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 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 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 Wu, et al. Expires August 28, 2020 [Page 1] Internet-Draft Factory Default Setting February 2020 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 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 Wu, et al. Expires August 28, 2020 [Page 2] Internet-Draft Factory Default Setting February 2020 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 "". 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. , , and ) are reset to the contents of . o Read-only datastores receive their content from other datastores(e.g., gets its content from ). o All data in any dynamic configuration datastores MUST be discarded. o The contents of the datastore MUST reflect the operational state of the device after applying the factory default configuration. Wu, et al. Expires August 28, 2020 [Page 3] Internet-Draft Factory Default Setting February 2020 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 and, if present, and/or and then the content of these datastores is propagated automatically to any other read only datastores, e.g., and . Wu, et al. Expires August 28, 2020 [Page 4] Internet-Draft Factory Default Setting February 2020 o Origin: This document does not define a new origin identity as it does not interact with the datastore. o Protocols: RESTCONF, NETCONF and other management protocol. o Defining YANG module: "ietf-factory-default". The contents of 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]. 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: WG List: Editor: Qin Wu Editor: Balazs Lengyel Editor: Ye Niu "; description "This module provides functionality to reset a server to its Wu, et al. Expires August 28, 2020 [Page 5] Internet-Draft Factory Default Setting February 2020 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 { Wu, et al. Expires August 28, 2020 [Page 6] Internet-Draft Factory Default Setting February 2020 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."; } } 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. Wu, et al. Expires August 28, 2020 [Page 7] Internet-Draft Factory Default Setting February 2020 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, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Wu, et al. Expires August 28, 2020 [Page 8] Internet-Draft Factory Default Setting February 2020 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [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, . [RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K., and R. Wilton, "YANG Library", RFC 8525, DOI 10.17487/RFC8525, March 2019, . 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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . 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 Wu, et al. Expires August 28, 2020 [Page 9] Internet-Draft Factory Default Setting February 2020 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. Wu, et al. Expires August 28, 2020 [Page 10] Internet-Draft Factory Default Setting February 2020 o Remove an extension to the NETCONF operation which allows it to operate on the factory-default datastore. o Add an extension to the NETCONF 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 . 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 Wu, et al. Expires August 28, 2020 [Page 11] Internet-Draft Factory Default Setting February 2020 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 Wu, et al. Expires August 28, 2020 [Page 12]