Network Working Group A. Huang Feng Internet-Draft P. Francois Intended status: Standards Track INSA-Lyon Expires: 30 August 2025 K. Watsen Watsen Networks 26 February 2025 YANG Groupings for UDP Clients and UDP Servers draft-ietf-netconf-udp-client-server-06 Abstract This document defines two YANG 1.1 modules with reusable groupings for managing UDP clients and UDP servers. 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 30 August 2025. Copyright Notice Copyright (c) 2025 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 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. Huang Feng, et al. Expires 30 August 2025 [Page 1] Internet-Draft udp-client-server-grouping February 2025 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 1.2. Adherence to the NMDA . . . . . . . . . . . . . . . . . . 2 1.3. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3 2. The "ietf-udp-client" Module . . . . . . . . . . . . . . . . 3 2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 3 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 4 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 4 3. The "ietf-udp-server" Module . . . . . . . . . . . . . . . . 7 3.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 7 3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 8 3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8 4. Security Considerations . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 5.1. URI . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.2. YANG Module Name . . . . . . . . . . . . . . . . . . . . 11 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 7.1. Normative References . . . . . . . . . . . . . . . . . . 12 7.2. Informative References . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 1. Introduction This document defines two YANG 1.1 [RFC7950] modules with reusable groupings for managing UDP clients and UDP servers [RFC768]. These modules may be used directly (e.g., define a specific UDP client or UDP server) or in conjunction with the configuration defined for higher level protocols that depend on UDP. 1.1. Requirements Language 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. Adherence to the NMDA This document is compliant with the Network Management Datastore Architecture (NMDA) [RFC8342]. It does not define any protocol accessible nodes that are "config false". Huang Feng, et al. Expires 30 August 2025 [Page 2] Internet-Draft udp-client-server-grouping February 2025 1.3. Conventions Various examples in this document use the XML [W3C.REC-xml-20081126] encoding. Other encodings, such as JSON [RFC8259], could alternatively be used. 2. The "ietf-udp-client" Module This section defines a YANG 1.1 module called "ietf-udp-client". This YANG module defines the "udp-client" grouping for providing UDP clients with remote server information. Section 2.1 provides the overview of the YANG module. An example of usage is illustrated in Section 2.2, while Section 2.3 defines the YANG module itself. 2.1. Data Model Overview This section provides an overview of the features and the grouping defined in the "ietf-udp-client" YANG module. 2.1.1. Features The "ietf-udp-client" module defines the following "feature" statement: Features: +-- local-binding This feature indicates that the client supports configuring local bindings (i.e., the local address and local port number) for UDP clients. The diagram above uses syntax that is similar to but not defined in [RFC8340]. 2.1.2. The "udp-client" Grouping The following tree diagram [RFC8340] illustrates the tree structure of the "udp-client" grouping: module: ietf-udp-client grouping udp-client: +-- remote-address inet:host +-- remote-port? inet:port-number +-- local-address? inet:ip-address {local-binding}? +-- local-port? inet:port-number {local-binding}? Huang Feng, et al. Expires 30 August 2025 [Page 3] Internet-Draft udp-client-server-grouping February 2025 The description of these parameters is provided below: * The "remote-address", which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a hostname. The resolved address should be compatible with the local address family, if also provided. * The "remote-port" is defined with neither a "default" nor a "mandatory" statement. YANG modules using this grouping SHOULD refine the grouping with a "default" statement, when the port number is well-known (e.g., a port number allocated by IANA), or with a "mandatory" statement, if a port number needs to always be configured. This MAY be ignored when the port number is neither well-known nor mandatory to configure, such as might be the case when this grouping is used by another grouping. * The "local-address", which is enabled by the "local-binding" feature, may be configured as an IPv4 address, an IPv6 address, or a wildcard value. The local address must use the same address family as the configured remote address. * The "local-port", which depends on the "local-binding" feature, is not mandatory. Its default value is "0", indicating that the operating system can select an arbitrary port number. 2.2. Example Usage This section presents an example of usage of the "udp-client" grouping. www.example.com 10000 192.0.2.2 12345 2.3. YANG Module This module imports types defined in [RFC6991]. Huang Feng, et al. Expires 30 August 2025 [Page 4] Internet-Draft udp-client-server-grouping February 2025 file "ietf-udp-client@2025-02-24.yang" module ietf-udp-client { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-udp-client"; prefix udpc; import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Authors: Alex Huang Feng Pierre Francois "; description "Defines a generic grouping for UDP-based client applications. Copyright (c) 2025 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-to-be; see the RFC itself for full legal notices."; revision 2025-02-24 { description "Initial revision"; reference "RFC-to-be: YANG Groupings for UDP Clients and UDP Servers"; } feature local-binding { description "Indicates that the UDP client supports configuring local bindings (i.e., the local address and local port number) for Huang Feng, et al. Expires 30 August 2025 [Page 5] Internet-Draft udp-client-server-grouping February 2025 UDP clients."; } grouping udp-client { description "A reusable grouping for UDP clients. Note that this grouping uses fairly typical descendant node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'udp-client-parameters'). This model purposely does not do this itself so as to provide maximum flexibility to consuming models. An example is shown in section 5 of RFC6724."; leaf remote-address { type inet:host; mandatory true; description "The IP address or hostname of the remote UDP server. If a domain name is configured, then the name resolution should happen on each connection attempt, unless a previously resolved address is cached and still valid. If the name resolution results in multiple IP addresses, the IP addresses are tried until a connection has been established or until all IP addresses have failed. "; } leaf remote-port { type inet:port-number; description "The port number of the remote UDP server."; } leaf local-address { if-feature "local-binding"; type inet:ip-address; description "The local IP address to bind to when sending UDP messages to the remote server. INADDR_ANY ('0.0.0.0') or INADDR6_ANY ('0:0:0:0:0:0:0:0' a.k.a. '::') may be used so that the server can bind to any IPv4 or IPv6 address."; } leaf local-port { if-feature "local-binding"; Huang Feng, et al. Expires 30 August 2025 [Page 6] Internet-Draft udp-client-server-grouping February 2025 type inet:port-number; default "0"; description "The local port number to bind to when sending UDP datagrams to the remote server. The port number '0', which is the default value, indicates that any available local port number may be used."; } } } 3. The "ietf-udp-server" Module This section defines a YANG 1.1 module called "ietf-udp-server". This YANG module defines the "udp-server" grouping for configuring UDP servers. Section 3.1 provides an overview of the YANG module for configuring UDP servers. An example of usage is illustrated in Section 3.2 while Section 3.3 defines the YANG module itself. 3.1. Data Model Overview This section provides an overview of the grouping defined in the "ietf-udp-server" module. 3.1.1. The "udp-server" Grouping The following tree diagram [RFC8340] illustrates the structure of "udp-server" grouping: module: ietf-udp-server grouping udp-server: +-- local-bind* [local-address] +-- local-address inet:ip-address +-- local-port? inet:port-number The description of these parameters is provided below: * The "local-address", which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a wildcard value. * The "local-port" is defined with neither a "default" nor a "mandatory" statement. YANG modules using this grouping SHOULD refine the grouping with a "default" statement, when the port number is well-known (e.g., a port number allocated by IANA), or Huang Feng, et al. Expires 30 August 2025 [Page 7] Internet-Draft udp-client-server-grouping February 2025 with a "mandatory" statement, if a port number needs to always be configured. This MAY be ignored when the port number is neither well-known nor mandatory to configure, such as might be the case when this grouping is used by another grouping. 3.2. Example Usage This section presents two examples of usage of the "udp-server" grouping. This following shows an example of a server configured for listening to an IPv4 address: 192.0.2.2 49152 This following shows an example of a server configured to listen to an IPv4 and IPv6 together: 192.0.2.2 49152 2001:db8::0 49153 3.3. YANG Module The "ietf-udp-server" imports types defined in [RFC6991]. Huang Feng, et al. Expires 30 August 2025 [Page 8] Internet-Draft udp-client-server-grouping February 2025 file "ietf-udp-server@2025-02-24.yang" module ietf-udp-server { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-udp-server"; prefix udps; import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Authors: Alex Huang Feng Pierre Francois "; description "Defines a generic grouping for UDP-based server applications. Copyright (c) 2025 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-to-be; see the RFC itself for full legal notices."; revision 2025-02-24 { description "Initial revision"; reference "RFC-to-be: YANG Groupings for UDP Clients and UDP Servers"; } grouping udp-server { description "Provides a reusable grouping for configuring UDP servers. Huang Feng, et al. Expires 30 August 2025 [Page 9] Internet-Draft udp-client-server-grouping February 2025 Note that this grouping uses fairly typical descendant node names such that a stack of 'uses' statements will have name conflicts. It is intended that the consuming data model will resolve the issue (e.g., by wrapping the 'uses' statement in a container called 'udp-server-parameters'). This model purposely does not do this itself so as to provide maximum flexibility to consuming models."; list local-bind { key "local-address"; min-elements 1; description "A list of bind (listen) points for this server instance. A server instance may have multiple bind points to support, e.g., the same port number in different address families or different port numbers in the same address family."; leaf local-address { type inet:ip-address; mandatory true; description "The local IP address to listen on for incoming UDP datagrams. To configure listening on all IPv4 addresses the value must be '0.0.0.0' (INADDR_ANY). To configure listening on all IPv6 addresses the value must be '::' (INADDR6_ANY)."; } leaf local-port { type inet:port-number; description "The local port number to listen on for incoming UDP messages."; } } } } 4. Security Considerations This section uses the template described in Section 3.7 of [I-D.ietf-netmod-rfc8407bis]. Huang Feng, et al. Expires 30 August 2025 [Page 10] Internet-Draft udp-client-server-grouping February 2025 The "ietf-udp-client" and "ietf-udp-server" YANG modules defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These protocols have to use a secure transport layer (e.g., SSH [RFC6242], TLS [RFC8446], and QUIC [RFC9000]) and have to use mutual authentication. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. The YANG modules define a set of identities, types, and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the YANG module that need to be considered. Modules that use the groupings that are defined in this document should identify the corresponding security considerations. For example, reusing some of these groupings will expose privacy-related information (e.g., 'remote-address', 'remote-port', 'local-address' or 'local-port'). 5. IANA Considerations This document describes the URIs from IETF XML Registry and the registration of a two new YANG module names 5.1. URI IANA is requested to assign two new URIs from the IETF XML Registry [RFC3688]: URI: urn:ietf:params:xml:ns:yang:ietf-udp-client Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-udp-server Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. 5.2. YANG Module Name This document also requests IANA to register the following YANG modules in the YANG Module Names registry [RFC6020] within the "YANG Parameters" registry group: Huang Feng, et al. Expires 30 August 2025 [Page 11] Internet-Draft udp-client-server-grouping February 2025 name: ietf-udp-client namespace: urn:ietf:params:xml:ns:yang:ietf-udp-client prefix: udpc maintained by IANA? N reference: RFC-to-be name: ietf-udp-server namespace: urn:ietf:params:xml:ns:yang:ietf-udp-server prefix: udps maintained by IANA? N reference: RFC-to-be 6. Acknowledgements The authors would like to thank Mohamed Boucadair, Benoit Claise, Qiufang Ma and Qin Wu for their review and valuable comments. 7. References 7.1. 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, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . Huang Feng, et al. Expires 30 August 2025 [Page 12] Internet-Draft udp-client-server-grouping February 2025 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . 7.2. Informative References [I-D.ietf-netmod-rfc8407bis] Bierman, A., Boucadair, M., and Q. Wu, "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", Work in Progress, Internet-Draft, draft-ietf- netmod-rfc8407bis-22, 14 January 2025, . [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, . [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data Interchange Format", STD 90, RFC 8259, DOI 10.17487/RFC8259, December 2017, . [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, . Huang Feng, et al. Expires 30 August 2025 [Page 13] Internet-Draft udp-client-server-grouping February 2025 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Multiplexed and Secure Transport", RFC 9000, DOI 10.17487/RFC9000, May 2021, . [RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, June 2022, . [W3C.REC-xml-20081126] Bray, T., Paoli, J., Sperberg-McQueen, C.M., Maler, E., and F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth Edition)", World Wide Web Consortium Recommendation REC-xml-20081126, November 2008, . Authors' Addresses Alex Huang Feng INSA-Lyon Lyon France Email: alex.huang-feng@insa-lyon.fr Pierre Francois INSA-Lyon Lyon France Email: pierre.francois@insa-lyon.fr Kent Watsen Watsen Networks Email: kent+ietf@watsen.net Huang Feng, et al. Expires 30 August 2025 [Page 14]