NETMOD Working Group Q. Wu
Internet-Draft Huawei
Intended status: Standards Track B. Lengyel
Expires: August 28, 2020 Ericsson Hungary
Y. Niu
Huawei
February 25, 2020
A YANG Data Model for Factory Default Settings
draft-ietf-netmod-factory-default-13
Abstract
This document defines a YANG data model to allow clients to reset a
server back to its factory default condition. It also defines a
"factory-default" datastore to allow clients to read the factory
default configuration for the device.
The YANG data model in this document conforms to the Network
Management Datastore Architecture (NMDA) defined in RFC 8342.
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
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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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 28, 2020.
Copyright Notice
Copyright (c) 2020 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
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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 . . . . . . . . . . . . . . . . . . . . . . . 2
2. Factory-Reset RPC . . . . . . . . . . . . . . . . . . . . . . 3
3. Factory-Default Datastore . . . . . . . . . . . . . . . . . . 4
4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Changes between revisions . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
This document defines a method to reset a server to its factory
default content. The reset operation may be used, e.g., when the
existing configuration has major errors so re-starting the
configuration process from scratch is the best option.
A "factory-reset" RPC is defined. When resetting a device, all
previous configuration settings will be lost and replaced by the
factory default content.
A "factory-default" read-only datastore is defined, that contains the
data to replace the contents of implemented read-write conventional
configuration datastores at reset. This datastore can also be used
in the <get-data> operation.
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
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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 candidate configuration datastore
o running configuration datastore
o intended configuration datastore
o operational state datastore
o conventional configuration datastore
o datastore schema
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 initial configuration that is used to
initialize the configuration of a server. This datastore is
referred to as "<factory-default>".
2. Factory-Reset RPC
A new "factory-reset" RPC is introduced. Upon receiving the RPC
o All supported conventional read-write configuration datastores
(i.e. <running>, <startup>, and <candidate>) are reset to the
contents of <factory-default>.
o Read-only datastores receive their content from other
datastores(e.g., <intended> gets its content from <running>).
o All data in any dynamic configuration datastores MUST be
discarded.
o The contents of the <operational> datastore MUST reflect the
operational state of the device after applying the factory default
configuration.
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In addition, the "factory-reset" RPC MUST restore non-volatile
storage to factory condition. Depending on the system, this may
entail deleting dynamically generated files, such as those containing
keys (e.g., /etc/ssl/private), certificates (e.g., /etc/ssl), logs
(e.g., /var/log), and temporary files (e.g., /tmp/*). All security
sensitive data (i.e., private keys, passwords, etc.) SHOULD be
overwritten with zeros or a pattern before deletion. The "factory-
reset" RPC MAY also be used to trigger some other resetting tasks
such as restarting the node or some of the software processes.
Note that operators should be aware that since all read-write
datastores are immediately reset to factory default, the device may
become unreachable on the network. It is important to understand how
a given vendor's device will behave after the RPC is executed.
Implementors SHOULD reboot the device or otherwise restart processes
needed to bootstrap it.
3. Factory-Default Datastore
Following the 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 initial
configuration that can be used to initialize the configuration of a
server. A device MAY implement the "factory-reset" RPC without
implementing the "factory-default" datastore, which would only
eliminate the ability to programmatically determine the factory
default configuration.
o Name: "factory-default"
o YANG modules: The factory default datastore schema MUST either be
the same as the conventional configuration datastores, or a subset
of the datastore schema for the conventional configuration
datastores.
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 specialized, dedicated operations are provided. The
datastore can be read using the standard NETCONF/RESTCONF protocol
operations. The "factory-reset" operation copies the factory
default content to <running> and, if present, <startup> and/or
<candidate> and then the content of these datastores is propagated
automatically to any other read only datastores, e.g., <intended>
and <operational>.
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o Origin: This document does not define a new origin identity as it
does not interact with the <operational> datastore.
o Protocols: RESTCONF, NETCONF and other management protocol.
o Defining YANG module: "ietf-factory-default".
The contents of <factory-default> is defined by the device vendor and
MUST persist across device restarts. If supported, the factory-
default datastore MUST be included in the list of datastores in YANG
library [RFC 8525].
4. YANG Module
This module uses the "datastore" identity [RFC8342], and the
"default-deny-all" extension statement from [RFC8341].
<CODE BEGINS> file "ietf-factory-default@2019-11-27.yang"
module ietf-factory-default {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-factory-default";
prefix fd;
import ietf-datastores {
prefix ds;
reference
"RFC 8342: Network Management Datastore Architecture (NMDA)";
}
import ietf-netconf-acm {
prefix nacm;
reference
"RFC8341: Network Configuration Access Control Model";
}
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 provides functionality to reset a server to its
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factory default configuration and, when supported, to discover
the factory default configuration contents independent of
resetting the server.
Copyright (c) 2020 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.";
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
revision 2019-11-27 {
description
"Initial revision.";
reference
"RFC XXXX: Factory default Setting";
}
feature factory-default-datastore {
description
"Indicates that the factory default configuration is
available as a datastore.";
}
rpc factory-reset {
nacm:default-deny-all;
description
"The server resets all datastores to their factory
default content and any non-volatile storage back to
factory condition, deleting all dynamically generated
files, including those containing keys, certificates,
logs, and other temporary files.
Depending on the factory default configuration, after
being reset, the device may become unreachable on the
network.";
}
identity factory-default {
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if-feature "factory-default-datastore";
base ds:datastore;
description
"This read-only datastore contains the factory default
configuration for the device used to replace the contents
of the read-write conventional configuration datastores
during a '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].
Access to the "factory-reset" RPC operation is considered sensitive
and therefore has been restricted using the "default-deny-all" access
control defined in [RFC8341].
The "factory-reset" RPC can prevent any further management of the
device if the session and client config are included in the factory
default contents.
The operational disruption caused by setting the config to factory
default contents varies greatly depending on the implementation and
current config.
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The non-volatile storage is expected to be wiped clean and reset back
to the factory default state, but there is no guarantee that the data
is wiped according to any particular data cleansing standard, and the
owner of the device MUST NOT rely on any temporary data (e.g.,
including private keys) for recovery after the factory-reset RPC has
been invoked.
7. Acknowledgements
Thanks to Juergen Schoenwaelder, Ladislav Lhotka, Alex Campbell, Joe
Clarke, Robert Wilton, Kent Watsen, Joel Jaeggli, Lou Berger, Andy
Bierman, Susan Hares for reviewing this draft and providing 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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[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>.
[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>.
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[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>.
[RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K.,
and R. Wilton, "YANG Library", RFC 8525,
DOI 10.17487/RFC8525, March 2019,
<https://www.rfc-editor.org/info/rfc8525>.
9.2. Informative References
[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>.
[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>.
[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>.
Appendix A. Changes between revisions
Editorial Note (To be removed by RFC Editor)
v12 - 13
o Address issues raised during AD review.
v11 - 12
o Fix IDnits and reference issues from Shepherd review.
v10 - 11
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o Incorporate additional Shepherd review's comments.
v09 - 10
o Incorporate Shepherd review's comments.
v08 - 09
o Provide some guideline for operators and implementor who implement
factory defaut method.
v07 - 08
o Provide clarification and recommendation on the relationship
between factory-reset RPC and reboot.
o Nits fixed based on YANG Doctor Review.
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.
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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
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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
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