Skip to main content

NETCONF Extensions to Support List Pagination
draft-ietf-netconf-list-pagination-nc-03

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors Kent Watsen , Qin Wu , Per Andersson , Olof Hagsand , Hongwei Li
Last updated 2024-04-18 (Latest revision 2024-03-01)
Replaces draft-wwlh-netconf-list-pagination-nc
RFC stream Internet Engineering Task Force (IETF)
Formats
Reviews
Additional resources Mailing list discussion
Stream WG state In WG Last Call
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-netconf-list-pagination-nc-03
NETCONF Working Group                                          K. Watsen
Internet-Draft                                           Watsen Networks
Intended status: Standards Track                                   Q. Wu
Expires: 2 September 2024                                         Huawei
                                                            P. Andersson
                                                           Cisco Systems
                                                              O. Hagsand
                                                                   SUNET
                                                                   H. Li
                                                                     HPE
                                                            1 March 2024

             NETCONF Extensions to Support List Pagination
                draft-ietf-netconf-list-pagination-nc-03

Abstract

   This document defines a mapping of the list pagination mechanism
   defined in [I-D.ietf-netconf-list-pagination] to NETCONF [RFC6241].

   This document updates [RFC6241], to augment the <get> and <get-
   config> "rpc" statements, and [RFC8526], to augment the <get-data>
   "rpc" statement, to define input parameters necessary for list
   pagination.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on 2 September 2024.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

Watsen, et al.          Expires 2 September 2024                [Page 1]
Internet-Draft         NETCONF Pagination Support             March 2024

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Conventions . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Updates to NETCONF operations . . . . . . . . . . . . . . . .   3
     2.1.  Updates to RFC 6241 . . . . . . . . . . . . . . . . . . .   3
     2.2.  Updates to RFC 8526 . . . . . . . . . . . . . . . . . . .   3
   3.  List Pagination for NETCONF . . . . . . . . . . . . . . . . .   3
   4.  Error Reporting . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  YANG Module for List Pagination in NETCONF  . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     6.1.  The "IETF XML" Registry . . . . . . . . . . . . . . . . .   7
     6.2.  The "YANG Module Names" Registry  . . . . . . . . . . . .   8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
     7.1.  The "ietf-netconf-list-pagination" YANG Module  . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Appendix A.  Open Issues  . . . . . . . . . . . . . . . . . . . .  10
   Appendix B.  Example YANG Module  . . . . . . . . . . . . . . . .  10
   Appendix C.  Example Data Set . . . . . . . . . . . . . . . . . .  10
   Appendix D.  Example Queries  . . . . . . . . . . . . . . . . . .  10
     D.1.  List pagination with all query parameters . . . . . . . .  10
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   This document defines a mapping of the list pagination mechanism
   defined in [I-D.ietf-netconf-list-pagination] to NETCONF [RFC6241].

   This document updates [RFC6241] and [RFC8526], as described in
   Section 2.

   While the pagination mechanism defined in this document is designed
   for the NETCONF protocol [RFC6241], the augmented RPCs MAY be used by
   the RESTCONF protocol [RFC8040] if the RESTCONF server implements the
   "ietf-list-pagination-nc" module.

Watsen, et al.          Expires 2 September 2024                [Page 2]
Internet-Draft         NETCONF Pagination Support             March 2024

   The YANG data model in this document conforms to the Network
   Management Datastore Architecture defined in [RFC8342]

1.1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2.  Conventions

   Various examples in this document use "BASE64VALUE=" as a placeholder
   value for binary data that has been base64 encoded (per Section 9.8
   of [RFC7950]).  This placeholder value is used because real base64
   encoded structures are often many lines long and hence distracting to
   the example being presented.

2.  Updates to NETCONF operations

2.1.  Updates to RFC 6241

   The <get> and <get-config> rpc statements are augmented to accept
   additional input parameters, as described in Section 3.

2.2.  Updates to RFC 8526

   The <get-data> rpc statement is augmented to accept additional input
   parameters, as described in in Section 3.

3.  List Pagination for NETCONF

   In order for NETCONF to support [I-D.ietf-netconf-list-pagination],
   this document extends the operations <get>, <get-config> and <get-
   data> to include additional input parameters and output annotations.

   The updated operations accept a content filter parameter, similar to
   the "filter" parameter of <get-config>, but includes nodes for "list"
   and "leaf-list" filtering.

   The content filter parameter is used to specify the YANG list or
   leaf-list that is to be retrieved.  This must be a path expression
   used to represent a list or leaf-list data node.

   The following tree diagram [RFC8340] illustrates the "ietf-netconf-
   list-pagination" module:

Watsen, et al.          Expires 2 September 2024                [Page 3]
Internet-Draft         NETCONF Pagination Support             March 2024

   module: ietf-list-pagination-nc

     augment /nc:get/nc:input:
       +---w list-pagination
          +---w where?           union
          +---w sort-by?         union
          +---w locale?          string
          +---w direction?       enumeration
          +---w cursor?          string
          +---w offset?          uint32
          +---w limit?           union
          +---w sublist-limit?   union
     augment /nc:get-config/nc:input:
       +---w list-pagination
          +---w where?           union
          +---w sort-by?         union
          +---w locale?          string
          +---w direction?       enumeration
          +---w cursor?          string
          +---w offset?          uint32
          +---w limit?           union
          +---w sublist-limit?   union
     augment /ncds:get-data/ncds:input:
       +---w list-pagination
          +---w where?           union
          +---w sort-by?         union
          +---w locale?          string
          +---w direction?       enumeration
          +---w cursor?          string
          +---w offset?          uint32
          +---w limit?           union
          +---w sublist-limit?   union

   Comments:

   *  This module augments three NETCONF "rpc" statements: get, get-
      config, and get-data.

   *  The "get" and "get-config" augments are against the YANG module
      defined in [RFC6241].  The "get-data" augment is against the YANG
      module defined in [RFC8526].

Watsen, et al.          Expires 2 September 2024                [Page 4]
Internet-Draft         NETCONF Pagination Support             March 2024

4.  Error Reporting

   When an input query parameter is supplied with an erroneous value, an
   <rpc-error> MUST be returned containing the error-type value
   "application", the error-tag value "invalid-value", and MAY include
   the error-severity value "error".  Additionally the error-app-tag
   SHOULD be set containing query parameter specific error value.

4.1.  The "offset" Query Parameter

   If the "offset" query parameter value supplied is larger then the
   number of instances in the list or leaf-list target resource, the
   <rpc-error> MUST contain error-app-tag with value "offset-out-of-
   range".

5.  YANG Module for List Pagination in NETCONF

   The "ietf-netconf-list-pagination-nc" module defines conceptual
   definitions within groupings, which are not meant to be implemented
   as datastore contents by a server.

   This module has normative references to [RFC6241], [RFC6243],
   [RFC6991], and [RFC8342].

   <CODE BEGINS> file "ietf-list-pagination-nc@2024-03-01.yang"

   module ietf-list-pagination-nc {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-list-pagination-nc";
     prefix lpgnc;

     import ietf-netconf {
       prefix nc;
       reference
         "RFC 6241: Network Configuration Protocol (NETCONF)";
     }

     import ietf-netconf-nmda {
       prefix ncds;
       reference
         "RFC 8526: NETCONF Extensions to Support the
                    Network Management Datastore Architecture";
     }

     import ietf-list-pagination {
       prefix lpg;
       reference
         "RFC XXXX: List Pagination for YANG-driven Protocols";

Watsen, et al.          Expires 2 September 2024                [Page 5]
Internet-Draft         NETCONF Pagination Support             March 2024

     }

     organization
       "IETF NETCONF (Network Configuration) Working Group";

     contact
         "WG Web:   https://datatracker.ietf.org/wg/netconf
          WG List:  NETCONF WG list <mailto:netconf@ietf.org>";

     description
       "This module augments the <get>, <get-config>, and <get-data>
        'rpc' statements to support list pagination.

        Copyright (c) 2024 IETF Trust and the persons identified
        as authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with
        or without modification, is permitted pursuant to, and
        subject to the license terms contained in, the Revised
        BSD License set forth in Section 4.c of the IETF Trust's
        Legal Provisions Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC
        itself for full legal notices.

        The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
        'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
        'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document
        are to be interpreted as described in BCP 14 (RFC 2119)
        (RFC 8174) when, and only when, they appear in all
        capitals, as shown here.";

     revision 2024-03-01 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: NETCONF Extensions to Support List Pagination";
     }

     grouping pagination-parameters {
       description "A grouping for list pagination parameters.";
       container list-pagination {
         description "List pagination parameters.";
         uses lpg:where-param-grouping;
         uses lpg:sort-by-param-grouping;
         uses lpg:locale-param-grouping;

Watsen, et al.          Expires 2 September 2024                [Page 6]
Internet-Draft         NETCONF Pagination Support             March 2024

         uses lpg:direction-param-grouping;
         uses lpg:cursor-param-grouping;
         uses lpg:offset-param-grouping;
         uses lpg:limit-param-grouping;
         uses lpg:sublist-limit-param-grouping;
       }
     }

     augment "/nc:get/nc:input" {
       description
         "Allow the 'get' operation to use content filter
          parameter for specifying the YANG list or leaf-list
          that is to be retrieved";
       uses pagination-parameters;
     }

     augment "/nc:get-config/nc:input" {
       description
         "Allow the 'get-config' operation to use content filter
          parameter for specifying the YANG list or leaf-list
          that is to be retrieved";
       uses pagination-parameters;
     }

     augment "/ncds:get-data/ncds:input" {
       description
         "Allow the 'get-data' operation to use content filter
          parameter for specifying the YANG list or leaf-list
          that is to be retrieved";
       uses pagination-parameters;
     }
   }

   <CODE ENDS>

6.  IANA Considerations

6.1.  The "IETF XML" Registry

   This document registers one URI in the "ns" subregistry of the IETF
   XML Registry [RFC3688] maintained at
   https://www.iana.org/assignments/xml-registry/xml-registry.xhtml#ns.
   Following the format in [RFC3688], the following registration is
   requested:

   URI: urn:ietf:params:xml:ns:yang:ietf-list-pagination-nc
   Registrant Contact: The IESG.
   XML: N/A, the requested URI is an XML namespace.

Watsen, et al.          Expires 2 September 2024                [Page 7]
Internet-Draft         NETCONF Pagination Support             March 2024

6.2.  The "YANG Module Names" Registry

   This document registers one YANG module in the YANG Module Names
   registry [RFC6020] maintained at https://www.iana.org/assignments/
   yang-parameters/yang-parameters.xhtml.  Following the format defined
   in [RFC6020], the below registration is requested:

   name: ietf-list-pagination-nc
   namespace: urn:ietf:params:xml:ns:yang:ietf-list-pagination-nc
   prefix: pgnc
   RFC: XXXX

7.  Security Considerations

7.1.  The "ietf-netconf-list-pagination" YANG Module

   The YANG module defined in this document extends the base operations
   for NETCONF [RFC6241].  The lowest NETCONF layer is the secure
   transport layer, and the mandatory-to-implement secure transport is
   Secure Shell (SSH) [RFC6242].

   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF users to
   a preconfigured subset of all available NETCONF protocol operations
   and content.

   The security considerations for the base NETCONF protocol operations
   (see Section 9 of [RFC6241] and Section 6 of [RFC8526]) apply to the
   extension of operations <get>, <get-config>, and <get-data> defined
   in this document.

8.  References

8.1.  Normative References

   [I-D.ietf-netconf-list-pagination]
              Watsen, K., Wu, Q., Andersson, P., Hagsand, O., and H. Li,
              "List Pagination for YANG-driven Protocols", Work in
              Progress, Internet-Draft, draft-ietf-netconf-list-
              pagination-03, 1 March 2024,
              <https://datatracker.ietf.org/api/v1/doc/document/draft-
              ietf-netconf-list-pagination/>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

Watsen, et al.          Expires 2 September 2024                [Page 8]
Internet-Draft         NETCONF Pagination Support             March 2024

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6243]  Bierman, A. and B. Lengyel, "With-defaults Capability for
              NETCONF", RFC 6243, DOI 10.17487/RFC6243, June 2011,
              <https://www.rfc-editor.org/info/rfc6243>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8407]  Bierman, A., "Guidelines for Authors and Reviewers of
              Documents Containing YANG Data Models", BCP 216, RFC 8407,
              DOI 10.17487/RFC8407, October 2018,
              <https://www.rfc-editor.org/info/rfc8407>.

Watsen, et al.          Expires 2 September 2024                [Page 9]
Internet-Draft         NETCONF Pagination Support             March 2024

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8526]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "NETCONF Extensions to Support the Network
              Management Datastore Architecture", RFC 8526,
              DOI 10.17487/RFC8526, March 2019,
              <https://www.rfc-editor.org/info/rfc8526>.

8.2.  Informative References

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Appendix A.  Open Issues

   Cursors (i.e.,stable result sets) are related to the topic of dynamic
   changing lists between two queries.  How cursors can be supported
   using "feature"?

Appendix B.  Example YANG Module

   The examples within this document use the "example-social" YANG
   module defined in Appendix A.1 of [I-D.ietf-netconf-list-pagination].

Appendix C.  Example Data Set

   The Example Data Set used by the examples is defined in Appendix A.2
   of [I-D.ietf-netconf-list-pagination].

Appendix D.  Example Queries

D.1.  List pagination with all query parameters

   This example mimics that Appendix A.3.9 of
   [I-D.ietf-netconf-list-pagination].

Watsen, et al.          Expires 2 September 2024               [Page 10]
Internet-Draft         NETCONF Pagination Support             March 2024

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="42">
     <get-config>
       <source>
         <running/>
       </source>
       <filter type="xpath" select="/es:members/es:member"
         xmlns:es="https://example.com/ns/example-social"/>
         <list-pagination
           xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-list-paginat\
   ion">true</list-pagination>
         <where>//stats//joined[starts-with(@timestamp,'2020')]</where>
         <sort-by>timestamp</sort-by>
         <direction>backwards</direction>
         <offset>2</offset>
         <limit>2</limit>
         <sublist-limit>1</sublist-limit>
       </filter>
     </get-config>
   </rpc>

   Response from the NETCONF server:

   =============== NOTE: '\' line wrapping per RFC 8792 ================

   <lp:xml-list xmlns:lp="urn:ietf:params:xml:ns:yang:ietf-restconf-lis\
   t-pagination"
     xmlns="https://example.com/ns/example-social">
     <member lp:remaining="1">
       <member-id>eric</member-id>
       <email-address>eric@example.com</email-address>
       <password>$0$1543</password>
       <avatar>BASE64VALUE=</avatar>
       <tagline>Go to bed with dreams; wake up with a purpose.</tagline>
       <following>alice</following>
       <posts>
         <post>
           <timestamp>2020-09-17T18:02:04Z</timestamp>
           <title>Son, brother, husband, father</title>
           <body>What's your story?</body>
         </post>
       </posts>
       <favorites>
         <bits lp:remaining="2">two</bits>
       </favorites>
       <stats>
         <joined>2020-09-17T19:38:32Z</joined>

Watsen, et al.          Expires 2 September 2024               [Page 11]
Internet-Draft         NETCONF Pagination Support             March 2024

         <membership-level>pro</membership-level>
         <last-activity>2020-09-17T18:02:04Z</last-activity>
       </stats>
     </member>
     <member lp:remaining="1">
       <member-id>bob</member-id>
       <email-address>bob@example.com</email-address>
       <password>$0$1543</password>
       <avatar>BASE64VALUE=</avatar>
       <tagline>Here and now, like never before.</tagline>
       <posts>
         <post lp:remaining="2">
           <timestamp>2020-08-14T03:32:25Z</timestamp>
           <body>Just got in.</body>
         </post>
       </posts>
       <favorites>
         <decimal64-numbers lp:remaining="1">3.14159</bits>
       </favorites>
       <stats>
         <joined>2020-08-14T03:30:00Z</joined>
         <membership-level>standard</membership-level>
         <last-activity>2020-08-14T03:34:30Z</last-activity>
       </stats>
     </member>
   </lp:xml-list>

Acknowledgements

   This work has benefited from the discussions of RESTCONF resource
   collection over the years, in particular, [I-D.ietf-netconf-restconf-
   collection] which provides enhanced filtering features for the
   retrieval of data nodes with the GET method and [I-D.zheng-netconf-
   fragmentation] which document large size data handling challenge.
   The authors would like to thank the following for lively discussions
   on list:

   Andy Bierman Martin Björklund Robert Varga

Authors' Addresses

   Kent Watsen
   Watsen Networks
   Email: kent+ietf@watsen.net

   Qin Wu
   Huawei

Watsen, et al.          Expires 2 September 2024               [Page 12]
Internet-Draft         NETCONF Pagination Support             March 2024

   Email: bill.wu@huawei.com

   Per Andersson
   Cisco Systems
   Email: perander@cisco.com

   Olof Hagsand
   SUNET
   Email: olof@hagsand.se

   Hongwei Li
   HPE
   Email: flycoolman@gmail.com

Watsen, et al.          Expires 2 September 2024               [Page 13]