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RFC 3780

 
 
 

SMIng - Next Generation Structure of Management Information

Part 3 of 3, p. 41 to 64
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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, Keith McCloghrie, and Bert Wijnen.

   Furthermore, several discussions within the SMING Working Group
   reflected experience with SMIv2 and influenced this specification at
   some points.

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14.  References

14.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", RFC 2234, November 1997.

14.2.  Informative References

   [RFC3216]  Elliott, C., Harrington, D., Jason, J., Schoenwaelder, J.,
              Strauss, F. and W. Weiss, "SMIng Objectives", RFC 3216,
              December 2001.

   [RFC3781]  Strauss, F. and J. Schoenwaelder, "Next Generation
              Structure of Management Information (SMIng) Mappings to
              the Simple Network Management Protocol (SNMP)", RFC 3781,
              May 2004.

   [RFC2578]  McCloghrie, K., Perkins, D. and J. Schoenwaelder,
              "Structure of Management Information Version 2 (SMIv2)",
              STD 58, RFC 2578, April 1999.

   [RFC2579]  McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual
              Conventions for SMIv2", STD 59, RFC 2579, April 1999.

   [RFC2580]  McCloghrie, K., Perkins, D. and J. Schoenwaelder,
              "Conformance Statements for SMIv2", STD 60, RFC 2580,
              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", STD
              16, RFC 1155, May 1990.

   [RFC1212]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD
              16, RFC 1212, March 1991.

   [RFC1215]  Rose, M., "A Convention for Defining Traps for use with
              the SNMP", RFC 1215, March 1991.

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   [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", STD 62, RFC 3411,
              December 2002.

   [IEEE754]  Institute of Electrical and Electronics Engineers, "IEEE
              Standard for Binary Floating-Point Arithmetic", ANSI/IEEE
              Standard 754-1985, August 1985.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, November 2003.

   [RFC3084]  Chan, K., Seligson, J., Durham, D., Gai, S., McCloghrie,
              K., Herzog, S., Reichmeyer, F., Yavatkar, R. and A. Smith,
              "COPS Usage for Policy Provisioning", RFC 3084, March
              2001.

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Appendix A. NMRG-SMING Module

   Most SMIng modules are built on top of the definitions of some
   commonly used derived types.  The definitions of these derived types
   are contained in the NMRG-SMING module which is defined below.  Its
   derived types are generally applicable for modeling all areas of
   management information.  Among these derived types are counter types,
   string types, and date and time related types.

   This module is derived from RFC 2578 [RFC2578] and RFC 2579
   [RFC2579].

module NMRG-SMING {

    organization    "IRTF Network Management Research Group (NMRG)";

    contact         "IRTF Network Management Research Group (NMRG)
                     http://www.ibr.cs.tu-bs.de/projects/nmrg/

                     Frank Strauss
                     TU Braunschweig
                     Muehlenpfordtstrasse 23
                     38106 Braunschweig
                     Germany
                     Phone: +49 531 391 3266
                     EMail: strauss@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";

    description     "Core type definitions for SMIng. Several
                     type definitions are SMIng versions of
                     similar SMIv2 or SPPI definitions.

                     Copyright (C) The Internet Society (2004).
                     All Rights Reserved.
                     This version of this module is part of
                     RFC 3780, see the RFC itself for full
                     legal notices.";

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    revision {
        date        "2003-12-16";
        description "Initial revision, published as RFC 3780.";
    };

    typedef Gauge32 {
        type        Unsigned32;
        description
           "The Gauge32 type represents a non-negative integer,
            which may increase or decrease, but shall never
            exceed a maximum value, nor fall below a minimum
            value.  The maximum value can not be greater than
            2^32-1 (4294967295 decimal), and the minimum value
            can not be smaller than 0.  The value of a Gauge32
            has its maximum value whenever the information
            being modeled is greater than or equal to its
            maximum value, and has its minimum value whenever
            the information being modeled is smaller than or
            equal to its minimum value.  If the information
            being modeled subsequently decreases below
            (increases above) the maximum (minimum) value, the
            Gauge32 also decreases (increases).";
        reference
           "RFC 2578, Sections 2. and 7.1.7.";
    };

    typedef Counter32 {
        type        Unsigned32;
        description
           "The Counter32 type represents a non-negative integer
            which monotonically increases until it reaches a
            maximum value of 2^32-1 (4294967295 decimal), when it
            wraps around and starts increasing again from zero.

            Counters have no defined `initial' value, and thus, a
            single value of a Counter has (in general) no information
            content.  Discontinuities in the monotonically increasing
            value normally occur at re-initialization of the
            management system, and at other times as specified in the
            description of an attribute using this type.  If such
            other times can occur, for example, the creation of a
            class instance that contains an attribute of type
            Counter32 at times other than re-initialization, then a
            corresponding attribute should be defined, with an
            appropriate type, to indicate the last discontinuity.
            Examples of appropriate types include: TimeStamp32,
            TimeStamp64, DateAndTime, TimeTicks32 or TimeTicks64
            (other types defined in this module).

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            The value of the access statement for attributes with
            a type value of Counter32 should be either `readonly'
            or `eventonly'.

            A default statement should not be used for attributes
            with a type value of Counter32.";
        reference
           "RFC 2578, Sections 2. and 7.1.6.";
    };

    typedef Gauge64 {
        type        Unsigned64;
        description
           "The Gauge64 type represents a non-negative integer,
            which may increase or decrease, but shall never
            exceed a maximum value, nor fall below a minimum
            value.  The maximum value can not be greater than
            2^64-1 (18446744073709551615), and the minimum value
            can not be smaller than 0.  The value of a Gauge64
            has its maximum value whenever the information
            being modeled is greater than or equal to its
            maximum value, and has its minimum value whenever
            the information being modeled is smaller than or
            equal to its minimum value.  If the information
            being modeled subsequently decreases below
            (increases above) the maximum (minimum) value, the
            Gauge64 also decreases (increases).";
    };

    typedef Counter64 {
        type        Unsigned64;
        description
           "The Counter64 type represents a non-negative integer
            which monotonically increases until it reaches a
            maximum value of 2^64-1 (18446744073709551615), when
            it wraps around and starts increasing again from zero.

            Counters have no defined `initial' value, and thus, a
            single value of a Counter has (in general) no
            information content.  Discontinuities in the
            monotonically increasing value normally occur at
            re-initialization of the management system, and at
            other times as specified in the description of an
            attribute using this type.  If such other times can
            occur, for example, the creation of a class
            instance that contains an attribute of type Counter32
            at times other than re-initialization, then
            a corresponding attribute should be defined, with an

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            appropriate type, to indicate the last discontinuity.
            Examples of appropriate types include: TimeStamp32,
            TimeStamp64, DateAndTime, TimeTicks32 or TimeTicks64
            (other types defined in this module).

            The value of the access statement for attributes with
            a type value of Counter64 should be either `readonly'
            or `eventonly'.

            A default statement should not be used for attributes
            with a type value of Counter64.";
        reference
           "RFC 2578, Sections 2. and 7.1.10.";
    };

    typedef Opaque {
        type        OctetString;
        status      obsolete;
        description
           "******* THIS TYPE DEFINITION IS OBSOLETE *******

            The Opaque type is provided solely for
            backward-compatibility, and shall not be used for
            newly-defined attributes and derived types.

            The Opaque type supports the capability to pass
            arbitrary ASN.1 syntax.  A value is encoded using
            the ASN.1 Basic Encoding Rules into a string of
            octets.  This, in turn, is encoded as an
            OctetString, in effect `double-wrapping' the
            original ASN.1 value.

            Note that a conforming implementation need only be
            able to accept and recognize opaquely-encoded data.
            It need not be able to unwrap the data and then
            interpret its contents.

            A requirement on `standard' modules is that no
            attribute may have a type value of Opaque and no
            type may be derived from the Opaque type.";
        reference
           "RFC 2578, Sections 2. and 7.1.9.";
    };

    typedef IpAddress {
        type        OctetString (4);
        status      deprecated;
        description

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           "******* THIS TYPE DEFINITION IS DEPRECATED *******

            The IpAddress type represents a 32-bit Internet
            IPv4 address.  It is represented as an OctetString
            of length 4, in network byte-order.

            Note that the IpAddress type is present for
            historical reasons.";
        reference
           "RFC 2578, Sections 2. and 7.1.5.";
    };

    typedef TimeTicks32 {
        type        Unsigned32;
        description
           "The TimeTicks32 type represents a non-negative integer
            which represents the time, modulo 2^32 (4294967296
            decimal), in hundredths of a second between two epochs.
            When attributes are defined which use this type, the
            description of the attribute identifies both of the
            reference epochs.

            For example, the TimeStamp32 type (defined in this
            module) is based on the TimeTicks32 type.";
        reference
           "RFC 2578, Sections 2. and 7.1.8.";
    };

    typedef TimeTicks64 {
        type        Unsigned64;
        description
           "The TimeTicks64 type represents a non-negative integer
            which represents the time, modulo 2^64
            (18446744073709551616 decimal), in hundredths of a second
            between two epochs.  When attributes are defined which use
            this type, the description of the attribute identifies
            both of the reference epochs.

            For example, the TimeStamp64 type (defined in this
            module) is based on the TimeTicks64 type.";
    };

    typedef TimeStamp32 {
        type        TimeTicks32;
        description
           "The value of an associated TimeTicks32 attribute at
            which a specific occurrence happened.  The specific
            occurrence must be defined in the description of any

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            attribute defined using this type.  When the specific
            occurrence occurred prior to the last time the
            associated TimeTicks32 attribute was zero, then the
            TimeStamp32 value is zero.  Note that this requires all
            TimeStamp32 values to be reset to zero when the value of
            the associated TimeTicks32 attribute reaches 497+ days
            and wraps around to zero.

            The associated TimeTicks32 attribute should be specified
            in the description of any attribute using this type.
            If no TimeTicks32 attribute has been specified, the
            default scalar attribute sysUpTime is used.";
        reference
           "RFC 2579, Section 2.";
    };

    typedef TimeStamp64 {
        type        TimeTicks64;
        description
           "The value of an associated TimeTicks64 attribute at which
            a specific occurrence happened.  The specific occurrence
            must be defined in the description of any attribute
            defined using this type.  When the specific occurrence
            occurred prior to the last time the associated TimeTicks64
            attribute was zero, then the TimeStamp64 value is zero.
            The associated TimeTicks64 attribute must be specified in
            the description of any attribute using this
            type. TimeTicks32 attributes must not be used as
            associated attributes.";
    };

    typedef TimeInterval32 {
        type        Integer32 (0..2147483647);
        description
           "A period of time, measured in units of 0.01 seconds.

            The TimeInterval32 type uses Integer32 rather than
            Unsigned32 for compatibility with RFC 2579.";
        reference
           "RFC 2579, Section 2.";
    };

    typedef TimeInterval64 {
        type        Integer64;
        description
           "A period of time, measured in units of 0.01 seconds.
            Note that negative values are allowed.";
    };

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    typedef DateAndTime {
        type        OctetString (8 | 11);
        default     0x0000000000000000000000;
        format      "2d-1d-1d,1d:1d:1d.1d,1a1d:1d";
        description
           "A date-time specification.

            field  octets  contents                  range
            -----  ------  --------                  -----
             1      1-2   year*                     0..65535
             2       3    month                     1..12 | 0
             3       4    day                       1..31 | 0
             4       5    hour                      0..23
             5       6    minutes                   0..59
             6       7    seconds                   0..60
                          (use 60 for leap-second)
             7       8    deci-seconds              0..9
             8       9    direction from UTC        '+' / '-'
             9      10    hours from UTC*           0..13
            10      11    minutes from UTC          0..59

            * Notes:
            - the value of year is in big-endian encoding
            - daylight saving time in New Zealand is +13

            For example, Tuesday May 26, 1992 at 1:30:15 PM EDT would
            be displayed as:

                         1992-5-26,13:30:15.0,-4:0

            Note that if only local time is known, then timezone
            information (fields 8-10) is not present.

            The two special values of 8 or 11 zero bytes denote an
            unknown date-time specification.";
        reference
           "RFC 2579, Section 2.";
    };

    typedef TruthValue {
        type        Enumeration (true(1), false(2));
        description
           "Represents a boolean value.";
        reference
           "RFC 2579, Section 2.";
    };

    typedef PhysAddress {

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        type        OctetString;
        format      "1x:";
        description
           "Represents media- or physical-level addresses.";
        reference
           "RFC 2579, Section 2.";
    };

    typedef MacAddress {
        type        OctetString (6);
        format      "1x:";
        description
           "Represents an IEEE 802 MAC address represented in the
            `canonical' order defined by IEEE 802.1a, i.e., as if it
            were transmitted least significant bit first, even though
            802.5 (in contrast to other 802.x protocols) requires MAC
            addresses to be transmitted most significant bit first.";
        reference
           "RFC 2579, Section 2.";
    };

    // The DisplayString definition below does not impose a size
    // restriction and is thus not the same as the DisplayString
    // definition in RFC 2579. The DisplayString255 definition is
    // provided for mapping purposes.

    typedef DisplayString {
        type        OctetString;
        format      "1a";
        description
           "Represents textual information taken from the NVT ASCII
            character set, as defined in pages 4, 10-11 of RFC 854.

            To summarize RFC 854, the NVT ASCII repertoire specifies:

             - the use of character codes 0-127 (decimal)

             - the graphics characters (32-126) are interpreted as
               US ASCII

             - NUL, LF, CR, BEL, BS, HT, VT and FF have the special
               meanings specified in RFC 854

             - the other 25 codes have no standard interpretation

             - the sequence 'CR LF' means newline

             - the sequence 'CR NUL' means carriage-return

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             - an 'LF' not preceded by a 'CR' means moving to the
               same column on the next line.

             - the sequence 'CR x' for any x other than LF or NUL is
               illegal.  (Note that this also means that a string may
               end with either 'CR LF' or 'CR NUL', but not with CR.)
        ";
    };

    typedef DisplayString255 {
        type        DisplayString (0..255);
        description
           "A DisplayString with a maximum length of 255 characters.
            Any attribute defined using this syntax may not exceed 255
            characters in length.

            The DisplayString255 type has the same semantics as the
            DisplayString textual convention defined in RFC 2579.";
        reference
           "RFC 2579, Section 2.";
    };

    // The Utf8String and Utf8String255 definitions below facilitate
    // internationalization. The definition is consistent with the
    // definition of SnmpAdminString in RFC 2571.

    typedef Utf8String {
        type        OctetString;
        format      "65535t";      // is there a better way ?
        description
           "A human readable string represented using the ISO/IEC IS
            10646-1 character set, encoded as an octet string using
            the UTF-8 transformation format described in RFC 3629.

            Since additional code points are added by amendments to
            the 10646 standard from time to time, implementations must
            be prepared to encounter any code point from 0x00000000 to
            0x7fffffff.  Byte sequences that do not correspond to the
            valid UTF-8 encoding of a code point or are outside this
            range are prohibited.

            The use of control codes should be avoided. When it is
            necessary to represent a newline, the control code
            sequence CR LF should be used.

            The use of leading or trailing white space should be
            avoided.

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            For code points not directly supported by user interface
            hardware or software, an alternative means of entry and
            display, such as hexadecimal, may be provided.

            For information encoded in 7-bit US-ASCII, the UTF-8
            encoding is identical to the US-ASCII encoding.

            UTF-8 may require multiple bytes to represent a single
            character / code point; thus the length of a Utf8String in
            octets may be different from the number of characters
            encoded.  Similarly, size constraints refer to the number
            of encoded octets, not the number of characters
            represented by an encoding.";
    };

    typedef Utf8String255 {
        type        Utf8String (0..255);
        format      "255t";
        description
           "A Utf8String with a maximum length of 255 octets.  Note
            that the size of an Utf8String is measured in octets, not
            characters.";
    };

    identity null {
        description
           "An identity used to represent null pointer values.";
    };

};

Appendix B. 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 1.33 2003/10/23 19:31:55 strauss Exp $
;;
;; Copyright (C) The Internet Society (2004). All Rights Reserved.
;;

smingFile               = optsep *(moduleStatement optsep)

;;
;; Statement rules.

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;;

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)

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                              *(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 ";"

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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 ")"

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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 ")"

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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 /

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                          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.
;;

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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

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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.
;;

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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

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                       ; 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

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/

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Full Copyright Statement

   Copyright (C) The Internet Society (2004).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.

   This document and the information contained herein are provided on an
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   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
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Acknowledgement

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