Network Working Group A. Huang Feng Internet-Draft P. Francois Intended status: Standards Track INSA-Lyon Expires: 7 April 2025 K. Watsen Watsen Networks 4 October 2024 YANG Groupings for UDP Clients and UDP Servers draft-ietf-netconf-udp-client-server-04 Abstract This document defines two YANG 1.1 modules to support the configuration of UDP clients and UDP servers. 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. 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 7 April 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Huang Feng, et al. Expires 7 April 2025 [Page 1] Internet-Draft udp-client-server-grouping October 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 2. The "ietf-udp-client" Module . . . . . . . . . . . . . . . . 2 2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 3 2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 4 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 4 3. The "ietf-udp-server" Module . . . . . . . . . . . . . . . . 6 3.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 7 3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 7 3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8 4. Security Considerations . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 5.1. URI . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.2. YANG module name . . . . . . . . . . . . . . . . . . . . 11 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.1. Normative References . . . . . . . . . . . . . . . . . . 11 7.2. Informative References . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction This document defines two YANG 1.1 [RFC7950] modules to support the configuration of UDP clients and UDP servers [RFC768]. The data models defined by the these modules may be used directly (e.g., to define a specific UDP client or UDP server) or in conjunction with the configuration defined for higher level protocols that depend on UDP. 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" grouping for configuring UDP clients with remote server information. Section 2.1 provides an overview of the YANG module for configuring UDP clients. An example of usage is illustrated in Section 2.2 and Section 2.3 defines the YANG module itself. Huang Feng, et al. Expires 7 April 2025 [Page 2] Internet-Draft udp-client-server-grouping October 2024 2.1. Data Model Overview This section provides an overview of the features and groupings defined in the "ietf-udp-client" YANG module. 2.1.1. Features The "ietf-udp-client" module defines only one "feature" statements: Features: +-- local-binding-supported This "local-binding-supported" feature indicates that the client supports configuring local bindings (i.e., the local address and local port) for UDP clients. The diagram above uses syntax that is similar to but not defined in [RFC8340]. 2.1.2. The "udp-client-grouping" Grouping The following tree diagram [RFC8340] illustrates the tree structure of the "udp-client-grouping" grouping: module: ietf-udp-client grouping udp-client-grouping: +-- remote-address inet:host +-- remote-port? inet:port-number +-- local-address? inet:ip-address {local-binding-supported}? +-- local-port? inet:port-number {local-binding-supported}? Comments: * The "remote-address" node, which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a hostname. * The "remote-port" leaf 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. The SHOULD can 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. Huang Feng, et al. Expires 7 April 2025 [Page 3] Internet-Draft udp-client-server-grouping October 2024 * The "local-address" node, which is enabled by the "local-binding- supported" feature, may be configured as an IPv4 address, an IPv6 address, or a wildcard value. * The "local-port" node, which is enabled by the "local-binding- supported" feature, is not mandatory. Its default value is "0", indicating that the operating system can pick an arbitrary port number. 2.2. Example Usage This section presents an example of usage of the "udp-client- grouping" grouping. www.example.com 10000 192.0.2.2 12345 2.3. YANG Module This module imports types defined in [RFC6991]. file "ietf-udp-client@2024-10-04" 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 Huang Feng, et al. Expires 7 April 2025 [Page 4] Internet-Draft udp-client-server-grouping October 2024 "; description "Defines a generic grouping for UDP-based client applications. 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-to-be; see the RFC itself for full legal notices."; revision 2024-10-04 { description "Initial revision"; reference "RFC-to-be: YANG Groupings for UDP Clients and UDP Servers"; } feature local-binding-supported { description "Indicates that the UDP client supports configuring local bindings (i.e., the local address and local port) for UDP clients."; } grouping udp-client-grouping { description "A reusable grouping for configuring a UDP client. 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."; leaf remote-address { type inet:host; mandatory true; description Huang Feng, et al. Expires 7 April 2025 [Page 5] Internet-Draft udp-client-server-grouping October 2024 "The IP address or hostname of the remote UDP server. If a domain name is configured, then the DNS resolution should happen on each connection attempt. If the DNS resolution results in multiple IP addresses, the IP addresses are tried according to local preference order 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-supported"; 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-supported"; type inet:port-number; default "0"; description "The local port number to bind to when sending UDP messages 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" 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 and Section 3.3 defines the YANG module itself. Huang Feng, et al. Expires 7 April 2025 [Page 6] Internet-Draft udp-client-server-grouping October 2024 3.1. Data Model Overview This section provides an overview of the groupings defined in the "ietf-udp-server" module. 3.1.1. The "udp-server-grouping" Grouping The following tree diagram [RFC8340] illustrates the structure of "udp-server-grouping" grouping: module: ietf-udp-server grouping udp-server-grouping: +-- local-bind* [local-address] +-- local-address inet:ip-address +-- local-port? inet:port-number Comments: * The "local-address" node, which is mandatory, may be configured as an IPv4 address, an IPv6 address, or a wildcard value. * The "local-port" leaf 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. The SHOULD can 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" grouping. This example shows an example of a server configured for listening to an IPv4 address: 192.0.2.2 49152 Huang Feng, et al. Expires 7 April 2025 [Page 7] Internet-Draft udp-client-server-grouping October 2024 This example 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]. file "ietf-udp-server@2024-10-04.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) 2024 IETF Trust and the persons identified as authors of the code. All rights reserved. Huang Feng, et al. Expires 7 April 2025 [Page 8] Internet-Draft udp-client-server-grouping October 2024 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 2024-10-04 { description "Initial revision"; reference "RFC-to-be: YANG Groupings for UDP Clients and UDP Servers"; } grouping udp-server-grouping { description "Provides a reusable grouping for configuring a UDP server. 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 in different address families or different ports 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 messages. 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 { Huang Feng, et al. Expires 7 April 2025 [Page 9] Internet-Draft udp-client-server-grouping October 2024 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]. The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. These network management protocols are required to use a secure transport layer and mutual authentication, e.g., SSH [RFC6242] without the "none" authentication option, Transport Layer Security (TLS) [RFC8446] with mutual X.509 authentication, and HTTPS with HTTP authentication (Section 11 of [RFC9110]). 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 module defines 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., 'node-example'). 5. IANA Considerations This document describes the URIs from IETF XML Registry and the registration of a two new YANG module names Huang Feng, et al. Expires 7 April 2025 [Page 10] Internet-Draft udp-client-server-grouping October 2024 5.1. URI IANA is requested to assign two new URIs from the IETF XML Registry [RFC3688]. The following two URIs are suggested: 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: 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, . Huang Feng, et al. Expires 7 April 2025 [Page 11] Internet-Draft udp-client-server-grouping October 2024 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [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, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . Huang Feng, et al. Expires 7 April 2025 [Page 12] Internet-Draft udp-client-server-grouping October 2024 [RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, June 2022, . 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-17, 27 September 2024, . 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 7 April 2025 [Page 13]