NETMOD Working Group                                               Q. Wu
Internet-Draft                                                    Huawei
Intended status: Standards Track                              B. Lengyel
Expires: May 5, 20, 2020                                   Ericsson Hungary
                                                                  Y. Niu
                                                                  Huawei
                                                       November 2, 17, 2019

                        Factory Default Setting
                  draft-ietf-netmod-factory-default-06
                  draft-ietf-netmod-factory-default-07

Abstract

   This document defines a method to reset a server to its factory-
   default content.  The reset operation may be used e.g. during initial
   zero-touch configuration or used, e.g., when the
   existing configuration has major
   errors, errors so re-starting the
   configuration process from scratch is the best option.

   A new factory-reset RPC is defined.  Several methods of documenting  When resetting a datastore, all
   previous configuration settings will be lost and replaced by the
   factory-default content are specified.

   Optionally a content.

   A new optional "factory-default" read-only datastore is defined, that
   contains the data that will be copied over to the running datastore
   at reset.

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 5, 20, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   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 Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Factory-Reset RPC . . . . . . . . . . . . . . . . . . . . . .   4   3
   3.  Factory-Default Datastore . . . . . . . . . . . . . . . . . .   4
   4.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   8   7
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   8
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Appendix A.  Difference between <startup> datastore and <factory-
                default> datastore . . . . . . . . . . . . . . . . .   9
   Appendix B.  Changes between revisions  . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   This document defines a method to reset a server to its factory-
   default content.  The reset operation may be used, e.g. during
   initial zero-touch configuration [RFC8572] or e.g., when the
   existing configuration has major errors, errors so re-starting the
   configuration process from scratch is the best option.

   A factory-reset RPC is defined.  When resetting a datastore datastore, all
   previous configuration settings will be lost and replaced by the
   factory-default content.

   A new factory-reset RPC is defined.  Several methods of documenting
   the factory-default content are specified.

   Optionally a new "factory-default" read-only datastore is defined, that contains the
   data that will be copied over to all replace the contents of implemented read-write conventional
   configuration datastores at reset.  This datastore can also be used
   in <get-data> or <get-config> operations. operation.

   NETCONF defines the <delete> operation <delete-config> RPC operation, but that allows resetting only acts
   on the
   <startup> datastore and <startup-datastore>, whereas the <discard-changes> <factory-reset> RPC operation that copies
   the content of the <running> datastore into the <candidate>
   datastore.  However it is not possible to reset the running
   datastore,
   can perform additional changes to reset the candidate datastore without changing the
   running datastore or device to fully reset any dynamic datastore.

   A RESTCONF server MAY implement the above NETCONF operations, but
   that would still not allow it
   device back to reset the running configuration. a factory-default state

   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.

   The following terms are defined in [RFC8342] [RFC7950] and are not
   redefined here:

   o  server

   o  startup configuration datastore

   o  candiate  candidate configuration datastore

   o  running configuration datastore

   o  intended configuration datastore

   o  operational state datastore

   o  conventional configuration datastore

   o  RPC operation

   The following terms are defined in this document as follows:

   o  factory-default datastore: A read-only configuration datastore
      holding a preconfigured minimal initial configuration that can be
      used to initialize the configuration of a server.  The content of
      the datastore is usually static, but MAY depend on external
      factors like available HW.

2.  Factory-Reset RPC

   A new "factory-reset" RPC is introduced.  Upon receiveing receiving the RPC the
   server resets the content of all
   o  All supported conventional read-write configuration datastores
   (e.g.,<running>
      (i.e. <running>, <startup>, and <startup>) <candidate>) are all reset to their factory-default content. the
      contents of <factory-default>.

   o  Read-only datastores receive their content from other datastores
   (e.g.
      datastores(e.g. <intended> gets its content from <running>).

   Factory-default content MAY

   o  All data in any ephemeral datastores MUST be specified by one discarded.

   o  The contents of the following
   means in descending order of precedence

   1.  <factory-default> datastore, if it exists;

   2.  by vendors using a file in YANG Instance Data
       [I-D.ietf-netmod-yang-instance-file-format] format or some other
       format in vendor's website or other places where similar off-line
       documents are kept;

   3. <operational> datastore MUST be reset back to
      an appropriate factory-default state.

   In some implementation specific manner;

   For the server supporting zero touch bootstrapping mechanisms, the
   factory default configuration causes addition, the bootstrapping process to
   execute,e.g.,the server resets configuration "factory-reset" RPC MUST restore storage to device's factory
   condition, including remove log files, remove temporary files (from
   datastore or elsewhere).  It MUST also remove security credentials
   and restoring default configuration,for security settings including remove
   certificates, keys, zero passwords, etc.  The process invoked by the version of operating system software it
   is running.  In addition,the
   "factory-reset" RPC SHOULD zero/pattern-write than remove sensitive
   files such as the TLS keys, configuration stores, etc.  The "factory-
   reset" RPC MAY also be used to trigger some other restoring and resetting tasks
   such as files
   cleanup, restarting the node or some of the software processes,
   setting some security data/passwords to the default value, removing
   logs, or removing any temporary data (from datastore or elsewhere),
   etc.  When and why these tasks are triggered is not the scope of this
   document. processes.

3.  Factory-Default Datastore

   Following guidelines for defining Datastores in the appendix A of
   [RFC8342], this document introduces a new optional datastore resource
   named 'factory-default' that represents a preconfigured minimal
   initial configuration that can be used to initialize the
   configuration of a server.  A device MAY only implement the <factory-
   reset> RPC without implementing the 'factory-default' datastore,
   which make it lose the ability to see what configuration the device
   would be reset back to.

   o  Name: "factory-default"

   o  YANG modules: all

   o  YANG nodes: all "config true" data nodes

   o  Management operations: The content of the datastore is set by the
      server in an implementation dependent manner.  The content can not
      be changed by management operations via NETCONF, RESTCONF,the CLI
      etc.  unless
      etcunless specialized, dedicated operations are provided.  The
      contents of the
      datastore can be read using NETCONF <get-data> and
      <get-config> operations, and the RESTCONF standard NETCONF/RESTCONF protocol equivalents.
      operations.  The operation <factory- reset> operation copies the factory
      default content to <running> and, if present, <startup> and then
      the content of these datastores is propagated automatically to any
      other read only datastores, e.g., <intended> and <operational>.

   o  Origin: This document does not define a new origin identity as it
      does not interact with <operational> datastore.

   o  Protocols: RESTCONF, NETCONF and other management protocol.

   o  Defining YANG module: "ietf-factory-default".

   The datastore content is usually defined by the device vendor.  It is
   usually static, but MAY change e.g., depending on external factors
   like HW available or during device upgrade.

   On devices that support non-volatile storage, the

   The contents of
   <factory > <factory-default> MUST persist across device
   restarts.

4.  YANG Module

   This module imports typedefs from [RFC8342], and it references
   [RFC6421],[RFC8341].

<CODE BEGINS> file "ietf-factory-default.yang"
   module ietf-factory-default {
     yang-version 1.1;
     namespace urn:ietf:params:xml:ns:yang:ietf-factory-default; "urn:ietf:params:xml:ns:yang:ietf-factory-default";
     prefix fd;

     import ietf-netconf { prefix nc ; }
     import ietf-datastores {
       prefix ds;
     }
     import ietf-netconf-acm {
       prefix nacm;} nacm;
     }

     organization
       "IETF NETMOD (Network Modeling) Working Group";
     contact
       "WG Web:   <https://tools.ietf.org/wg/netconf/>
        WG List:  <mailto:netconf@ietf.org>

        Editor:   Qin Wu
                  <mailto:bill.wu@huawei.com>
        Editor:   Balazs Lengyel
                  <mailto:balazs.lengyel@ericsson.com>
        Editor:   Ye Niu
                  <mailto:niuye@huawei.com>";
     description
       "This module defines the
        - factory-reset RPC
        - factory-default datastore
       - an extension to the NETCONF <get-config> operation to
         allow it to operate on the factory-default datastore.
        It provides functionality to reset a server to its
        factory-default content.

        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.

        Copyright (c) 2019 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 Simplified BSD License
        set forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX;
        see the RFC itself for full legal notices.";

     revision 2019-05-03 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: Factory default Setting";
     }

     feature factory-default-as-datastore factory-default-datastore {
       description
         "Indicates that the factory default configuration is
         also
          available as a separate datastore"; datastore.";
     }

     rpc factory-reset {
       nacm:default-deny-all;
       description
         "The server resets the content of all read-write
          configuration datastores (e.g.,<running> and <startup>) (i.e.,<running> , <startup><candidate>) to
          their factory default content.";
     }

     identity factory-default {
       if-feature "factory-default-datastore";
       base ds:datastore;
       if-feature factory-default-as-datastore;
       description "The
         "This read-only datastore contains the configuration
       that  will be copied into <running> and, if present, <startup>
       .";
     }
     augment /nc:get-config/nc:input/nc:source/nc:config-source {
        if-feature factory-default-as-datastore;
        description "Allows the get-config operation data used to use
          replace the
          factory-default datastore as contents ofthe read-write conventional configuration
          datastores during a source";
        leaf factory-default {
            type empty ;
            description
              "The factory-default datastore is the source."; factory-reset RPC operation.";
     }
   }

<CODE ENDS>
5.  IANA Considerations

   This document registers one URI in the IETF XML Registry [RFC3688].
   The following registration has been made:

      URI: urn:ietf:params:xml:ns:yang:ietf-factory-default

      Registrant Contact: The IESG.

      XML: N/A, the requested URI is an XML namespace.

   This document registers one YANG module in the YANG Module Names
   Registry [RFC6020].  The following registration has been made:

      name: ietf-factory-default

      namespace: urn:ietf:params:xml:ns:yang:ietf-factory-default

      prefix: fd

      RFC: xxxx

6.  Security Considerations

   The YANG module defined in this document extends the base operations
   for NETCONF [RFC6241] and RESTCONF [RFC8040].  The lowest NETCONF
   layer is the secure transport layer, and the mandatory-to-implement
   secure transport is Secure Shell (SSH) [RFC6242].  The lowest
   RESTCONF layer is HTTPS, and the mandatory-to-implement secure
   transport is TLS [RFC8446].

   The <factory-reset> RPC operation may be considered sensitive in some
   network enviroments,e.g., remote access to reset the device or
   overwrite security sensitive information in one of the other
   datastores, e.g. running, therefore it is important to restrict
   access to this RPC using the standard access control methods.
   [RFC8341]

   The 'factory-reset' RPC can prevent any further management of the
   device if the session and client config is included in the factory-
   reset contents.

   The operational disruption caused by setting the config to factory-
   reset contents varies greatly depending on the implementation and
   current config.

7.  Acknowledgements

   Thanks to Juergen Schoenwaelder, Ladislav Lhotka, Alex Campbell, Joe
   Clarke, Robert Wilton, Kent Watsen, Joel Jaeggli, Lou Berger, Andy
   Bierman, Susan Hares to review this draft and provide important input
   to this document.

8.  Contributors

      Rohit R Ranade
      Huawei
      Email: rohitrranade@huawei.com

9.  References

9.1.  Normative References

   [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>.

   [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>.

   [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>.

9.2.  Informative References

   [I-D.ietf-netmod-yang-instance-file-format]
              Lengyel, B. and B. Claise, "YANG Instance Data File
              Format", draft-ietf-netmod-yang-instance-file-format-04
              (work in progress), August 2019.

   [RFC8572]  Watsen, K., Farrer, I., and M. Abrahamsson, "Secure Zero
              Touch Provisioning (SZTP)", RFC 8572,
              DOI 10.17487/RFC8572, April 2019,
              <https://www.rfc-editor.org/info/rfc8572>.

Appendix A.  Difference between <startup> datastore and <factory-
             default> datastore

   When the device first boots up, the content of the <startup> and
   <factory-default> will be identical.  The content of <startup> can be
   subsequently changed by using <startup> as a target in a <copy-
   config> operation.  The <factory-default> is a read-only datastore
   and it is usually static as described in earlier sections.

Appendix B.  Changes between revisions

   Editorial Note (To be removed by RFC Editor)

   v06 - 07

   o  Remove Factory-default content specification;

   o  Remove reference to YANG instance data file format and zero touch
      provision [RFC8573];

   o  Remove copy-config operation extension on factory-default
      datastore

   v05 - 06

   o  Additional text to enhance security section.

   o  Add nacm:default-deny-all on "factory-reset" RPC.

   o  A few clarification on Factory-default content specification.

   v03 - 04

   o  Additional text to clarify factory-reset RPC usage.

   v02 - 03

   o  Update security consideration section.

   v01 - v02

   o  Address security issue in the security consideration section.

   o  Remove an extension to the NETCONF <copy-config> operation which
      allows it to operate on the factory-default datastore.

   o  Add an extension to the NETCONF <get-config> operation which
      allows it to operate on the factory-default datastore.

   v00 - v01

   o  Change YANG server into server defined in NMDA architecture based
      on discussion.

   o  Allow reset the content of all read-write configuraton datastores
      to its factory-default content except <candidate>.

   o  Add clarification text on factory-reset protocol operation
      behavior.

   v03 - v00

   o  Change draft name from draft-wu to draft-ietf-netmod-factory-
      default-00 without content changes.

   v02 - v03

   o  Change reset-datastore RPC into factory-reset RPC to allow reset
      the whole device with factory default content.

   o  Remove target datastore parameter from factory-reset RPC.

   o  Other editorial changes.

   v01 - v02

   o  Add copy-config based on Rob's comment.

   o  Reference Update.

   v03 - v00 - v01

   o  Changed name from draft-wu-netconf-restconf-factory-restore to
      draft-wu-netmod-factory-default

   o  Removed copy-config ; reset-datastore is enough

   v02 - v03

   o  Restructured

   o  Made new datastore optional

   o  Removed Netconf capability
   o  Listed Open issues

   v01 - v02

   o  -

   v00 - v01

   o  -

Authors' Addresses

   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: bill.wu@huawei.com

   Balazs Lengyel
   Ericsson Hungary
   Magyar Tudosok korutja 11
   1117 Budapest
   Hungary

   Phone: +36-70-330-7909
   Email: balazs.lengyel@ericsson.com

   Ye Niu
   Huawei

   Email: niuye@huawei.com