--- xxx.old Wed Oct 29 17:23:48 2003 +++ xxx.new Wed Oct 29 17:23:48 2003 @@ -1,2572 +1,2589 @@ Network Working Group F. Strauss Internet-Draft TU Braunschweig -Expires: March 19, 2004 J. Schoenwaelder +Expires: April 28, 2004 J. Schoenwaelder International University Bremen - September 19, 2003 + October 29, 2003 SMIng - Next Generation Structure of Management Information - draft-irtf-nmrg-sming-05 + draft-irtf-nmrg-sming-06 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on March 19, 2004. + This Internet-Draft will expire on April 28, 2004. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract - This memo presents a data definition language for the specification - of various kinds of management information. It is independent of - management protocols and applications. Protocol mappings are defined - as extensions to this language in separate memos. The language - builds on experiences gained with the SMIv2 and its derivate SPPI. + This memo defines the base SMIng (Structure of Management + Information, Next Generation) language. SMIng is a data definition + language that provides a protocol-independent representation for + management information. A companion document [RFCxxx2] defines a + core module that supplies common SMIng definitions. Separate RFCs + define mappings of SMIng to specific management protocols, including + SNMP [RFCxxx3]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 The History of SMIng . . . . . . . . . . . . . . . . . . . . 5 1.2 Terms of Requirement Levels . . . . . . . . . . . . . . . . 5 2. SMIng Data Modelling . . . . . . . . . . . . . . . . . . . . 5 - 2.1 Identifiers . . . . . . . . . . . . . . . . . . . . . . . . 6 + 2.1 Identifiers . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Base Types and Derived Types . . . . . . . . . . . . . . . . 8 3.1 OctetString . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2 Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 3.3 Object Identifier . . . . . . . . . . . . . . . . . . . . . 10 + 3.3 ObjectIdentifier . . . . . . . . . . . . . . . . . . . . . . 10 3.4 Integer32 . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 3.5 Integer64 . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 3.6 Unsigned32 . . . . . . . . . . . . . . . . . . . . . . . . . 12 + 3.5 Integer64 . . . . . . . . . . . . . . . . . . . . . . . . . 12 + 3.6 Unsigned32 . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.7 Unsigned64 . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.8 Float32 . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.9 Float64 . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.10 Float128 . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.11 Enumeration . . . . . . . . . . . . . . . . . . . . . . . . 17 3.12 Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.13 Display Formats . . . . . . . . . . . . . . . . . . . . . . 19 4. The SMIng File Structure . . . . . . . . . . . . . . . . . . 21 4.1 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2 Textual Data . . . . . . . . . . . . . . . . . . . . . . . . 21 4.3 Statements and Arguments . . . . . . . . . . . . . . . . . . 22 5. The module Statement . . . . . . . . . . . . . . . . . . . . 22 5.1 The module's import Statement . . . . . . . . . . . . . . . 23 5.2 The module's organization Statement . . . . . . . . . . . . 24 5.3 The module's contact Statement . . . . . . . . . . . . . . . 24 5.4 The module's description Statement . . . . . . . . . . . . . 24 5.5 The module's reference Statement . . . . . . . . . . . . . . 24 5.6 The module's revision Statement . . . . . . . . . . . . . . 24 5.6.1 The revision's date Statement . . . . . . . . . . . . . . . 24 5.6.2 The revision's description Statement . . . . . . . . . . . . 25 5.7 Usage Example . . . . . . . . . . . . . . . . . . . . . . . 25 6. The extension Statement . . . . . . . . . . . . . . . . . . 26 - 6.1 The extension's status Statement . . . . . . . . . . . . . . 26 - 6.2 The extension's description Statement . . . . . . . . . . . 26 - 6.3 The extension's reference Statement . . . . . . . . . . . . 26 + 6.1 The extension's status Statement . . . . . . . . . . . . . . 27 + 6.2 The extension's description Statement . . . . . . . . . . . 27 + 6.3 The extension's reference Statement . . . . . . . . . . . . 27 6.4 The extension's abnf Statement . . . . . . . . . . . . . . . 27 - 6.5 Usage Example . . . . . . . . . . . . . . . . . . . . . . . 27 - 7. The typedef Statement . . . . . . . . . . . . . . . . . . . 27 - 7.1 The typedef's type Statement . . . . . . . . . . . . . . . . 27 + 6.5 Usage Example . . . . . . . . . . . . . . . . . . . . . . . 28 + 7. The typedef Statement . . . . . . . . . . . . . . . . . . . 28 + 7.1 The typedef's type Statement . . . . . . . . . . . . . . . . 28 7.2 The typedef's default Statement . . . . . . . . . . . . . . 28 - 7.3 The typedef's format Statement . . . . . . . . . . . . . . . 28 - 7.4 The typedef's units Statement . . . . . . . . . . . . . . . 28 + 7.3 The typedef's format Statement . . . . . . . . . . . . . . . 29 + 7.4 The typedef's units Statement . . . . . . . . . . . . . . . 29 7.5 The typedef's status Statement . . . . . . . . . . . . . . . 29 - 7.6 The typedef's description Statement . . . . . . . . . . . . 29 + 7.6 The typedef's description Statement . . . . . . . . . . . . 30 - 7.7 The typedef's reference Statement . . . . . . . . . . . . . 29 + 7.7 The typedef's reference Statement . . . . . . . . . . . . . 30 7.8 Usage Examples . . . . . . . . . . . . . . . . . . . . . . . 30 - 8. The identity Statement . . . . . . . . . . . . . . . . . . . 30 + 8. The identity Statement . . . . . . . . . . . . . . . . . . . 31 8.1 The identity's parent Statement . . . . . . . . . . . . . . 31 - 8.2 The identity's status Statement . . . . . . . . . . . . . . 31 - 8.3 The identity' description Statement . . . . . . . . . . . . 31 - 8.4 The identity's reference Statement . . . . . . . . . . . . . 31 - 8.5 Usage Examples . . . . . . . . . . . . . . . . . . . . . . . 32 - 9. The class Statement . . . . . . . . . . . . . . . . . . . . 32 - 9.1 The class' extends Statement . . . . . . . . . . . . . . . . 32 + 8.2 The identity's status Statement . . . . . . . . . . . . . . 32 + 8.3 The identity' description Statement . . . . . . . . . . . . 32 + 8.4 The identity's reference Statement . . . . . . . . . . . . . 32 + 8.5 Usage Examples . . . . . . . . . . . . . . . . . . . . . . . 33 + 9. The class Statement . . . . . . . . . . . . . . . . . . . . 33 + 9.1 The class' extends Statement . . . . . . . . . . . . . . . . 33 9.2 The class' attribute Statement . . . . . . . . . . . . . . . 33 - 9.2.1 The attribute's type Statement . . . . . . . . . . . . . . . 33 - 9.2.2 The attribute's access Statement . . . . . . . . . . . . . . 33 - 9.2.3 The attribute's default Statement . . . . . . . . . . . . . 33 + 9.2.1 The attribute's type Statement . . . . . . . . . . . . . . . 34 + 9.2.2 The attribute's access Statement . . . . . . . . . . . . . . 34 + 9.2.3 The attribute's default Statement . . . . . . . . . . . . . 34 9.2.4 The attribute's format Statement . . . . . . . . . . . . . . 34 - 9.2.5 The attribute's units Statement . . . . . . . . . . . . . . 34 - 9.2.6 The attribute's status Statement . . . . . . . . . . . . . . 34 - 9.2.7 The attribute's description Statement . . . . . . . . . . . 35 - 9.2.8 The attribute's reference Statement . . . . . . . . . . . . 35 - 9.3 The class' unique Statement . . . . . . . . . . . . . . . . 35 - 9.4 The class' event Statement . . . . . . . . . . . . . . . . . 35 - 9.4.1 The event's status Statement . . . . . . . . . . . . . . . . 36 - 9.4.2 The event's description Statement . . . . . . . . . . . . . 36 - 9.4.3 The event's reference Statement . . . . . . . . . . . . . . 36 - 9.5 The class' status Statement . . . . . . . . . . . . . . . . 36 - 9.6 The class' description Statement . . . . . . . . . . . . . . 37 - 9.7 The class's reference Statement . . . . . . . . . . . . . . 37 - 9.8 Usage Example . . . . . . . . . . . . . . . . . . . . . . . 37 - 10. Extending a Module . . . . . . . . . . . . . . . . . . . . . 38 - 11. SMIng Language Extensibility . . . . . . . . . . . . . . . . 40 - 12. Security Considerations . . . . . . . . . . . . . . . . . . 41 - 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 41 - Normative References . . . . . . . . . . . . . . . . . . . . 42 - Informative References . . . . . . . . . . . . . . . . . . . 42 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 43 - A. SMIng ABNF Grammar . . . . . . . . . . . . . . . . . . . . . 44 - Intellectual Property and Copyright Statements . . . . . . . 54 + 9.2.5 The attribute's units Statement . . . . . . . . . . . . . . 35 + 9.2.6 The attribute's status Statement . . . . . . . . . . . . . . 35 + 9.2.7 The attribute's description Statement . . . . . . . . . . . 36 + 9.2.8 The attribute's reference Statement . . . . . . . . . . . . 36 + 9.3 The class' unique Statement . . . . . . . . . . . . . . . . 36 + 9.4 The class' event Statement . . . . . . . . . . . . . . . . . 36 + 9.4.1 The event's status Statement . . . . . . . . . . . . . . . . 37 + 9.4.2 The event's description Statement . . . . . . . . . . . . . 37 + 9.4.3 The event's reference Statement . . . . . . . . . . . . . . 37 + 9.5 The class' status Statement . . . . . . . . . . . . . . . . 37 + 9.6 The class' description Statement . . . . . . . . . . . . . . 38 + 9.7 The class's reference Statement . . . . . . . . . . . . . . 38 + 9.8 Usage Example . . . . . . . . . . . . . . . . . . . . . . . 38 + 10. Extending a Module . . . . . . . . . . . . . . . . . . . . . 39 + 11. SMIng Language Extensibility . . . . . . . . . . . . . . . . 41 + 12. Security Considerations . . . . . . . . . . . . . . . . . . 42 + 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 42 + Normative References . . . . . . . . . . . . . . . . . . . . 43 + Informative References . . . . . . . . . . . . . . . . . . . 43 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 44 + A. SMIng ABNF Grammar . . . . . . . . . . . . . . . . . . . . . 45 + Intellectual Property and Copyright Statements . . . . . . . 55 1. Introduction In traditional management systems management information is viewed as a collection of managed objects, residing in a virtual information store, termed the Management Information Base (MIB). Collections of related objects are defined in MIB modules. These modules are written conforming to a specification language, the Structure of Management Information (SMI). There are different versions of the SMI. The SMI version 1 (SMIv1) is defined in [RFC1155], [RFC1212], [RFC1215] and the SMI version 2 (SMIv2) in [RFC2578], [RFC2579], [RFC2580]. Both are based on adapted subsets of OSI's Abstract Syntax Notation One, ASN.1 [ASN1]. In a similar fashion policy provisioning information is viewed as a collection of Provisioning Classes (PRCs) and Provisioning Instances (PRIs) residing in a virtual information store, termed the Policy Information Base (PIB). Collections of related Provisioning Classes are defined in PIB modules. PIB modules are written using the Structure of Policy Provisioning Information (SPPI) [RFC3159] which is an adapted subset of SMIv2. The SMIv1 and the SMIv2 are bound to the Simple Network Management Protocol (SNMP) while the the SPPI is bound to the Common Open Policy Service Provisioning (COPS-PR) protocol. Even though the languages have common rules, it is hard to use common data definitions with both protocols. It is the purpose of this document to define a common data definition language, named SMIng, that allows to formally specify data models independent of specific protocols and applications. Companion documents contain - o core modules that supply common SMIng definitions [Modules], + o core modules that supply common SMIng definitions [RFCxxx2], o an SMIng language extension to define SNMP specific mappings of - SMIng definitions in a way compatible to SMIv2 MIBs [SNMP], and + SMIng definitions in a way compatible to SMIv2 MIBs [RFCxxx3]. Additional language extensions may be added in the future, e.g. to define COPS-PR specific mappings of SMIng definition in a way compatible to SPPI PIBs. Section 2 gives an overview of the basic concepts of data modelling using SMIng while the subsequent sections present the concepts of the SMIng language in detail: the base types, the SMIng file structure, and all SMIng core statements. The remainder of the document describes extensibility features of the language and rules to follow when changes are applied to a module. Appendix A contains the grammar of SMIng in ABNF [RFC2234] notation. 1.1 The History of SMIng SMIng started in 1999 as a research project to address some drawbacks of SMIv2, the current data modelling language for management information bases, primarily its partial dependence on ASN.1 and a - number of exceptional rules that turned out to be problematic. In + number of exception rules that turned out to be problematic. In 2000, the work was handed over to the IRTF Network Management Research Group where it was significantly detailed. Since the work of the RAP Working Group on COPS-PR and SPPI emerged in 1999/2000, SMIng was split into two parts: a core data definition language (defined in this document) and protocol mappings to allow the application of core defintions through (potentially) multiple management protocols. The replacement of SMIv2 and SPPI by a single merged data definition language was also a primary goal of the IETF SMING Working Group that was chartered at the end of 2000. The requirements for a new data definition language were discussed several times within the IETF SMING Working Group and changed - significantly over time [RFC3216], so that another proposal, named - SMI Data Structures (SMI-DS) was presented to the Working Group. In - the end none of the two proposals found enough consensus and support - and the attempt to merge the existing concepts did not succeed, so - that the Working Group was closed down in April 2003. - - In order to record the NMRG work on SMIng, this memo and the - accompanying memos on the SNMP protocol mapping [SNMP] and on core - SMIng modules [Modules] have been published for informational - purpose. - - Note that throughout these three documents the term "SMIng" refers to - the specific data modelling language that is specified in this - document, whereas the term "SMING" refers to the general effort - within the IETF Working Group to define a new management data - definition language as an SMIv2 successor and probably an SPPI - merger, for which "SMIng" and "SMI-DS" were two specific proposals. + significantly over time [RFC3216], so that another proposal (in + addition to SMIng), named SMI Data Structures (SMI-DS) was presented + to the Working Group. In the end neither of the two proposals found + enough consensus and support and the attempt to merge the existing + concepts did not succeed, so that the Working Group was closed down + in April 2003. + + In order to record the work of the NMRG (Network Management Research + Group) on SMIng, this memo and the accompanying memos on the SNMP + protocol mapping [RFCxxx3] and on core SMIng modules [RFCxxx2] have + been published for informational purpose. + + Note that throughout the present document and its two companions + [RFCxxx3], [RFCxxx2] the term "SMIng" refers to the specific data + modelling language that is specified in this document, whereas the + term "SMING" refers to the general effort within the IETF Working + Group to define a new management data definition language as an SMIv2 + successor and probably an SPPI merger, for which "SMIng" and "SMI-DS" + were two specific proposals. 1.2 Terms of Requirement Levels 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 [RFC2119]. 2. SMIng Data Modelling SMIng is a language designed to specify management information in a structured way readable to computer programs, e.g. MIB compilers, as + well as to human readers. Management information is modeled in classes. Classes can be defined from scratch or by derivation from a parent class. Derivation from multiple parent classes is not possible. The concept of classes is described in Section 9. Each class has a number of attributes. Each attribute represents an atomic piece of information of a base type, a sub-type of a base type, or another class. The concept of attributes is described in Section 9.2. The base types of SMIng include signed and unsigned integers, octet strings, enumeration types, bitset types, and pointers. Pointers are references to class instances, attributes of class instances, or arbitrary identities. The SMIng type system is described in Section 3. Related class and type definitions are defined in modules. A module may refer to definitions from other modules by importing identifiers from those modules. Each module may serve one or multiple purposes: o the definition of management classes, o the definition of events, o the definition of derived types, o the definition of arbitrary untyped identities serving as values of pointers, o the definition of SMIng extensions to allow the local module or other modules to specify information beyond the scope of the base SMIng in a machine readable notation. Some extensions for the - application of SMIng in the SNMP framework are defined in [SNMP], + application of SMIng in the SNMP framework are defined in + [RFCxxx3], o the definition of information beyond the scope of the base SMIng statements, based on locally defined or imported SMIng extensions. Each module is identified by an upper-case identifier. The names of all standard modules must be unique (but different versions of the same module should have the same name). Developers of enterprise modules are encouraged to choose names for their modules that will have a low probability of colliding with standard or other enterprise modules, e.g. by using the enterprise or organization name as a prefix. 2.1 Identifiers Identifiers are used to identify different kinds of SMIng items by - name. Each identifier is valid in a namespace which depends on the type of the SMIng item being defined: o The global namespace contains all module identifiers. o Each module defines a new namespace. A module's namespace may contain definitions of extension identifiers, derived type identifiers, identity identifiers, and class identifiers. Furthermore, a module may import identifiers of these kinds from other modules. All these identifiers are also visible within all inner namespaces of the module. o Each class within a module defines a new namespace. A class' namespace may contain definitions of attribute identifiers and event identifiers. o Each enumeration type and bitset type defines a new namespace of its named numbers. These named numbers are visible in each expression of a corresponding value, e.g., default values and sub-typing restrictions. o Extensions may define additional namespaces and have additional rules of other namespaces' visibilty. Within every namespace each identifier MUST be unique. Each identifier starts with an upper-case or lower-case character, dependent on the kind of SMIng item, followed by zero or more letters, digits and hyphens. All identifiers defined in a namespace MUST be unique and SHOULD NOT only differ in case. Identifiers MUST NOT exceed 64 characters in length. Furthermore, the set of all identifiers defined in all modules of a single standardization body or organization SHOULD be unique and mnemonic. This promotes a common language for humans to use when discussing a module. To reference an item that is defined in the local module, its definition MUST sequentially precede the reference. Thus, there MUST NOT be any forward references. To reference an item, that is defined in an external module it MUST be imported (Section 5.1). Identifiers that are neither defined nor imported MUST NOT be visible in the local module. When identifiers from external modules are referenced, there is the possibility of name collisions. As such, if different items with the same identifier are imported or if imported identifiers collide with - identifiers of locally defined items, then this ambiguity is resolved by prefixing those identifiers with the names of their modules and the namespace operator `::', i.e. `Module::item'. Of course, this notation can be used to refer to identifiers even when there is no name collision. Note that SMIng core language keywords MUST NOT be imported. See the `...Keyword' rules of the SMIng ABNF grammar in Appendix A for a list of those keywords. 3. Base Types and Derived Types SMIng has a set of base types, similar to those of many programming languages, but with some differences due to special requirements from the management information model. Additional types may be defined, derived from those base types or from other derived types. Derived types may use subtyping to formally restrict the set of possible values. An initial set of commonly used derived types is defined in the SMIng standard module - NMRG-SMING [Modules]. + NMRG-SMING [RFCxxx2]. The different base types and their derived types allow different kinds of subtyping, namely size restrictions of octet strings (Section 3.1), range restrictions of numeric types (Section 3.4 through Section 3.10), restricted pointer types (Section 3.2), and restrictions of the sets of named numbers for enumeration types (Section 3.11) and bit sets (Section 3.12). 3.1 OctetString The OctetString base type represents arbitrary binary or textual data. Although SMIng has a theoretical size limitation of 2^16-1 (65535) octets for this base type, module designers should realize that there may be implementation and interoperability limitations for sizes in excess of 255 octets. Values of octet strings may be denoted as textual data enclosed in double quotes or as arbitrary binary data denoted as a `0x'-prefixed hexadecimal value of an even number of at least two hexadecimal digits, where each pair of hexadecimal digits represents a single octet. Letters in hexadecimal values MAY be upper-case but lower-case characters are RECOMMENDED. Textual data may contain any number (possibly zero) of any 7-bit displayable ASCII characters, including tab characters, spaces and line terminator characters (nl + or cr & nl). Some characters require a special encoding (see Section 4.2). Textual data may span multiple lines, where each subsequent line prefix containing only white space up to the column where the - first line's data starts SHOULD be skipped by parsers for a better text formatting. When defining a type derived (directly or indirectly) from the OctetString base type, the size in octets may be restricted by appending a list of size ranges or explicit size values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A size range consists of a lower bound, two consecutive dots `..' and an upper bound. Each value can be given in decimal or `0x'-prefixed hexadecimal notation. Hexadecimal numbers must have an even number of at least two digits. Size restricting values MUST NOT be negative. If multiple values or ranges are given, they all MUST be disjoint and MUST be in ascending order. If a size restriction is applied to an already size restricted octet string the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit size values or ranges, or splitting ranges into multiple ranges with intermediate gaps. Value Examples: "This is a multiline textual data example." // legal "This is "illegally" quoted." // illegal quotes "This is \"legally\" quoted." // legally encoded quotes "But this is 'ok', as well." // legal apostrophe quoting "" // legal zero length 0x123 // illegal odd hex length 0x534d496e670a // legal octet string Restriction Examples: OctetString (0 | 4..255) // legal size spec OctetString (4) // legal exact size OctetString (-1 | 1) // illegal negative size OctetString (5 | 0) // illegal ordering OctetString (1 | 1..10) // illegal overlapping 3.2 Pointer The Pointer base type represents values that reference class instances, attributes of class instances, or arbitrary identities. The only values of the Pointer type that can be present in a module can refer to identities. They are denoted as identifiers of the + concerned identities. When defining a type derived (directly or indirectly) from the - Pointer base type, the values may be restricted to a specific class, attribute or identity and all (directly or indirectly) derived items thereof by appending the identifier of the appropriate construct enclosed in parenthesis. Value Examples: null // legal identity name snmpUDPDomain // legal identity name Restriction Examples: Pointer (snmpTransportDomain) // legal restriction -3.3 Object Identifier +3.3 ObjectIdentifier The ObjectIdentifier base type represents administratively assigned names for use with SNMP and COPS-PR. This type SHOULD NOT be used in protocol independant SMIng modules. It is meant to be used in SNMP and COPS-PR mappings of attributes of type Pointer (Section 3.2). Values of this type may be denoted as a sequence of numerical non-negative sub-identifier values which each MUST NOT exceed 2^32-1 (4294967295). Sub-identifiers may be denoted decimal or `0x'-prefixed hexadecimal. They are separated by single dots and without any intermediate white space. Alternatively (and preferred in most cases), the first element may be a previously defined or imported lower-case identifier, representing a static object identifier prefix. Although the number of sub-identifiers in SMIng object identifiers is not limited, module designers should realize that there may be implementations that stick with the SMIv1/v2 limit of 128 sub-identifiers. Object identifier derived types cannot be restricted in any way. Value Examples: 1.3.6.1 // legal numerical oid mib-2.1 // legal oid with identifier prefix internet.4.1.0x0627.0x01 // legal oid with hex subids iso.-1 // illegal negative subid iso.org.6 // illegal non-heading identifier IF-MIB::ifNumber.0 // legel fully quallified instance oid 3.4 Integer32 The Integer32 base type represents integer values between -2^31 (-2147483648) and 2^31-1 (2147483647). Values of type Integer32 may be denoted as decimal or hexadecimal numbers, where only decimal numbers can be negative. Decimal numbers other than zero MUST NOT have leading zero digits. Hexadecimal numbers are prefixed by `0x' and MUST have an even number of at least two hexadecimal digits, where letters MAY be upper-case but lower-case characters are RECOMMENDED. When defining a type derived (directly or indirectly) from the Integer32 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. Each value can be given in decimal or `0x'-prefixed hexadecimal notation. Hexadecimal numbers must have an even number of at least two digits. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. Value Examples: 015 // illegal leading zero -123 // legal negative value - 1 // illegal intermediate space 0xabc // illegal hexadecimal value length -0xff // illegal sign on hex value 0x80000000 // illegal value, too large 0xf00f // legal hexadecimal value Restriction Examples: Integer32 (0 | 5..10) // legal range spec Integer32 (5..10 | 2..3) // illegal ordering Integer32 (4..8 | 5..10) // illegal overlapping 3.5 Integer64 The Integer64 base type represents integer values between -2^63 (-9223372036854775808) and 2^63-1 (9223372036854775807). Values of type Integer64 may be denoted as decimal or hexadecimal numbers, where only decimal numbers can be negative. Decimal numbers other than zero MUST NOT have leading zero digits. Hexadecimal numbers are prefixed by `0x' and MUST have an even number of hexadecimal digits, where letters MAY be upper-case but lower-case characters are RECOMMENDED. When defining a type derived (directly or indirectly) from the Integer64 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. Each value can be given in decimal or `0x'-prefixed hexadecimal notation. Hexadecimal numbers must have an even number of at least two digits. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. Value Examples: 015 // illegal leading zero -123 // legal negative value - 1 // illegal intermediate space 0xabc // illegal hexadecimal value length -0xff // illegal sign on hex value 0x80000000 // legal value Restriction Examples: Integer64 (0 | 5..10) // legal range spec Integer64 (5..10 | 2..3) // illegal ordering Integer64 (4..8 | 5..10) // illegal overlapping 3.6 Unsigned32 The Unsigned32 base type represents positive integer values between 0 and 2^32-1 (4294967295). Values of type Unsigned32 may be denoted as decimal or hexadecimal numbers. Decimal numbers other than zero MUST NOT have leading zero digits. Hexadecimal numbers are prefixed by `0x' and MUST have an even number of hexadecimal digits, where letters MAY be upper-case but lower-case characters are RECOMMENDED. When defining a type derived (directly or indirectly) from the Unsigned32 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. Each value can be given in decimal or `0x'-prefixed hexadecimal notation. Hexadecimal numbers must have an even number of at least two digits. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. Value Examples: 015 // illegal leading zero -123 // illegal negative value 0xabc // illegal hexadecimal value length 0x80000000 // legal hexadecimal value 0x8080000000 // illegal value, too large Restriction Examples: Unsigned32 (0 | 5..10) // legal range spec Unsigned32 (5..10 | 2..3) // illegal ordering Unsigned32 (4..8 | 5..10) // illegal overlapping 3.7 Unsigned64 The Unsigned64 base type represents positive integer values between 0 and 2^64-1 (18446744073709551615). Values of type Unsigned64 may be denoted as decimal or hexadecimal numbers. Decimal numbers other than zero MUST NOT have leading zero + digits. Hexadecimal numbers are prefixed by `0x' and MUST have an even number of hexadecimal digits, where letters MAY be upper-case but lower-case characters are RECOMMENDED. When defining a type derived (directly or indirectly) from the Unsigned64 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. Each value can be given in decimal or `0x'-prefixed hexadecimal notation. Hexadecimal numbers must have an even number - of at least two digits. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. Value Examples: 015 // illegal leading zero -123 // illegal negative value 0xabc // illegal hexadecimal value length 0x8080000000 // legal hexadecimal value Restriction Examples: Unsigned64 (1..10000000000) // legal range spec Unsigned64 (5..10 | 2..3) // illegal ordering 3.8 Float32 The Float32 base type represents floating point values of single precision as described by [IEEE754]. Values of type Float32 may be denoted as a decimal fraction with an optional exponent as known from many programming languages. See the grammar rule `floatValue' of Appendix A for the detailed syntax. Special values are `snan' (signaling Not-a-Number), `qnan' (quiet Not-a-Number), `neginf' (negative infinity), and `posinf' (positive infinity). Note that -0.0 and +0.0 are different floating point values. 0.0 is equal to +0.0. When defining a type derived (directly or indirectly) from the Float32 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' + characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. The special values `snan', `qnan', `neginf', and `posinf' must be explicitly listed in restrictions if they shall be included, where `snan' and `qnan' cannot be used in ranges. Note that encoding is not subject to this specification. It has to be described by protocols that transport objects of type Float32. Note also that most floating point encodings disallow the representation of many values that can be written as decimal fractions as used in SMIng for human readability. Therefore, explicit values in floating point type restrictions should be handled with care. Value Examples: 00.1 // illegal leading zero 3.1415 // legal value -2.5E+3 // legal negative exponential value Restriction Examples: Float32 (-1.0..1.0) // legal range spec Float32 (1 | 3.3 | 5) // legal, probably unrepresentable 3.3 Float32 (neginf..-0.0) // legal range spec Float32 (-10.0..10.0 | 0) // illegal overlapping 3.9 Float64 The Float64 base type represents floating point values of double precision as described by [IEEE754]. Values of type Float64 may be denoted as a decimal fraction with an optional exponent as known from many programming languages. See the grammar rule `floatValue' of Appendix A for the detailed syntax. Special values are `snan' (signaling Not-a-Number), `qnan' (quiet Not-a-Number), `neginf' (negative infinity), and `posinf' (positive infinity). Note that -0.0 and +0.0 are different floating point values. 0.0 is equal to +0.0. When defining a type derived (directly or indirectly) from the + Float64 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. The special values `snan', `qnan', `neginf', and `posinf' must be explicitly listed in restrictions if they shall be included, where `snan' and - `qnan' cannot be used in ranges. Note that encoding is not subject to this specification. It has to be described by protocols that transport objects of type Float64. Note also that most floating point encodings disallow the representation of many values that can be written as decimal fractions as used in SMIng for human readability. Therefore, explicit values in floating point type restrictions should be handled with care. Value Examples: 00.1 // illegal leading zero 3.1415 // legal value -2.5E+3 // legal negative exponential value Restriction Examples: Float64 (-1.0..1.0) // legal range spec Float64 (1 | 3.3 | 5) // legal, probably unrepresentable 3.3 Float64 (neginf..-0.0) // legal range spec Float64 (-10.0..10.0 | 0) // illegal overlapping 3.10 Float128 The Float128 base type represents floating point values of quadruple precision as described by [IEEE754]. Values of type Float128 may be denoted as a decimal fraction with an optional exponent as known from many programming languages. See the grammar rule `floatValue' of Appendix A for the detailed syntax. Special values are `snan' (signaling Not-a-Number), `qnan' (quiet Not-a-Number), `neginf' (negative infinity), and `posinf' (positive infinity). Note that -0.0 and +0.0 are different floating point values. 0.0 is equal to +0.0. When defining a type derived (directly or indirectly) from the Float128 base type, the set of possible values may be restricted by appending a list of ranges or explicit values, separated by pipe `|' characters and the whole list enclosed in parenthesis. A range consists of a lower bound, two consecutive dots `..' and an upper bound. If multiple values or ranges are given they all MUST be disjoint and MUST be in ascending order. If a value restriction is applied to an already restricted type the new restriction MUST be equal or more limiting, that is raising the lower bounds, reducing the upper bounds, removing explicit values or ranges, or splitting ranges into multiple ranges with intermediate gaps. The special - values `snan', `qnan', `neginf', and `posinf' must be explicitly listed in restrictions if they shall be included, where `snan' and `qnan' cannot be used in ranges. Note that encoding is not subject to this specification. It has to be described by protocols that transport objects of type Float128. Note also that most floating point encodings disallow the representation of many values that can be written as decimal fractions as used in SMIng for human readability. Therefore, explicit values in floating point type restrictions should be handled with care. Value Examples: 00.1 // illegal leading zero 3.1415 // legal value -2.5E+3 // legal negative exponential value Restriction Examples: Float128 (-1.0..1.0) // legal range spec Float128 (1 | 3.3 | 5) // legal, probably unrepresentable 3.3 Float128 (neginf..-0.0) // legal range spec Float128 (-10.0..10.0 | 0) // illegal overlapping 3.11 Enumeration The Enumeration base type represents values from a set of integers in the range between -2^31 (-2147483648) and 2^31-1 (2147483647), where each value has an assigned name. The list of those named numbers has to be comma-separated, enclosed in parenthesis and appended to the `Enumeration' keyword. Each named number is denoted by its lower-case identifier followed by the assigned integer value, denoted as a decimal or `0x'-prefixed hexadecimal number, enclosed in parenthesis. Hexadecimal numbers must have an even number of at least two digits. Every name and every number in an enumeration type + MUST be unique. It is RECOMMENDED that values are positive and start at 1 and be numbered contiguously. All named numbers MUST be given in ascending order. Values of enumeration types may be denoted as decimal or `0x'-prefixed hexadecimal numbers or preferably as their assigned names. Hexadecimal numbers must have an even number of at least two digits. When types are derived (directly or indirectly) from an enumeration type, the set of named numbers may be equal or restricted by removing - one or more named numbers. But no named numbers may be added or changed regarding its name, value, or both. Type and Value Examples: Enumeration (up(1), down(2), testing(3)) Enumeration (down(2), up(1)) // illegal order 0 // legal (though not recommended) value up // legal value given by name 2 // legal value given by number 3.12 Bits The Bits base type represents bit sets. That is, a Bits value is a set of flags identified by small integer numbers starting at 0. Each bit number has an assigned name. The list of those named numbers has to be comma-separated, enclosed in parenthesis and appended to the `Bits' keyword. Each named number is denoted by its lower-case identifier followed by the assigned integer value, denoted as a decimal or `0x'-prefixed hexadecimal number, enclosed in parenthesis. Hexadecimal numbers must have an even number of at least two digits. Every name and every number in a bits type MUST be unique. It is RECOMMENDED that numbers start at 0 and be numbered contiguously. Negative numbers are forbidden. All named numbers MUST be given in ascending order. Values of bits types may be denoted as a comma-separated list of decimal or `0x'-prefixed hexadecimal numbers or preferably their assigned names enclosed in parenthesis. Hexadecimal numbers must have an even number of at least two digits. There MUST NOT be any element (by name or number) listed more than once. Elements MUST be listed in ascending order. When defining a type derived (directly or indirectly) from a bits type, the set of named numbers may be restricted by removing one or + more named numbers. But no named numbers may be added or changed regarding its name, value, or both. Type and Value Examples: Bits (readable(0), writeable(1), executable(2)) Bits (writeable(1), readable(0) // illegal order () // legal empty value (readable, writeable, 2) // legal value (0, readable, executable) // illegal, readable(0) appears twice - (writeable, 4) // illegal, element 4 out of range 3.13 Display Formats Attribute definitions and type definitions allow the specification of a format to be used, when a value of that attribute or an attribute of that type is displayed. Format specifications are represented as textual data. When the attribute or type has an underlying base type of Integer32, Integer64, Unsigned32, or Unsigned64, the format consists of an integer-format specification, containing two parts. The first part is a single character suggesting a display format, either: `x' for hexadecimal, or `d' for decimal, or `o' for octal, or `b' for binary. For all types, when rendering the value, leading zeros are omitted, and for negative values, a minus sign is rendered immediately before the digits. The second part is always omitted for `x', `o' and `b', and need not be present for `d'. If present, the second part starts with a hyphen and is followed by a decimal number, which defines the implied decimal point when rendering the value. For example `d-2' suggests that a value of 1234 be rendered as `12.34'. When the attribute or type has an underlying base type of OctetString, the format consists of one or more octet-format specifications. Each specification consists of five parts, with each part using and removing zero or more of the next octets from the value and producing the next zero or more characters to be displayed. The octets within the value are processed in order of significance, most significant first. The five parts of a octet-format specification are: 1. the (optional) repeat indicator; if present, this part is a `*', and indicates that the current octet of the value is to be used as the repeat count. The repeat count is an unsigned integer (which may be zero) which specifies how many times the remainder + of this octet-format specification should be successively applied. If the repeat indicator is not present, the repeat count is one. 2. the octet length: one or more decimal digits specifying the number of octets of the value to be used and formatted by this octet-specification. Note that the octet length can be zero. If less than this number of octets remain in the value, then the lesser number of octets are used. 3. the display format, either: `x' for hexadecimal, `d' for decimal, - `o' for octal, `a' for ASCII, or `t' for UTF-8 [RFC2279]. If the octet length part is greater than one, and the display format part refers to a numeric format, then network byte-ordering (big-endian encoding) is used interpreting the octets in the value. The octets processed by the `t' display format do not necessarily form an integral number of UTF-8 characters. Trailing octets which do not form a valid UTF-8 encoded character are discarded. 4. the (optional) display separator character; if present, this part is a single character which is produced for display after each application of this octet-specification; however, this character is not produced for display if it would be immediately followed by the display of the repeat terminator character for this octet specification. This character can be any character other than a decimal digit and a `*'. 5. the (optional) repeat terminator character, which can be present only if the display separator character is present and this octet specification begins with a repeat indicator; if present, this part is a single character which is produced after all the zero or more repeated applications (as given by the repeat count) of this octet specification. This character can be any character other than a decimal digit and a `*'. Output of a display separator character or a repeat terminator character is suppressed if it would occur as the last character of the display. If the octets of the value are exhausted before all the octet format specification have been used, then the excess specifications are ignored. If additional octets remain in the value after interpreting all the octet format specifications, then the last octet format specification is re-interpreted to process the additional octets, until no octets remain in the value. - Note that for some types no format specifications are defined and - SHOULD be omitted. Implementations MUST ignore format specifications - they cannot interpret. Also note that the SMIng grammar (Appendix A) - does not specify the syntax of format specifications. + Note that for some types no format specifications are defined. For + + derived types and attributes that are based on such types, format + specifications SHOULD be omitted. Implementations MUST ignore format + specifications they cannot interpret. Also note that the SMIng + grammar (Appendix A) does not specify the syntax of format + specifications. Display Format Examples: Base Type Format Example Value Rendered Value ----------- ------------------- ---------------- ----------------- OctetString 255a "Hello World." Hello World. OctetString 1x: "Hello!" 48:65:6c:6c:6f:21 OctetString 1d:1d:1d.1d,1a1d:1d 0x0d1e0f002d0400 13:30:15.0,-4:0 OctetString 1d.1d.1d.1d/2d 0x0a0000010400 10.0.0.1/1024 OctetString *1x:/1x: 0x02aabbccddee aa:bb/cc:dd:ee Integer32 d-2 1234 12.34 4. The SMIng File Structure The topmost container of SMIng information is a file. An SMIng file may contain zero, one or more modules. It is RECOMMENDED to separate - modules into files named by their modules, where possible. Though, + modules into files named by their modules, where possible. However, for dedicated purposes it may be reasonable to collect several modules in a single file. The top level SMIng construct is the `module' statement (Section 5) that defines a single SMIng module. A module contains a sequence of sections in an obligatory order with different kinds of definitions. Whether these sections contain statements or remain empty mainly depends on the purpose of the module. 4.1 Comments - Comments can be included at any position in an SMIng file, except in + Comments can be included at any position in an SMIng file, except between the characters of a single token like those of a quoted string. However, it is RECOMMENDED that all substantive descriptions be placed within an appropriate description clause, so that the information is available to SMIng parsers. Comments commence with a pair of adjacent slashes `//' and end at the end of the line. 4.2 Textual Data Some statements, namely `organization', `contact', `description', `reference', `abnf', `format', and `units', get a textual argument. This text, as well as representations of OctetString values, have to - be enclosed in double quotes. they may contain arbitrary characters + + be enclosed in double quotes. They may contain arbitrary characters with the following exceptional encoding rules: A backslash character introduces a special character, which depends on the character that immediately follows the backslash: \n new line \t a tab character \" a double quote \\ a single backslash If the text contains a line break followed by whitespace which is used to indent the text according to the layout in the SMIng file, this prefixing whitespace is stripped from the text. 4.3 Statements and Arguments SMIng has a very small set of basic grammar rules based on the concept of statements. Each statement starts with a lower-case keyword identifying the statement followed by a number (possibly zero) of arguments. An argument may be quoted text, an identifier, a value of any base type, a list of identifiers enclosed in parenthesis `( )' or a statement block enclosed in curly braces `{ }'. Since statement blocks are valid arguments, it is possible to nest statement sequences. Each statement is terminated by a semicolon `;'. The core set of statements may be extended using the SMIng `extension' statement. See Section 6 and Section 11 for details. At places where a statement is expected, but an unknown lower-case word is read, those statements MUST be skipped up to the proper semicolon, including nested statement blocks. 5. The module Statement The `module' statement is used as a container of all definitions of a single SMIng module. It gets two arguments: an upper-case module name and a statement block that contains mandatory and optional statements and sections of statements in an obligatory order: module { + + }; - The optional `import' statements are followed by the mandatory - `organization', `contact', and `description' statements and the - optional `reference' statement, which in turn are followed by the - mandatory `revision' statements. This part defines the module's meta - information while the following sections contain its main - definitions. + The optional `import' statements (Section 5.1) are followed by the + mandatory `organization' (Section 5.2), `contact' (Section 5.3), and + `description' (Section 5.4) statements and the optional `reference' + statement (Section 5.5), which in turn are followed by at least one + mandatory `revision' statement (Section 5.6). The part up to this + point defines the module's meta information, i.e., information that + describes the whole module but which does not define any items used + by applications in the first instance. This part of a module is + followed by its main definitions, namely SMIng extensions (Section + 6), derived types (Section 7), identities (Section 8), and classes + (Section 9). See the `moduleStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `module' statement. 5.1 The module's import Statement The optional module's `import' statement is used to import identifiers from external modules into the local module's namespace. It gets two arguments: the name of the external module and a comma-separated list of one or more identifiers to be imported enclosed in parenthesis. Multiple `import' statements for the same module but with disjoint lists of identifiers are allowed, though NOT RECOMMENDED. Anyhow, the same identifier from the same module MUST NOT be imported multiple times. To import identifiers with the same name from different modules might be necessary and is allowed. To distinguish them in the local module, they have to be referred by qualified + names. It is NOT RECOMMENDED to import identifiers not used in the local module. See the `importStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `import' statement. 5.2 The module's organization Statement The module's `organization' statement, which must be present, gets one argument which is used to specify a textual description of the organization(s) under whose auspices this module was developed. 5.3 The module's contact Statement The module's `contact' statement, which must be present, gets one argument which is used to specify the name, postal address, telephone number, and electronic mail address of the person to whom technical queries concerning this module should be sent. 5.4 The module's description Statement The module's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the contents of this module. 5.5 The module's reference Statement The module's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related management information, or some other document which provides additional information relevant to this module. 5.6 The module's revision Statement The module's `revision' statement is repeatedly used to specify the editorial revisions of the module, including the initial revision. It gets one argument which is a statement block that holds detailed information in an obligatory order. A module MUST have at least one initial `revision' statement. For every editorial change, a new one MUST be added in front of the revisions sequence, so that all revisions are in reverse chronological order. See the `revisionStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `revision' statement. 5.6.1 The revision's date Statement The revision's `date' statement, which must be present, gets one argument which is used to specify the date and time of the revision in the format `YYYY-MM-DD HH:MM' or `YYYY-MM-DD' which implies the time `00:00'. The time is always given in UTC. See the `date' rule of the SMIng grammar (Appendix A) for the formal - syntax of the revision's `date' statement. 5.6.2 The revision's description Statement The revision's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the revision. 5.7 Usage Example Consider how a skeletal module might be constructed: module ACME-MIB { import NMRG-SMING (DisplayString); organization "IRTF Network Management Research Group (NMRG)"; contact "IRTF Network Management Research Group (NMRG) http://www.ibr.cs.tu-bs.de/projects/nmrg/ Joe L. User ACME, Inc. 42 Anywhere Drive Nowhere, CA 95134 USA Phone: +1 800 555 0815 EMail: joe@acme.example.com"; description "The module for entities implementing the ACME protocol. Copyright (C) The Internet Society (2003). All Rights Reserved. This version of this MIB module is part of RFC XXXX, see the RFC itself for legal notices."; revision { - date "2003-09-19"; + date "2003-10-29"; description "Initial revision, published as RFC XXXX."; }; // ... further definitions ... }; // end of module ACME-MIB. 6. The extension Statement The `extension' statement is used to define new statements to be used in the local module following this extension statement definition or in external modules that may import this extension statement definition. The `extension' statement gets two arguments: a lower-case extension statement identifier and a statement block that holds detailed extension information in an obligatory order. Extension statement identifiers SHOULD NOT contain any upper-case + characters. Note that the SMIng extension feature does not allow to formally specify the context, argument syntax and semantics of an extension. Its only purpose is to declare the existence of an extension and to allow a unique reference to an extension. See Section 11 for - detailed information on extensions and [SNMP] for mappings of SMIng - definitions to SNMP which is formally defined as an extension. + detailed information on extensions and [RFCxxx3] for mappings of + SMIng definitions to SNMP which is formally defined as an extension. See the `extensionStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `extension' statement. 6.1 The extension's status Statement The extension's `status' statement, which must be present, gets one argument which is used to specify whether this extension definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/ existing implementations. 6.2 The extension's description Statement The extension's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the extension statement. It is RECOMMENDED to include information on the extension's context, its semantics, and implementation conditions. See also Section 11. 6.3 The extension's reference Statement The extension's `reference' statement, which need not be present, - gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related extension definitions, or some other document which provides additional information relevant to this extension. 6.4 The extension's abnf Statement The extension's `abnf' statement, which need not be present, gets one argument which is used to specify a formal ABNF [RFC2234] grammar definition of the extension. This grammar can reference rule names from the core SMIng grammar (Appendix A). Note that the `abnf' statement should contain only pure ABNF and no additional text, though comments prefixed by semicolon are allowed but should probably be moved to the description statement. Note that double quotes within the ABNF grammar have to be represented as `\"' according to Section 4.2. 6.5 Usage Example extension severity { status current; description "The optional severity extension statement can only be applied to the statement block of an SMIng class' event definition. If it is present it denotes the severity level of the event in a range from 0 (emergency) to 7 (debug)."; abnf "severityStatement = severityKeyword sep number optsep \";\" severityKeyword = \"severity\""; }; 7. The typedef Statement The `typedef' statement is used to define new data types to be used in the local module or in external modules. It gets two arguments: an upper-case type identifier and a statement block that holds detailed type information in an obligatory order. Type identifiers SHOULD NOT consist of all upper-case characters and SHOULD NOT contain hyphens. See the `typedefStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `typedef' statement. 7.1 The typedef's type Statement The typedef's `type' statement, which must be present, gets one argument which is used to specify the type from which this type is derived. Optionally, type restrictions may be applied to the new type by appending subtyping information according to the rules of the base type. See Section 3 for SMIng base types and their type restrictions. 7.2 The typedef's default Statement The typedef's `default' statement, which need not be present, gets one argument which is used to specify an acceptable default value for attributes of this type. A default value may be used when an + attribute instance is created. That is, the value is a "hint" to implementors. The value of the `default' statement must, of course, correspond to the (probably restricted) type specified in the typedef's `type' statement. The default value of a type may be overwritten by a default value of an attribute of this type. Note that for some types, default values make no sense. 7.3 The typedef's format Statement The typedef's `format' statement, which need not be present, gets one argument which is used to give a hint as to how the value of an instance of an attribute of this type might be displayed. See Section 3.13 for a description of format specifications. If no format is specified, it is inherited from the type given in the `type' statement. On the other hand, the format specification of a type may be semantically refined by a format specification of an attribute of this type. 7.4 The typedef's units Statement The typedef's `units' statement, which need not be present, gets one argument which is used to specify a textual definition of the units associated with attributes of this type. If no units are specified, they are inherited from the type given in the `type' statement. On the other hand, the units specification of a type may be semantically refined by a units specification of an attribute of this type. The units specification has to be appropriate for values displayed - according to the typedef's format specification, if present. E.g., if the type defines frequency values of type Unsigned64 measured in thousands of Hertz, the format specification should be `d-3' and the units specification should be `Hertz' or `Hz'. If the format specification would be omitted, the units specification should be `Milli-Hertz' or `mHz'. Authors of SMIng modules should pay attention to keep format and units specifications synced. Application implementors MUST NOT implement units specifications without implementing format specifications. 7.5 The typedef's status Statement The typedef's `status' statement, which must be present, gets one argument which is used to specify whether this type definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/existing implementations. Derived types SHOULD NOT be defined as `current' if their underlying type is `deprecated' or `obsolete'. Similarly, they SHOULD NOT be defined as `deprecated' if their underlying type is `obsolete'. Nevertheless, subsequent revisions of the underlying type cannot be avoided, but SHOULD be taken into account in subsequent revisions of the local module. 7.6 The typedef's description Statement The typedef's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the newly defined type. It is RECOMMENDED to include all semantic definitions necessary for implementation, and to embody any information which would otherwise be communicated in any commentary annotations associated with this type definition. 7.7 The typedef's reference Statement The typedef's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related type definitions, or some other document which provides additional information relevant to this type definition. 7.8 Usage Examples typedef RptrOperStatus { type Enumeration (other(1), ok(2), rptrFailure(3), groupFailure(4), portFailure(5), generalFailure(6)); default other; // undefined by default. status deprecated; description "A type to indicate the operational state of a repeater."; reference "[IEEE 802.3 Mgt], 30.4.1.1.5, aRepeaterHealthState."; + }; typedef SnmpTransportDomain { type Pointer (snmpTransportDomain); status current; description "A pointer to an SNMP transport domain identity."; }; typedef DateAndTime { type OctetString (8 | 11); format "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"; status current; description "A date-time specification. ... Note that if only local time is known, then timezone information (fields 8-10) is not present."; reference "RFC 2579, SNMPv2-TC.DateAndTime."; }; typedef Frequency { type Unsigned64; format "d-3" units "Hertz"; status current; description "A wide-range frequency specification measured in thousands of Hertz."; }; 8. The identity Statement The `identity' statement is used to define a new abstract and untyped identity. Its only purpose is to denote its name, semantics and existence. An identity can be defined either from scratch or derived - from a parent identity. The `identity' statement gets the following two arguments: The first argument is a lower-case identity identifier. The second argument is a statement block that holds detailed identity information in an obligatory order. See the `identityStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `identity' statement. 8.1 The identity's parent Statement The identity's `parent' statement must be present for a derived + identity and must be absent for an identity defined from scratch. It gets one argument which is used to specify the parent identity from which this identity shall be derived. 8.2 The identity's status Statement The identity's `status' statement, which must be present, gets one argument which is used to specify whether this identity definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/existing implementations. Derived identities SHOULD NOT be defined as `current' if their parent identity is `deprecated' or `obsolete'. Similarly, they SHOULD NOT be defined as `deprecated' if their parent identity is `obsolete'. Nevertheless, subsequent revisions of the parent identity cannot be avoided, but SHOULD be taken into account in subsequent revisions of the local module. 8.3 The identity' description Statement The identity's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the newly defined identity. It is RECOMMENDED to include all semantic definitions necessary for implementation, and to embody any information which would otherwise be communicated in any commentary annotations associated with this identity definition. 8.4 The identity's reference Statement The identity's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to - some other document, either another module which defines related identity definitions, or some other document which provides additional information relevant to this identity definition. 8.5 Usage Examples identity null { status current; description "An identity used to represent null pointer values."; }; identity snmpTransportDomain { status current; description "A generic SNMP transport domain identity."; }; identity snmpUDPDomain { parent snmpTransportDomain; status current; description "The SNMP over UDP transport domain."; }; 9. The class Statement The `class' statement is used to define a new class, that represents a container of related attributes and events (Section 9.2, Section 9.4). A class can be defined either from scratch or derived from a parent class. A derived class inherits all attributes and events of the parent class and can be extended by additional attributes and events. The `class' statement gets the following two arguments: The first argument is an upper-case class identifier. The second argument is a statement block that holds detailed class information in an obligatory order. See the `classStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `class' statement. 9.1 The class' extends Statement The class' `extends' statement must be present for a class derived from a parent class and must be absent for a class defined from scratch. It gets one argument which is used to specify the parent class from which this class shall be derived. 9.2 The class' attribute Statement The class' `attribute' statement, which can be present zero, one or + multiple times, gets two arguments: the attribute name and a statement block that holds detailed attribute information in an obligatory order. 9.2.1 The attribute's type Statement The attribute's `type' statement must be present. It gets at least one argument which is used to specify the type of the attribute: either a type name or a class name. In case of a type name, it may be restricted by a second argument according to the restriction rules described in Section 3. 9.2.2 The attribute's access Statement The attribute's `access' statement must be present for attributes typed by a base type or derived type, and must be absent for attributes typed by a class. It gets one argument which is used to specify whether it makes sense to read and/or write an instance of the attribute, or to include its value in an event. This is the maximal level of access for the attribute. This maximal level of access is independent of any administrative authorization policy. The value `readwrite' indicates that read and write access makes sense. The value `readonly' indicates that read access makes sense, but write access is never possible. The value `eventonly' indicates an object which is accessible only via an event. These values are ordered, from least to greatest access level: `eventonly', `readonly', `readwrite'. 9.2.3 The attribute's default Statement The attribute's `default' statement need not be present for attributes typed by a base type or derived type, and must be absent for attributes typed by a class. It gets one argument which is used to specify an acceptable default value for this attribute. A default value may be used when an attribute instance is created. That is, the value is a "hint" to implementors. The value of the `default' statement must, of course, correspond to the (probably restricted) type specified in the attribute's `type' statement. The attribute's default value overrides the default value of the underlying type definition if both are present. 9.2.4 The attribute's format Statement The attribute's `format' statement need not be present for attributes typed by a base type or derived type, and must be absent for attributes typed by a class. It gets one argument which is used to give a hint as to how the value of an instance of this attribute might be displayed. See Section 3.13 for a description of format specifications. The attribute's format specification overrides the format specification of the underlying type definition if both are present. 9.2.5 The attribute's units Statement The attribute's `units' statement need not be present for attributes typed by a base type or derived type, and must be absent for attributes typed by a class. It gets one argument which is used to specify a textual definition of the units associated with this attribute. The attribute's units specification overrides the units specification of the underlying type definition if both are present. The units specification has to be appropriate for values displayed according to the attribute's format specification if present. E.g., if the attribute represents a frequency value of type Unsigned64 measured in thousands of Hertz, the format specification should be `d-3' and the units specification should be `Hertz' or `Hz'. If the format specification would be omitted the units specification should be `Milli-Hertz' or `mHz'. Authors of SMIng modules should pay attention to keep format and units specifications of type and attribute definitions synced. Application implementors MUST NOT implement units specifications without implementing format specifications. 9.2.6 The attribute's status Statement The attribute's `status' statement must be present. It gets one argument which is used to specify whether this attribute definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/ existing implementations. Attributes SHOULD NOT be defined as `current' if their type or their - containing class is `deprecated' or `obsolete'. Similarly, they SHOULD NOT be defined as `deprecated' if their type or their + containting class is `obsolete'. Nevertheless, subsequent revisions of used type definition cannot be avoided, but SHOULD be taken into account in subsequent revisions of the local module. 9.2.7 The attribute's description Statement The attribute's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of this attribute. It is RECOMMENDED to include all semantic definitions necessary for the implementation of this attribute. 9.2.8 The attribute's reference Statement The attribute's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related attribute definitions, or some other document which provides additional information relevant to this attribute definition. 9.3 The class' unique Statement The class' `unique' statement, which need not be present, gets one argument that specifies a comma-separated list of attributes of this class, enclosed in parenthesis. If present, this list of attributes makes up a unique identification of all possible instances of this class. It can be used as a unique key in underlying protocols. If the list is empty the class should be regarded as a scalar class with only a single instance. If the `unique' statement is not present the class is not meant to be instantiated directly, but just to be contained in other classes or to be the parent class of other refining classes. If present, the attribute list MUST NOT contain any attribute more than once and the attributes should be ordered where appropriate so that the attributes that are most significant in most situations appear first. 9.4 The class' event Statement The class' `event' statement is used to define an event related to an instance of this class that can occur asynchronously. It gets two arguments: a lower-case event identifier and a statement block that - holds detailed information in an obligatory order. See the `eventStatement' rule of the SMIng grammar (Appendix A) for the formal syntax of the `event' statement. 9.4.1 The event's status Statement The event's `status' statement, which must be present, gets one argument which is used to specify whether this event definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/existing implementations. 9.4.2 The event's description Statement The event's `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of this event. It is RECOMMENDED to include all semantic definitions necessary for the implementation of this event. In particular, it SHOULD be documented which instance of the class is associated with an event of this type. 9.4.3 The event's reference Statement The event's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related event definitions, or some other document which provides additional information relevant to this event definition. 9.5 The class' status Statement The class' `status' statement, which must be present, gets one argument which is used to specify whether this class definition is current or historic. The value `current' means that the definition is current and valid. The value `obsolete' means the definition is obsolete and should not be implemented and/or can be removed if previously implemented. While the value `deprecated' also indicates an obsolete definition, it permits new/continued implementation in order to foster interoperability with older/existing implementations. Derived classes SHOULD NOT be defined as `current' if their parent class is `deprecated' or `obsolete'. Similarly, they SHOULD NOT be - defined as `deprecated' if their parent class is `obsolete'. Nevertheless, subsequent revisions of the parent class cannot be + avoided, but SHOULD be taken into account in subsequent revisions of the local module. 9.6 The class' description Statement The class' `description' statement, which must be present, gets one argument which is used to specify a high-level textual description of the newly defined class. It is RECOMMENDED to include all semantic definitions necessary for implementation, and to embody any information which would otherwise be communicated in any commentary annotations associated with this class definition. 9.7 The class's reference Statement The class's `reference' statement, which need not be present, gets one argument which is used to specify a textual cross-reference to some other document, either another module which defines related class definitions, or some other document which provides additional information relevant to this class definition. 9.8 Usage Example Consider how an event might be described that signals a status change of an interface: class Interface { // ... attribute speed { type Gauge32; access readonly; units "bps"; status current; description "An estimate of the interface's current bandwidth in bits per second."; }; // ... attribute adminStatus { type AdminStatus; access readwrite; status current; description "The desired state of the interface."; }; - attribute operStatus { type OperStatus; + access readonly; status current; description "The current operational state of the interface."; }; event linkDown { status current; description "A linkDown event signifies that the ifOperStatus attribute for this interface instance is about to enter the down state from some other state (but not from the notPresent state). This other state is indicated by the included value of ifOperStatus."; }; status current; description "A physical or logical network interface."; }; 10. Extending a Module As experience is gained with a module, it may be desirable to revise that module. However, changes are not allowed if they have any potential to cause interoperability problems between an implementation using an original specification and an implementation using an updated specification(s). For any change, some statements near the top of the module MUST be updated to include information about the revision: specifically, a new `revision' statement (Section 5.6) must be included in front of the `revision' statements. Furthermore, any necessary changes MUST be applied to other statements, including the `organization' and `contact' statements (Section 5.2, Section 5.3). Note that any definition contained in a module is available to be imported by any other module, and is referenced in an `import' statement via the module name. Thus, a module name MUST NOT be changed. Specifically, the module name (e.g., `ACME-MIB' in the example of Section 5.7) MUST NOT be changed when revising a module (except to correct typographical errors), and definitions MUST NOT be moved from one module to another. Also note, that obsolete definitions MUST NOT be removed from modules - since their identifiers may still be referenced by other modules. A definition may be revised in any of the following ways: o In `typedef' statement blocks, a `type' statement containing an `Enumeration' or `Bits' type may have new named numbers added. o In `typedef' statement blocks, the value of a `type' statement may be replaced by another type if the new type is derived (directly or indirectly) from the same base type, has the same set of values, and has identical semantics. o In `attribute' statements where the `type' sub-statement specifies a class, the class may be replaced by another class if the new class is derived (directly or indirectly) from the base class and both classes have identical semantics. o In `attribute' statements where the `type' sub-statement specifies a base type, a defined type, or an implicitly derived type (i.e. not a class), that type may be replaced by another type if the new type is derived (directly or indirectly) from the same base type, has the same set of values, and has identical semantics. o In any statement block, a `status' statement value of `current' may be revised as `deprecated' or `obsolete'. Similarly, a `status' statement value of `deprecated' may be revised as `obsolete'. When making such a change, the `description' statement SHOULD be updated to explain the rationale. o In `typedef' and `attribute' statement blocks, a `default' statement may be added or updated. o In `typedef' and `attribute' statement blocks, a `units' statement may be added. o A class may be augmented by adding new attributes. o In any statement block, clarifications and additional information may be included in the `description' statement. o In any statement block, a `reference' statement may be added or updated. o Entirely new extensions, types, identities, and classes may be defined, using previously unassigned identifiers. Otherwise, if the semantics of any previous definition are changed (i.e., if a non-editorial change is made to any definition other than - those specifically allowed above), then this MUST be achieved by a new definition with a new identifier. In case of a class where the + semantics of any attributes are changed, the new class can be defined by derivation from the old class and refining the changed attributes. Note that changing the identifier associated with an existing definition is considered a semantic change, as these strings may be used in an `import' statement. 11. SMIng Language Extensibility While the core SMIng language has a well defined set of statements (Section 5 through Section 9.4) that are used to specify those aspects of management information commonly regarded as necessary without management protocol specific information, there may be further information, people wish to express. To describe additional information informally in description statements has the disadvantage that this information cannot be parsed by any program. SMIng allows modules to include statements that are unknown to a parser but fulfill some core grammar rules (Section 4.3). Furthermore, additional statements may be defined by the `extension' statement (Section 6). Extensions can be used in the local module or in other modules, that import the extension. This has some advantages: o A parser can differentiate between statements known as extensions and unknown statements. This enables the parser to complain about unknown statements, e.g. due to typos. o If an extension's definition contains a formal ABNF grammar definition and a parser is able to interpret this ABNF definition, this enables the parser also to complain about wrong usage of an extension. o Since, there might be some common need for extensions, there is a relatively high probability of extension name collisions originated by different organizations, as long as there is no standardized extension for that purpose. The requirement to explicitly import extension statements allows to distinguish those extensions. o The supported extensions of an SMIng implementation, e.g. an SMIng module compiler, can be clearly expressed. The only formal effect of an extension statement definition is to declare its existence and its status, and optionally its ABNF grammar. All additional aspects SHOULD be described in the - `description' statement: o The detailed semantics of the new statement SHOULD be described. o The contexts in which the new statement can be used, SHOULD be described, e.g., a new statement may be designed to be used only in the statement block of a module, but not in other nested statement blocks. Others may be applicable in multiple contexts. In addition, the point in the sequence of an obligatory order of other statements, where the new statement may be inserted, might be prescribed. o The circumstances that make the new statement mandatory or optional SHOULD be described. o The syntax of the new statement SHOULD at least be described informally, if not supplied formally in an `abnf' statement. o It might be reasonable to give some suggestions under which conditions the implementation of the new statement is adequate and how it could be integrated into existent implementations. Some possible extension applications are: - o The formal mapping of SMIng definitions into the SNMP [SNMP] + o The formal mapping of SMIng definitions into the SNMP [RFCxxx3] framework is defined as an SMIng extension. Other mappings may follow in the future. o Inlined annotations to definitions. E.g., a vendor may wish to describe additional information to class and attribute definitions in private modules. An example are severity levels of events in the statement block of an `event' statement. o Arbitrary annotations to external definitions. E.g., a vendor may wish to describe additional information to definitions in a "standard" module. This allows a vendor to implement "standard" modules as well as additional private features, without redundant module definitions, but on top of "standard" module definitions. 12. Security Considerations This document defines a language with which to write and read descriptions of management information. The language itself has no security impact on the Internet. 13. Acknowledgements Since SMIng started as a close successor of SMIv2, some paragraphs and phrases are directly taken from the SMIv2 specifications + [RFC2578], [RFC2579], [RFC2580] written by Jeff Case, Keith McCloghrie, David Perkins, Marshall T. Rose, Juergen Schoenwaelder, and Steven L. Waldbusser. The authors would like to thank all participants of the 7th NMRG meeting held in Schloss Kleinheubach from 6-8 September 2000, which was a major step towards the current status of this memo, namely - Heiko Dassow, David Durham, and Bert Wijnen. + Heiko Dassow, David Durham, Keith McCloghrie, and Bert Wijnen. Furthmore, several discussions within the SMING Working Group reflected experience with SMIv2 and influenced this specification at some points. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997. [RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. Informative References [RFC3216] Elliott, C., Harrington, D., Jason, J., Schoenwaelder, J., Strauss, F. and W. Weiss, "SMIng Objectives", RFC 3216, December 2001. - [Modules] Strauss, F. and J. Schoenwaelder, "SMIng Core Modules", - draft-irtf-nmrg-sming-modules-03.txt, September 2003. + [RFCxxx2] Strauss, F. and J. Schoenwaelder, "SMIng Core Modules", + draft-irtf-nmrg-sming-modules-04.txt, October 2003. - [SNMP] Strauss, F. and J. Schoenwaelder, "SMIng Extension for - SNMP Mappings", draft-irtf-nmrg-sming-snmp-03.txt, - September 2003. + [RFCxxx3] Strauss, F. and J. Schoenwaelder, "SMIng Extension for + SNMP Mappings", draft-irtf-nmrg-sming-snmp-04.txt, October + 2003. [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Structure of Management Information Version 2 (SMIv2)", RFC 2578, STD 58, April 1999. [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Textual Conventions for SMIv2", RFC 2579, STD 59, April 1999. [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Conformance Statements for SMIv2", RFC 2580, STD 60, April 1999. [RFC3159] McCloghrie, K., Fine, M., Seligson, J., Chan, K., Hahn, + S., Sahita, R., Smith, A. and F. Reichmeyer, "Structure of Policy Provisioning Information (SPPI)", RFC 3159, August 2001. [RFC1155] Rose, M. and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", RFC 1155, STD 16, May 1990. [RFC1212] Rose, M. and K. McCloghrie, "Concise MIB Definitions", RFC 1212, STD 16, March 1991. [RFC1215] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, March 1991. [ASN1] International Organization for Standardization, "Specification of Abstract Syntax Notation One (ASN.1)", International Standard 8824, December 1987. [RFC3411] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks", RFC 3411, STD 62, December 2002. [IEEE754] Institute of Electrical and Electronics Engineers, "IEEE Standard for Binary Floating-Point Arithmetic", ANSI/IEEE Standard 754-1985, August 1985. [RFC2279] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC 2279, January 1998. Authors' Addresses Frank Strauss TU Braunschweig Muehlenpfordtstrasse 23 38106 Braunschweig Germany Phone: +49 531 391 3266 EMail: strauss@ibr.cs.tu-bs.de URI: http://www.ibr.cs.tu-bs.de/ Juergen Schoenwaelder International University Bremen P.O. Box 750 561 28725 Bremen Germany Phone: +49 421 200 3587 EMail: j.schoenwaelder@iu-bremen.de URI: http://www.eecs.iu-bremen.de/ Appendix A. SMIng ABNF Grammar The SMIng grammar conforms to the Augmented Backus-Naur Form (ABNF) [RFC2234]. ;; ;; sming.abnf -- SMIng grammar in ABNF notation (RFC 2234). ;; - ;; @(#) $Id: sming.abnf,v 1.32 2003/07/22 16:55:34 strauss Exp $ + ;; @(#) $Id: sming.abnf,v 1.33 2003/10/23 19:31:55 strauss Exp $ ;; ;; Copyright (C) The Internet Society (2003). All Rights Reserved. ;; smingFile = optsep *(moduleStatement optsep) ;; ;; Statement rules. ;; moduleStatement = moduleKeyword sep ucIdentifier optsep "{" stmtsep *(importStatement stmtsep) organizationStatement stmtsep contactStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) 1*(revisionStatement stmtsep) *(extensionStatement stmtsep) *(typedefStatement stmtsep) *(identityStatement stmtsep) *(classStatement stmtsep) "}" optsep ";" extensionStatement = extensionKeyword sep lcIdentifier optsep "{" stmtsep statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) *1(abnfStatement stmtsep) "}" optsep ";" typedefStatement = typedefKeyword sep ucIdentifier optsep "{" stmtsep typedefTypeStatement stmtsep *1(defaultStatement stmtsep) *1(formatStatement stmtsep) *1(unitsStatement stmtsep) statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) "}" optsep ";" identityStatement = identityStmtKeyword sep lcIdentifier optsep "{" stmtsep *1(parentStatement stmtsep) statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) "}" optsep ";" classStatement = classKeyword sep ucIdentifier optsep "{" stmtsep *1(extendsStatement stmtsep) *(attributeStatement stmtsep) *1(uniqueStatement stmtsep) *(eventStatement stmtsep) statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) "}" optsep ";" attributeStatement = attributeKeyword sep lcIdentifier optsep "{" stmtsep typeStatement stmtsep *1(accessStatement stmtsep) *1(defaultStatement stmtsep) *1(formatStatement stmtsep) *1(unitsStatement stmtsep) statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) "}" optsep ";" uniqueStatement = uniqueKeyword optsep "(" optsep qlcIdentifierList optsep ")" optsep ";" eventStatement = eventKeyword sep lcIdentifier optsep "{" stmtsep statusStatement stmtsep descriptionStatement stmtsep *1(referenceStatement stmtsep) "}" optsep ";" importStatement = importKeyword sep ucIdentifier optsep "(" optsep identifierList optsep ")" optsep ";" revisionStatement = revisionKeyword optsep "{" stmtsep dateStatement stmtsep descriptionStatement stmtsep "}" optsep ";" typedefTypeStatement = typeKeyword sep refinedBaseType optsep ";" typeStatement = typeKeyword sep (refinedBaseType / refinedType) optsep ";" parentStatement = parentKeyword sep qlcIdentifier optsep ";" extendsStatement = extendsKeyword sep qucIdentifier optsep ";" dateStatement = dateKeyword sep date optsep ";" organizationStatement = organizationKeyword sep text optsep ";" contactStatement = contactKeyword sep text optsep ";" formatStatement = formatKeyword sep format optsep ";" unitsStatement = unitsKeyword sep units optsep ";" statusStatement = statusKeyword sep status optsep ";" accessStatement = accessKeyword sep access optsep ";" defaultStatement = defaultKeyword sep anyValue optsep ";" descriptionStatement = descriptionKeyword sep text optsep ";" referenceStatement = referenceKeyword sep text optsep ";" abnfStatement = abnfKeyword sep text optsep ";" ;; refinedBaseType = ObjectIdentifierKeyword / OctetStringKeyword *1(optsep numberSpec) / PointerKeyword *1(optsep pointerSpec) / Integer32Keyword *1(optsep numberSpec) / Unsigned32Keyword *1(optsep numberSpec) / Integer64Keyword *1(optsep numberSpec) / Unsigned64Keyword *1(optsep numberSpec) / Float32Keyword *1(optsep floatSpec) / Float64Keyword *1(optsep floatSpec) / Float128Keyword *1(optsep floatSpec) / EnumerationKeyword optsep namedSignedNumberSpec / BitsKeyword optsep namedNumberSpec refinedType = qucIdentifier *1(optsep anySpec) anySpec = pointerSpec / numberSpec / floatSpec pointerSpec = "(" optsep qlcIdentifier optsep ")" numberSpec = "(" optsep numberElement *furtherNumberElement optsep ")" furtherNumberElement = optsep "|" optsep numberElement numberElement = signedNumber *1numberUpperLimit numberUpperLimit = optsep ".." optsep signedNumber floatSpec = "(" optsep floatElement *furtherFloatElement optsep ")" furtherFloatElement = optsep "|" optsep floatElement floatElement = floatValue *1floatUpperLimit floatUpperLimit = optsep ".." optsep floatValue namedNumberSpec = "(" optsep namedNumberList optsep ")" namedNumberList = namedNumberItem *(optsep "," optsep namedNumberItem) namedNumberItem = lcIdentifier optsep "(" optsep number optsep ")" namedSignedNumberSpec = "(" optsep namedSignedNumberList optsep ")" namedSignedNumberList = namedSignedNumberItem *(optsep "," optsep namedSignedNumberItem) namedSignedNumberItem = lcIdentifier optsep "(" optsep signedNumber optsep ")" identifierList = identifier *(optsep "," optsep identifier) qIdentifierList = qIdentifier *(optsep "," optsep qIdentifier) qlcIdentifierList = qlcIdentifier *(optsep "," optsep qlcIdentifier) bitsValue = "(" optsep bitsList optsep ")" bitsList = *1(lcIdentifier *(optsep "," optsep lcIdentifier)) ;; ;; Other basic rules. ;; identifier = ucIdentifier / lcIdentifier qIdentifier = qucIdentifier / qlcIdentifier ucIdentifier = ucAlpha *63(ALPHA / DIGIT / "-") qucIdentifier = *1(ucIdentifier "::") ucIdentifier lcIdentifier = lcAlpha *63(ALPHA / DIGIT / "-") qlcIdentifier = *1(ucIdentifier "::") lcIdentifier attrIdentifier = lcIdentifier *("." lcIdentifier) qattrIdentifier = *1(ucIdentifier ".") attrIdentifier cattrIdentifier = ucIdentifier "." lcIdentifier *("." lcIdentifier) qcattrIdentifier = qucIdentifier "." lcIdentifier *("." lcIdentifier) text = textSegment *(optsep textSegment) textSegment = DQUOTE *textAtom DQUOTE ; See Section 4.2. textAtom = textVChar / HTAB / SP / lineBreak date = DQUOTE 4DIGIT "-" 2DIGIT "-" 2DIGIT *1(" " 2DIGIT ":" 2DIGIT) DQUOTE ; always in UTC format = textSegment units = textSegment anyValue = bitsValue / signedNumber / hexadecimalNumber / floatValue / text / objectIdentifier ; Note: `objectIdentifier' includes the ; syntax of enumeration labels and ; identities. ; They are not named literally to ; avoid reduce/reduce conflicts when ; building LR parsers based on this ; grammar. status = currentKeyword / deprecatedKeyword / obsoleteKeyword access = eventonlyKeyword / readonlyKeyword / readwriteKeyword objectIdentifier = (qlcIdentifier / subid "." subid) *127("." subid) subid = decimalNumber number = hexadecimalNumber / decimalNumber negativeNumber = "-" decimalNumber signedNumber = number / negativeNumber decimalNumber = "0" / (nonZeroDigit *DIGIT) zeroDecimalNumber = 1*DIGIT hexadecimalNumber = %x30 %x78 ; "0x" with x only lower-case 1*(HEXDIG HEXDIG) floatValue = neginfKeyword / posinfKeyword / snanKeyword / qnanKeyword / signedNumber "." zeroDecimalNumber *1("E" ("+"/"-") zeroDecimalNumber) ;; ;; Rules to skip unknown statements ;; with arbitrary arguments and blocks. ;; unknownStatement = unknownKeyword optsep *unknownArgument optsep ";" unknownArgument = ("(" optsep unknownList optsep ")") / ("{" optsep *unknownStatement optsep "}") / qucIdentifier / anyValue / anySpec unknownList = namedNumberList / qIdentifierList unknownKeyword = lcIdentifier ;; ;; Keyword rules. ;; ;; Typically, keywords are represented by tokens returned from the ;; lexical analyzer. Note, that the lexer has to be stateful to ;; distinguish keywords from identifiers depending on the context ;; position in the input stream. ;; moduleKeyword = %x6D %x6F %x64 %x75 %x6C %x65 importKeyword = %x69 %x6D %x70 %x6F %x72 %x74 revisionKeyword = %x72 %x65 %x76 %x69 %x73 %x69 %x6F %x6E dateKeyword = %x64 %x61 %x74 %x65 organizationKeyword = %x6F %x72 %x67 %x61 %x6E %x69 %x7A %x61 %x74 %x69 %x6F %x6E contactKeyword = %x63 %x6F %x6E %x74 %x61 %x63 %x74 descriptionKeyword = %x64 %x65 %x73 %x63 %x72 %x69 %x70 %x74 %x69 %x6F %x6E referenceKeyword = %x72 %x65 %x66 %x65 %x72 %x65 %x6E %x63 %x65 extensionKeyword = %x65 %x78 %x74 %x65 %x6E %x73 %x69 %x6F %x6E typedefKeyword = %x74 %x79 %x70 %x65 %x64 %x65 %x66 typeKeyword = %x74 %x79 %x70 %x65 parentKeyword = %x70 %x61 %x72 %x65 %x6E %x74 identityStmtKeyword = %x69 %x64 %x65 %x6E %x74 %x69 %x74 %x79 classKeyword = %x63 %x6C %x61 %x73 %x73 extendsKeyword = %x65 %x78 %x74 %x65 %x6E %x64 %x73 attributeKeyword = %x61 %x74 %x74 %x72 %x69 %x62 %x75 %x74 %x65 uniqueKeyword = %x75 %x6E %x69 %x71 %x75 %x65 eventKeyword = %x65 %x76 %x65 %x6E %x74 formatKeyword = %x66 %x6F %x72 %x6D %x61 %x74 unitsKeyword = %x75 %x6E %x69 %x74 %x73 statusKeyword = %x73 %x74 %x61 %x74 %x75 %x73 accessKeyword = %x61 %x63 %x63 %x65 %x73 %x73 defaultKeyword = %x64 %x65 %x66 %x61 %x75 %x6C %x74 abnfKeyword = %x61 %x62 %x6E %x66 ;; Base type keywords. OctetStringKeyword = %x4F %x63 %x74 %x65 %x74 %x53 %x74 %x72 %x69 %x6E %x67 PointerKeyword = %x50 %x6F %x69 %x6E %x74 %x65 %x72 ObjectIdentifierKeyword = %x4F %x62 %x6A %x65 %x63 %x74 %x49 %x64 %x65 %x6E %x74 %x69 %x66 %x69 %x65 %x72 Integer32Keyword = %x49 %x6E %x74 %x65 %x67 %x65 %x72 %x33 %x32 Unsigned32Keyword = %x55 %x6E %x73 %x69 %x67 %x6E %x65 %x64 %x33 %x32 Integer64Keyword = %x49 %x6E %x74 %x65 %x67 %x65 %x72 %x36 %x34 Unsigned64Keyword = %x55 %x6E %x73 %x69 %x67 %x6E %x65 %x64 %x36 %x34 Float32Keyword = %x46 %x6C %x6F %x61 %x74 %x33 %x32 Float64Keyword = %x46 %x6C %x6F %x61 %x74 %x36 %x34 Float128Keyword = %x46 %x6C %x6F %x61 %x74 %x31 %x32 %x38 BitsKeyword = %x42 %x69 %x74 %x73 EnumerationKeyword = %x45 %x6E %x75 %x6D %x65 %x72 %x61 %x74 %x69 %x6F %x6E ;; Status keywords. currentKeyword = %x63 %x75 %x72 %x72 %x65 %x6E %x74 deprecatedKeyword = %x64 %x65 %x70 %x72 %x65 %x63 %x61 %x74 %x65 %x64 obsoleteKeyword = %x6F %x62 %x73 %x6F %x6C %x65 %x74 %x65 ;; Access keywords. eventonlyKeyword = %x65 %x76 %x65 %x6E %x74 %x6F %x6E %x6C %x79 readonlyKeyword = %x72 %x65 %x61 %x64 %x6F %x6E %x6C %x79 readwriteKeyword = %x72 %x65 %x61 %x64 %x77 %x72 %x69 %x74 %x65 ;; Special floating point values' keywords. neginfKeyword = %x6E %x65 %x67 %x69 %x6E %x66 posinfKeyword = %x70 %x6F %x73 %x69 %x6E %x66 snanKeyword = %x73 %x6E %x61 %x6E qnanKeyword = %x71 %x6E %x61 %x6E ;; ;; Some low level rules. ;; These tokens are typically skipped by the lexical analyzer. ;; sep = 1*(comment / lineBreak / WSP) ; unconditional separator optsep = *(comment / lineBreak / WSP) stmtsep = *(comment / lineBreak / WSP / unknownStatement) comment = "//" *(WSP / VCHAR) lineBreak lineBreak = CRLF / LF ;; ;; Encoding specific rules. ;; textVChar = %x21 / %x23-7E ; any VCHAR except DQUOTE ucAlpha = %x41-5A lcAlpha = %x61-7A nonZeroDigit = %x31-39 ;; ;; RFC 2234 core rules. ;; ALPHA = %x41-5A / %x61-7A ; A-Z / a-z CR = %x0D ; carriage return CRLF = CR LF ; Internet standard newline DIGIT = %x30-39 ; 0-9 DQUOTE = %x22 ; " (Double Quote) HEXDIG = DIGIT / %x61 / %x62 / %x63 / %x64 / %x65 / %x66 ; only lower-case a..f HTAB = %x09 ; horizontal tab LF = %x0A ; linefeed SP = %x20 ; space VCHAR = %x21-7E ; visible (printing) characters WSP = SP / HTAB ; white space + + ;; End of ABNF Intellectual Property Statement 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. 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