control " + "must also be specified in the subclasses.\n\n" + " " + "PolicyTimePeriodCondition is defined as a subclass of " + "PolicyCondition. This is to allow the inclusion of " + "time-based criteria in the AND/OR condition definitions " + "for a PolicyRule.\n\n" + " " + "Instances of this class may have up to five properties " + "identifying time periods at different levels. The values " + "of all the properties present in an instance are ANDed " + "together to determine the validity period(s) for the " + "instance. For example, an instance with an overall " + "validity range of January 1, 2000 through December 31, " + "2000; a month mask that selects March and April; a " + "day-of-the-week mask that selects Fridays; and a time " + "of day range of 0800 through 1600 would be represented " + "using the following time periods:\n" + " Friday, March 5, 2000, from 0800 through 1600;\n " + " Friday, March 12, 2000, from 0800 through 1600;\n " + " Friday, March 19, 2000, from 0800 through 1600;\n " + " Friday, March 26, 2000, from 0800 through 1600;\n " + " Friday, April 2, 2000, from 0800 through 1600;\n " + " Friday, April 9, 2000, from 0800 through 1600;\n " + " Friday, April 16, 2000, from 0800 through 1600;\n " + " Friday, April 23, 2000, from 0800 through 1600;\n " + " Friday, April 30, 2000, from 0800 through 1600.\n\n" + " " + "Properties not present in an instance of " + "PolicyTimePeriodCondition are implicitly treated as having " + "their value 'always enabled'. Thus, in the example above, " + "the day-of-the-month mask is not present, and so the " + "validity period for the instance implicitly includes a " + "day-of-the-month mask that selects all days of the month. " + "If this 'missing property' rule is applied to its fullest, we " + "see that there is a second way to indicate that a Policy" + "Rule is always enabled: associate with it an instance of " + "PolicyTimePeriodCondition whose only properties with " + "specific values are its key properties.") + ] +class CIM_PolicyTimePeriodCondition : CIM_PolicyCondition +{ + [Description ( + + + +Moore, et al. Standards Track [Page 88] + +RFC 3060 Policy Core Information Model February 2001 + + + " This property identifies an overall range of calendar " + "dates and times over which a PolicyRule is valid. It is " + "formatted as a string representing a start date and time, " + "in which the character 'T' indicates the beginning of the " + "time portion, followed by the solidus character '/', " + "followed by a similar string representing an end date and " + "time. The first date indicates the beginning of the range, " + "while the second date indicates the end. Thus, the second " + "date and time must be later than the first. Date/times are " + "expressed as substrings of the form yyyymmddThhmmss. For " + "example: \n" + " 20000101T080000/20000131T120000 defines \n" + " January 1, 2000, 0800 through January 31, 2000, noon\n\n" + " " + "There are also two special cases in which one of the " + "date/time strings is replaced with a special string defined " + "in RFC 2445.\n " + " o If the first date/time is replaced with the string " + " 'THISANDPRIOR', then the property indicates that a " + " PolicyRule is valid [from now] until the date/time " + " that appears after the '/'.\n" + " o If the second date/time is replaced with the string " + " 'THISANDFUTURE', then the property indicates that a " + " PolicyRule becomes valid on the date/time that " + " appears before the '/', and remains valid from that " + " point on. "), + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.MonthOfYearMask", + "CIM_PolicyTimePeriodCondition.DayOfMonthMask", + "CIM_PolicyTimePeriodCondition.DayOfWeekMask", + "CIM_PolicyTimePeriodCondition.TimeOfDayMask", + "CIM_PolicyTimePeriodCondition.LocalOrUtcTime"} + ] + string TimePeriod; + [Octetstring, Description ( + " The purpose of this property is to refine the valid time " + "period that is defined by the TimePeriod property, by " + "explicitly specifying in which months the PolicyRule is " + "valid. These properties work together, with the " + "TimePeriod used to specify the overall time period in " + "which the PolicyRule is valid, and the MonthOfYearMask used " + "to pick out the months during which the Rule is valid.\n\n" + " " + "This property is formatted as an octet string, structured " + "as follows:\n" + " o a 4-octet length field, indicating the length of the " + " entire octet string; this field is always set to " + " 0x00000006 for this property;\n" + + + +Moore, et al. Standards Track [Page 89] + +RFC 3060 Policy Core Information Model February 2001 + + + " o a 2-octet field consisting of 12 bits identifying the " + " 12 months of the year, beginning with January and " + " ending with December, followed by 4 bits that are " + " always set to '0'. For each month, the value '1' " + " indicates that the policy is valid for that month, " + " and the value '0' indicates that it is not valid.\n\n" + " " + "The value 0x000000060830, for example, indicates that a " + "PolicyRule is valid only in the months May, November, " + "and December.\n\n" + " " + "If a value for this property is not provided, then the " + "PolicyRule is treated as valid for all twelve months, and " + "only restricted by its TimePeriod property value and the " + "other Mask properties."), + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.TimePeriod", + "CIM_PolicyTimePeriodCondition.LocalOrUtcTime"} + ] + uint8 MonthOfYearMask[]; + [Octetstring, Description ( + " The purpose of this property is to refine the valid time " + "period that is defined by the TimePeriod property, by " + "explicitly specifying in which days of the month the Policy" + "Rule is valid. These properties work together, " + "with the TimePeriod used to specify the overall time period " + "in which the PolicyRule is valid, and the DayOfMonthMask used " + "to pick out the days of the month during which the Rule " + "is valid.\n\n " + " " + "This property is formatted as an octet string, structured " + "as follows:\n" + " o a 4-octet length field, indicating the length of the " + " entire octet string; this field is always set to " + " 0x0000000C for this property; \n" + " o an 8-octet field consisting of 31 bits identifying " + " the days of the month counting from the beginning, " + " followed by 31 more bits identifying the days of the " + " month counting from the end, followed by 2 bits that " + " are always set to '0'. For each day, the value '1' " + " indicates that the policy is valid for that day, and " + " the value '0' indicates that it is not valid. \n\n" + " " + "The value 0x0000000C8000000100000000, for example, " + "indicates that a PolicyRule is valid on the first and " + "last days of the month.\n\n " + " " + "For months with fewer than 31 days, the digits corresponding " + + + +Moore, et al. Standards Track [Page 90] + +RFC 3060 Policy Core Information Model February 2001 + + + "to days that the months do not have (counting in both " + "directions) are ignored.\n\n" + " " + "If a value for this property is not provided, then the " + "PolicyRule is treated as valid for all days of the month, and " + "only restricted by its TimePeriod property value and the " + "other Mask properties."), + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.TimePeriod", + "CIM_PolicyTimePeriodCondition.LocalOrUtcTime"} + ] + uint8 DayOfMonthMask[]; + [Octetstring, Description ( + " The purpose of this property is to refine the valid time " + "period that is defined by the TimePeriod property, by " + "explicitly specifying in which days of the month the Policy" + "Rule is valid. These properties work together, " + "with the TimePeriod used to specify the overall time period " + "in which the PolicyRule is valid, and the DayOfWeekMask used " + "to pick out the days of the week during which the Rule " + "is valid.\n\n " + " " + "This property is formatted as an octet string, structured " + "as follows:\n " + " o a 4-octet length field, indicating the length of the " + " entire octet string; this field is always set to " + " 0x00000005 for this property;\n" + " o a 1-octet field consisting of 7 bits identifying the 7 " + " days of the week, beginning with Sunday and ending with " + " Saturday, followed by 1 bit that is always set to '0'. " + " For each day of the week, the value '1' indicates that " + " the policy is valid for that day, and the value '0' " + " indicates that it is not valid. \n\n" + " " + "The value 0x000000057C, for example, indicates that a " + "PolicyRule is valid Monday through Friday.\n\n" + " " + "If a value for this property is not provided, then the " + "PolicyRule is treated as valid for all days of the week, " + "and only restricted by its TimePeriod property value and " + "the other Mask properties."), + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.TimePeriod", + "CIM_PolicyTimePeriodCondition.LocalOrUtcTime"} + ] + uint8 DayOfWeekMask[]; + [Description ( + " The purpose of this property is to refine the valid time " + + + +Moore, et al. Standards Track [Page 91] + +RFC 3060 Policy Core Information Model February 2001 + + + "period that is defined by the TimePeriod property, by " + "explicitly specifying a range of times in a day during which " + "the PolicyRule is valid. These properties work " + "together, with the TimePeriod used to specify the overall " + "time period in which the PolicyRule is valid, and the " + "TimeOfDayMask used to pick out the range of time periods " + "in a given day of during which the Rule is valid. \n\n" + " " + "This property is formatted in the style of RFC 2445: a " + "time string beginning with the character 'T', followed by " + "the solidus character '/', followed by a second time string. " + "The first time indicates the beginning of the range, while " + "the second time indicates the end. Times are expressed as " + "substrings of the form 'Thhmmss'. \n\n" + " " + "The second substring always identifies a later time than " + "the first substring. To allow for ranges that span " + "midnight, however, the value of the second string may be " + "smaller than the value of the first substring. Thus, " + "'T080000/T210000' identifies the range from 0800 until 2100, " + "while 'T210000/T080000' identifies the range from 2100 until " + "0800 of the following day. \n\n" + " " + "When a range spans midnight, it by definition includes " + "parts of two successive days. When one of these days is " + "also selected by either the MonthOfYearMask, " + "DayOfMonthMask, and/or DayOfWeekMask, but the other day is " + "not, then the policy is active only during the portion of " + "the range that falls on the selected day. For example, if " + "the range extends from 2100 until 0800, and the day of " + "week mask selects Monday and Tuesday, then the policy is " + "active during the following three intervals:\n" + " From midnight Sunday until 0800 Monday; \n" + " From 2100 Monday until 0800 Tuesday; \n" + " From 2100 Tuesday until 23:59:59 Tuesday. \n\n" + " " + "If a value for this property is not provided, then the " + "PolicyRule is treated as valid for all hours of the day, " + "and only restricted by its TimePeriod property value and " + "the other Mask properties."), + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.TimePeriod", + "CIM_PolicyTimePeriodCondition.LocalOrUtcTime"} + ] + string TimeOfDayMask; + [Description ( + " This property indicates whether the times represented " + "in the TimePeriod property and in the various Mask " + + + +Moore, et al. Standards Track [Page 92] + +RFC 3060 Policy Core Information Model February 2001 + + + "properties represent local times or UTC times. There is " + "no provision for mixing of local times and UTC times: the " + "value of this property applies to all of the other " + "time-related properties."), + ValueMap { "1", "2" }, + Values { "localTime", "utcTime" }, + ModelCorrespondence { + "CIM_PolicyTimePeriodCondition.TimePeriod", + "CIM_PolicyTimePeriodCondition.MonthOfYearMask", + "CIM_PolicyTimePeriodCondition.DayOfMonthMask", + "CIM_PolicyTimePeriodCondition.DayOfWeekMask", + "CIM_PolicyTimePeriodCondition.TimeOfDayMask"} + ] + uint16 LocalOrUtcTime; +}; + +// ================================================================== +// PolicyRuleValidityPeriod +// ================================================================== + [Association, Aggregation, Description ( + "The PolicyRuleValidityPeriod aggregation represents " + "scheduled activation and deactivation of a PolicyRule. " + "If a PolicyRule is associated with multiple policy time " + "periods via this association, then the Rule is active if " + "at least one of the time periods indicates that it is " + "active. (In other words, the PolicyTimePeriodConditions " + "are ORed to determine whether the Rule is active.) A Time" + "Period may be aggregated by multiple PolicyRules. A Rule " + "that does not point to a PolicyTimePeriodCondition via this " + "association is, from the point of view of scheduling, " + "always active. It may, however, be inactive for other " + "reasons. For example, the Rule's Enabled property may " + "be set to \"disabled\" (value=2).") + ] +class CIM_PolicyRuleValidityPeriod : CIM_PolicyComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "This property contains the name of a PolicyRule that " + "contains one or more PolicyTimePeriodConditions.") + ] + CIM_PolicyRule REF GroupComponent; + [Override ("PartComponent"), Description ( + "This property contains the name of a " + "PolicyTimePeriodCondition defining the valid time periods " + "for one or more PolicyRules.") + ] + CIM_PolicyTimePeriodCondition REF PartComponent; +}; + + + +Moore, et al. Standards Track [Page 93] + +RFC 3060 Policy Core Information Model February 2001 + + +// ================================================================== +// VendorPolicyCondition +// ================================================================== + [Description ( + " A class that provides a general extension mechanism for " + "representing PolicyConditions that have not been modeled " + "with specific properties. Instead, the two properties " + "Constraint and ConstraintEncoding are used to define the " + "content and format of the Condition, as explained below.\n\n" + " " + "As its name suggests, VendorPolicyCondition is intended for " + "vendor-specific extensions to the Policy Core Information " + "Model. Standardized extensions are not expected to use " + "this class.") + ] +class CIM_VendorPolicyCondition : CIM_PolicyCondition +{ + [Octetstring, Description ( + "This property provides a general extension mechanism for " + "representing PolicyConditions that have not been " + "modeled with specific properties. The format of the " + "octet strings in the array is left unspecified in " + "this definition. It is determined by the OID value " + "stored in the property ConstraintEncoding. Since " + "ConstraintEncoding is single-valued, all the values of " + "Constraint share the same format and semantics."), + ModelCorrespondence { + "CIM_VendorPolicyCondition.ConstraintEncoding"} + ] + string Constraint []; + [Description ( + "An OID encoded as a string, identifying the format " + "and semantics for this instance's Constraint property."), + ModelCorrespondence { + "CIM_VendorPolicyCondition.Constraint"} + ] + string ConstraintEncoding; +}; + +// ================================================================== +// PolicyAction +// ================================================================== + [Abstract, Description ( + "A class representing a rule-specific or reusable policy " + "action to be performed if the PolicyConditions for a Policy" + "Rule evaluate to TRUE. Since all operational details of a " + "PolicyAction are provided in subclasses of this object, " + "this class is abstract.") + + + +Moore, et al. Standards Track [Page 94] + +RFC 3060 Policy Core Information Model February 2001 + + + ] +class CIM_PolicyAction : CIM_Policy +{ + [Key, MaxLen (256), Description ( + " The name of the class or the subclass used in the " + "creation of the System object in whose scope this " + "PolicyAction is defined. \n\n" + " " + "This property helps to identify the System object in " + "whose scope this instance of PolicyAction exists. " + "For a rule-specific PolicyAction, this is the System " + "in whose context the PolicyRule is defined. For a " + "reusable PolicyAction, this is the instance of " + "PolicyRepository (which is a subclass of System) that " + "holds the Action. \n\n" + " " + "Note that this property, and the analogous property " + "SystemName, do not represent propagated keys from an " + "instance of the class System. Instead, they are " + "properties defined in the context of this class, which " + "repeat the values from the instance of System to which " + "this PolicyAction is related, either directly via the " + "PolicyActionInPolicyRepository aggregation or indirectly " + "via the PolicyActionInPolicyRule aggregation.") + ] + string SystemCreationClassName; + [Key, MaxLen (256), Description ( + " The name of the System object in whose scope this " + "PolicyAction is defined. \n\n" + " " + "This property completes the identification of the System " + "object in whose scope this instance of PolicyAction " + "exists. For a rule-specific PolicyAction, this is the " + "System in whose context the PolicyRule is defined. For " + "a reusable PolicyAction, this is the instance of " + "PolicyRepository (which is a subclass of System) that " + "holds the Action.") + ] + string SystemName; + [Key, MaxLen (256), Description ( + "For a rule-specific PolicyAction, the CreationClassName " + "of the PolicyRule object with which this Action is " + "associated. For a reusable PolicyAction, a " + "special value, 'NO RULE', should be used to " + "indicate that this Action is reusable and not " + "associated with a single PolicyRule.") + ] + string PolicyRuleCreationClassName; + + + +Moore, et al. Standards Track [Page 95] + +RFC 3060 Policy Core Information Model February 2001 + + + [Key, MaxLen (256), Description ( + "For a rule-specific PolicyAction, the name of " + "the PolicyRule object with which this Action is " + "associated. For a reusable PolicyAction, a " + "special value, 'NO RULE', should be used to " + "indicate that this Action is reusable and not " + "associated with a single PolicyRule.") + ] + string PolicyRuleName; + [Key, MaxLen (256), Description ( + "CreationClassName indicates the name of the class or the " + "subclass used in the creation of an instance. When used " + "with the other key properties of this class, this property " + "allows all instances of this class and its subclasses to " + "be uniquely identified.") ] + string CreationClassName; + [Key, MaxLen (256), Description ( + "A user-friendly name of this PolicyAction.") + ] + string PolicyActionName; +}; + +// ================================================================== +// PolicyActionInPolicyRepository +// ================================================================== + [Association, Description ( + " A class representing the hosting of reusable " + "PolicyActions by a PolicyRepository. A reusable Policy" + "Action is always related to a single PolicyRepository, " + "via this aggregation.\n\n" + " " + "Note, that an instance of PolicyAction can be either " + "reusable or rule-specific. When the Action is rule-" + "specific, it shall not be related to any " + "PolicyRepository via the PolicyActionInPolicyRepository " + "aggregation.") + ] +class CIM_PolicyActionInPolicyRepository : CIM_PolicyInSystem +{ + [Override ("Antecedent"), Max(1), Description ( + "This property represents a PolicyRepository " + "hosting one or more PolicyActions. A reusable " + "PolicyAction is always related to exactly one " + "PolicyRepository via the PolicyActionInPolicyRepository " + "aggregation. The [0..1] cardinality for this property " + "covers the two types of PolicyActions: 0 for a " + "rule-specific PolicyAction, 1 for a reusable one.") + ] + + + +Moore, et al. Standards Track [Page 96] + +RFC 3060 Policy Core Information Model February 2001 + + + CIM_PolicyRepository REF Antecedent; + [Override ("Dependent"), Description ( + "This property holds the name of a PolicyAction" + "hosted in the PolicyRepository. ") + ] + CIM_PolicyAction REF Dependent; +}; + +// ================================================================== +// PolicyActionInPolicyRule +// ================================================================== + [Association, Aggregation, Description ( + " A PolicyRule aggregates zero or more instances of the " + "PolicyAction class, via the PolicyActionInPolicyRule " + "association. A Rule that aggregates zero Actions is not " + "valid -- it may, however, be in the process of being entered " + "into a PolicyRepository or being defined for a System. " + "Alternately, the actions of the policy may be explicit in " + "the definition of the PolicyRule. Note that a PolicyRule " + "should have no effect until it is valid.\n\n" + " " + "The Actions associated with a PolicyRule may be given a " + "required order, a recommended order, or no order at all. For " + "Actions represented as separate objects, the PolicyActionIn" + "PolicyRule aggregation can be used to express an order. \n\n" + " " + "This aggregation does not indicate whether a specified " + "action order is required, recommended, or of no significance; " + "the property SequencedActions in the aggregating instance of " + "PolicyRule provides this indication.") + ] +class CIM_PolicyActionInPolicyRule : CIM_PolicyComponent +{ + [Override ("GroupComponent"), Aggregate, Description ( + "This property represents the PolicyRule that " + "contains one or more PolicyActions.") + ] + CIM_PolicyRule REF GroupComponent; + [Override ("PartComponent"), Description ( + "This property holds the name of a PolicyAction " + "contained by one or more PolicyRules.") + ] + CIM_PolicyAction REF PartComponent; + [Description ( + " This property provides an unsigned integer 'n' that" + "indicates the relative position of a PolicyAction in the " + "sequence of actions associated with a PolicyRule. " + "When 'n' is a positive integer, it indicates a place " + + + +Moore, et al. Standards Track [Page 97] + +RFC 3060 Policy Core Information Model February 2001 + + + "in the sequence of actions to be performed, with " + "smaller integers indicating earlier positions in the " + "sequence. The special value '0' indicates 'don't care'. " + "If two or more PolicyActions have the same non-zero " + "sequence number, they may be performed in any order, but " + "they must all be performed at the appropriate place in the " + "overall action sequence. \n\n" + " " + "A series of examples will make ordering of PolicyActions " + "clearer: \n" + " o If all actions have the same sequence number, " + " regardless of whether it is '0' or non-zero, any " + " order is acceptable.\n " + " o The values: \n" + " 1:ACTION A \n" + " 2:ACTION B \n" + " 1:ACTION C \n" + " 3:ACTION D \n" + " indicate two acceptable orders: A,C,B,D or C,A,B,D, " + " since A and C can be performed in either order, but " + " only at the '1' position. \n" + " o The values: \n" + " 0:ACTION A \n" + " 2:ACTION B \n" + " 3:ACTION C \n" + " 3:ACTION D \n" + " require that B,C, and D occur either as B,C,D or as " + " B,D,C. Action A may appear at any point relative to " + " B, C, and D. Thus the complete set of acceptable " + " orders is: A,B,C,D; B,A,C,D; B,C,A,D; B,C,D,A; " + " A,B,D,C; B,A,D,C; B,D,A,C; B,D,C,A. \n\n" + " " + "Note that the non-zero sequence numbers need not start " + "with '1', and they need not be consecutive. All that " + "matters is their relative magnitude.") + ] + uint16 ActionOrder; +}; + +// ================================================================== +// VendorPolicyAction +// ================================================================== + [Description ( + " A class that provides a general extension mechanism for " + "representing PolicyActions that have not been modeled " + "with specific properties. Instead, the two properties " + "ActionData and ActionEncoding are used to define the " + "content and format of the Action, as explained below.\n\n" + + + +Moore, et al. Standards Track [Page 98] + +RFC 3060 Policy Core Information Model February 2001 + + + " " + "As its name suggests, VendorPolicyAction is intended for " + "vendor-specific extensions to the Policy Core Information " + "Model. Standardized extensions are not expected to use " + "this class.") ] +class CIM_VendorPolicyAction : CIM_PolicyAction +{ + [Octetstring, Description ( + "This property provides a general extension mechanism for " + "representing PolicyActions that have not been " + "modeled with specific properties. The format of the " + "octet strings in the array is left unspecified in " + "this definition. It is determined by the OID value " + "stored in the property ActionEncoding. Since " + "ActionEncoding is single-valued, all the values of " + "ActionData share the same format and semantics."), + ModelCorrespondence { + "CIM_VendorPolicyAction.ActionEncoding"} + ] + string ActionData []; + [Description ( + "An OID encoded as a string, identifying the format " + "and semantics for this instance's ActionData property."), + ModelCorrespondence { + "CIM_VendorPolicyAction.ActionData"} + ] + string ActionEncoding; +}; + +// =================================================================== +// end of file +// =================================================================== + + + + + + + + + + + + + + + + + + + +Moore, et al. Standards Track [Page 99] + +RFC 3060 Policy Core Information Model February 2001 + + +15. Full Copyright Statement + + Copyright (C) The Internet Society (2001). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + + + + + + + + + + + + + +Moore, et al. Standards Track [Page 100] + |