Babel Working Group M. Jethanandani Internet-Draft VMware Intended status: Standards Track B. Stark Expires: February 23, 2020 AT&T August 22, 2019 YANG Data Model for Babel draft-ietf-babel-yang-model-03 Abstract This document defines a data model for the Babel routing protocol. The data model is defined using the YANG data modeling language. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD 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 February 23, 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 Jethanandani & Stark Expires February 23, 2020 [Page 1] Internet-Draft Babel YANG model August 2019 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. Note to RFC Editor . . . . . . . . . . . . . . . . . . . 2 1.2. Tree Diagram Annotations . . . . . . . . . . . . . . . . 3 2. Babel Module . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Information Model . . . . . . . . . . . . . . . . . . . . 3 2.2. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3 2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 5 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 3.1. URI Registrations . . . . . . . . . . . . . . . . . . . . 28 3.2. YANG Module Name Registration . . . . . . . . . . . . . . 28 4. Security Considerations . . . . . . . . . . . . . . . . . . . 28 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 30 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.1. Normative References . . . . . . . . . . . . . . . . . . 30 6.2. Informative References . . . . . . . . . . . . . . . . . 31 Appendix A. An Appendix . . . . . . . . . . . . . . . . . . . . 32 A.1. Statistics Gathering Enabled . . . . . . . . . . . . . . 32 A.2. Automatic Detection of Properties . . . . . . . . . . . . 33 A.3. Override Default Properties . . . . . . . . . . . . . . . 34 A.4. Configuring other Properties . . . . . . . . . . . . . . 36 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37 1. Introduction This document defines a data model for the Babel routing protocol [I-D.ietf-babel-rfc6126bis]. The data model is defined using YANG 1.1 [RFC7950] data modeling language and is Network Management Datastore Architecture (NDMA) [RFC8342] compatible. It is based on the Babel Information Model [I-D.ietf-babel-information-model]. 1.1. Note to RFC Editor Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements and remove this note before publication. o "XXXX" --> the assigned RFC value for this draft both in this draft and in the YANG models under the revision statement. Jethanandani & Stark Expires February 23, 2020 [Page 2] Internet-Draft Babel YANG model August 2019 o "ZZZZ" --> the assigned RFC value for Babel Information Model [I-D.ietf-babel-information-model] o Revision date in model, in the format 2019-08-22 needs to get updated with the date the draft gets approved. The date also needs to get reflected on the line with . 1.2. Tree Diagram Annotations For a reference to the annotations used in tree diagrams included in this draft, please see YANG Tree Diagrams [RFC8340]. 2. Babel Module This document defines a YANG 1.1 [RFC7950] data model for the configuration and management of Babel. The YANG module is based on the Babel Information Model [I-D.ietf-babel-information-model]. 2.1. Information Model There are a few things that should be noted between the Babel Information Model and this data module. The information model mandates the definition of some of the attributes, e.g. babel- implementation-version or the babel-self-router-id. These attributes are marked a read-only objects in the information module as well as in this data module. However, there is no way in the data module to mandate that a read-only attribute be present. It is up to the implementation of this data module to make sure that the attributes that are marked read-only and are mandatory are indeed present. 2.2. Tree Diagram The following diagram illustrates a top level hierarchy of the model. In addition to information like the version number implemented by this device, the model contains subtrees on constants, interfaces, routes and security. Jethanandani & Stark Expires February 23, 2020 [Page 3] Internet-Draft Babel YANG model August 2019 module: ietf-babel augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol: +--rw babel! +--ro version? string +--rw enable boolean +--ro router-id? binary +--ro seqno? uint16 +--ro metric-comp-algorithms* identityref +--ro security-supported* identityref +--ro mac-algorithms* identityref +--ro dtls-cert-types* identityref +--rw stats-enable? boolean +--rw constants | ... +--rw interfaces* [reference] | ... +--rw mac* [name] | ... +--rw dtls* [name] | ... +--ro routes* [prefix] ... The interfaces subtree describes attributes such as interface object that is being referenced, the type of link as enumerated by metric- algorithm and split-horizon and whether the interface is enabled or not. The constants subtree describes the UDP port used for sending and receiving Babel messages, and the multicast group used to send and receive announcements on IPv6. The routes subtree describes objects such as the prefix for which the route is advertised, a reference to the neighboring route, and next- hop address. Finally, for security two subtree are defined to contain MAC keys and DTLS certificates. The mac-key-sets subtree contains keys used with the MAC security mechanism. The boolean flag babel-mac-default-apply indicates whether the set of MAC keys is automatically applied to new interfaces. The dtls subtree contains certificates used with DTLS security mechanism. Similar to the MAC mechanism, the boolean flag babel-dtls-default-apply indicates whether the set of DTLS certificates is automatically applied to new interfaces. Jethanandani & Stark Expires February 23, 2020 [Page 4] Internet-Draft Babel YANG model August 2019 2.3. YANG Module This module augments A YANG Data Model for Interface Management [RFC8343], YANG Routing Management [RFC8349], imports definitions from Common YANG Data Types [RFC6991], and references HMAC: Keyed- Hashing for Message Authentication [RFC2104], Using HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512 [RFC4868], Datagram Transport Layer Security Version 1.2 [RFC6347], The Blake2 Cryptographic Hash and Message Authentication Code (MAC) [RFC7693], Babel Information Model [I-D.ietf-babel-information-model], and The Babel Routing Protocol [I-D.ietf-babel-rfc6126bis]. file "ietf-babel@2019-08-22.yang" module ietf-babel { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-babel"; prefix babel; import ietf-yang-types { prefix yt; reference "RFC 6991: Common YANG Data Types."; } import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types."; } import ietf-interfaces { prefix if; reference "RFC 8343: A YANG Data Model for Interface Management"; } import ietf-routing { prefix "rt"; reference "RFC 8349: YANG Routing Management"; } organization "IETF Babel routing protocol Working Group"; contact "WG Web: http://tools.ietf.org/wg/babel/ WG List: babel@ietf.org Editor: Mahesh Jethanandani Jethanandani & Stark Expires February 23, 2020 [Page 5] Internet-Draft Babel YANG model August 2019 mjethanandani@gmail.com Editor: Barbara Stark bs7652@att.com"; description "This YANG module defines a model for the Babel routing protocol. Copyright (c) 2019 IETF Trust and the persons identified as the document authors. 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 2019-08-22 { description "Initial version."; reference "RFC XXXX: Babel YANG Data Model."; } /* * Identities */ identity metric-comp-algorithms { description "Base identity from which all Babel metric comp algorithms are derived."; } identity two-out-of-three { base "metric-comp-algorithms"; description "2-out-of-3 algorithm."; } identity etx { base "metric-comp-algorithms"; description "Expected Transmission Count."; } /* * Babel security type identities Jethanandani & Stark Expires February 23, 2020 [Page 6] Internet-Draft Babel YANG model August 2019 */ identity security-supported { description "Base identity from which all Babel security types are derived."; } identity mac { base security-supported; description "Keyed MAC supported."; } identity dtls { base security-supported; description "Datagram Transport Layer Security (DTLS) supported."; reference "RFC 6347, Datagram Transport Layer Security Version 1.2."; } /* * Babel MAC algorithms identities. */ identity mac-algorithms { description "Base identity for all Babel MAC algorithms."; } identity hmac-sha256 { base mac-algorithms; description "HMAC-SHA256 algorithm supported."; reference "RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512 with IPsec."; } identity blake2s { base mac-algorithms; description "BLAKE2s algorithm supported."; reference "RFC 7693: The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC)."; } /* Jethanandani & Stark Expires February 23, 2020 [Page 7] Internet-Draft Babel YANG model August 2019 * Babel Cert Types */ identity dtls-cert-types { description "Base identity for Babel DTLS certificate types."; } identity x-509 { base dtls-cert-types; description "X.509 certificate type."; } identity raw-public-key { base dtls-cert-types; description "Raw Public Key type."; } /* * Babel routing protocol identity. */ identity babel { base "rt:routing-protocol"; description "Babel routing protocol"; } /* * Groupings */ grouping routes { list routes { key "prefix"; config false; leaf prefix { type inet:ip-prefix; description "Prefix (expressed in ip-address/prefix-length format) for which this route is advertised."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf router-id { type binary; description Jethanandani & Stark Expires February 23, 2020 [Page 8] Internet-Draft Babel YANG model August 2019 "router-id of the source router for which this route is advertised."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf neighbor { type leafref { path "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/babel/interfaces/" + "neighbor-objects/neighbor-address"; } description "Reference to the babel-neighbors entry for the neighbor that advertised this route."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf received-metric { type uint16; description "The metric with which this route was advertised by the neighbor, or maximum value (infinity) to indicate a the route was recently retracted and is temporarily unreachable. This metric will be 0 (zero) if the route was not received from a neighbor but was generated through other means. At least one of babel-route-calculated-metric or babel-route-received-metric MUST be non-NULL."; reference "RFC ZZZZ: Babel Information Model, Section 3.6, draft-ietf-babel-rfc6126bis: The Babel Routing Protocol, Section 3.5.5."; } leaf calculated-metric { type uint16; description "A calculated metric for this route. How the metric is calculated is implementation-specific. Maximum value (infinity) indicates the route was recently retracted and is temporarily unreachable. At least one of babel-route-calculated-metric or babel-route-received-metric MUST be non-NULL."; reference "RFC ZZZZ: Babel Information Model, Section 3.6, draft-ietf-babel-rfc6126bis: The Babel Routing Protocol, Jethanandani & Stark Expires February 23, 2020 [Page 9] Internet-Draft Babel YANG model August 2019 Section 3.5.5."; } leaf seqno { type uint16; description "The sequence number with which this route was advertised."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf next-hop { type inet:ip-address; description "The next-hop address of this route. This will be empty if this route has no next-hop address."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf feasible { type boolean; description "A boolean flag indicating whether this route is feasible."; reference "RFC ZZZZ: Babel Information Model, Section 3.6, draft-ietf-babel-rfc6126bis, The Babel Routing Protocol, Section 3.5.1."; } leaf selected { type boolean; description "A boolean flag indicating whether this route is selected, i.e., whether it is currently being used for forwarding and is being advertised."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } description "A set of babel-route-obj objects. Includes received and routes routes."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } description "Common grouping for routing used in RIB."; } Jethanandani & Stark Expires February 23, 2020 [Page 10] Internet-Draft Babel YANG model August 2019 /* * Data model */ augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol" { when "derived-from-or-self(rt:type, 'babel')" { description "Augmentation is valid only when the instance of routing type is of type 'babel'."; } description "Augment the routing module to support a common structure between routing protocols."; reference "YANG Routing Management, RFC 8349, Lhotka & Lindem, March 2018."; container babel { presence "A Babel container."; leaf version { type string; config false; description "The name and version of this implementation of the Babel protocol."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf enable { type boolean; mandatory true; description "When written, it configures whether the protocol should be enabled. A read from the or datastore therefore indicates the configured administrative value of whether the protocol is enabled or not. A read from the datastore indicates whether the protocol is actually running or not, i.e. it indicates the operational state of the protocol."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf router-id { Jethanandani & Stark Expires February 23, 2020 [Page 11] Internet-Draft Babel YANG model August 2019 type binary; config false; description "Every Babel speaker is assigned a router-id, which is an arbitrary string of 8 octets that is assumed to be unique across the routing domain"; reference "RFC ZZZZ: Babel Information Model, Section 3.1, draft-ietf-babel-rfc6126bis: The Babel Routing Protocol, Section 3."; } leaf seqno { type uint16; config false; description "Sequence number included in route updates for routes originated by this node."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf-list metric-comp-algorithms { type identityref { base "metric-comp-algorithms"; } config false; min-elements 1; description "List of cost compute algorithms supported by this implementation of Babel."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf-list security-supported { type identityref { base "security-supported"; } config false; min-elements 1; description "List of supported security mechanisms."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf-list mac-algorithms { Jethanandani & Stark Expires February 23, 2020 [Page 12] Internet-Draft Babel YANG model August 2019 type identityref { base mac-algorithms; } config false; description "List of supported MAC computation algorithms. Possible values include 'HMAC-SHA256', 'BLAKE2s'."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf-list dtls-cert-types { type identityref { base dtls-cert-types; } config false; description "List of supported DTLS certificate types. Possible values include 'X.509' and 'RawPublicKey'."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } leaf stats-enable { type boolean; description "Indicates whether statistics collection is enabled (true) or disabled (false) on all interfaces."; } container constants { leaf udp-port { type inet:port-number; default "6696"; description "UDP port for sending and receiving Babel messages. The default port is 6696."; reference "RFC ZZZZ: Babel Information Model, Section 3.2."; } leaf mcast-group { type inet:ip-address; default "ff02::1:6"; description "Multicast group for sending and receiving multicast announcements on IPv6."; reference Jethanandani & Stark Expires February 23, 2020 [Page 13] Internet-Draft Babel YANG model August 2019 "RFC ZZZZ: Babel Information Model, Section 3.2."; } description "Babel Constants object."; reference "RFC ZZZZ: Babel Information Model, Section 3.1."; } list interfaces { key "reference"; leaf reference { type if:interface-ref; description "References the name of the interface over which Babel packets are sent and received."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf enable { type boolean; default "true"; description "If true, babel sends and receives messages on this interface. If false, babel messages received on this interface are ignored and none are sent."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf metric-algorithm { type identityref { base metric-comp-algorithms; } mandatory true; description "Indicates the metric computation algorithm used on this interface. The value MUST be one of those listed in 'metric-comp-algorithms'."; reference "RFC ZZZZ: Babel Information Model, Section 3.X."; } leaf split-horizon { type boolean; description "Indicates whether or not the split horizon optimization Jethanandani & Stark Expires February 23, 2020 [Page 14] Internet-Draft Babel YANG model August 2019 is used when calculating metrics on this interface. A value of true indicates split horizon optimization is used."; reference "RFC ZZZZ: Babel Information Model, Section 3.X."; } leaf mcast-hello-seqno { type uint16; config false; description "The current sequence number in use for multicast hellos sent on this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf mcast-hello-interval { type uint16; units centiseconds; description "The current multicast hello interval in use for hellos sent on this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf update-interval { type uint16; units centiseconds; description "The current update interval in use for this interface. Units are centiseconds."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf mac-enable { type boolean; description "Indicates whether the MAC security mechanism is enabled (true) or disabled (false)."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf-list mac-key-sets { type leafref { Jethanandani & Stark Expires February 23, 2020 [Page 15] Internet-Draft Babel YANG model August 2019 path "../../mac/name"; } description "List of references to the babel-mac entries that apply to this interface. When an interface instance is created, all babel-mac-key-sets instances with babel-mac-default-apply 'true' will be included in this list."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf mac-verify { type boolean; description "A Boolean flag indicating whether MAC hashes in incoming Babel packets are required to be present and are verified. If this parameter is 'true', incoming packets are required to have a valid MAC hash."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf dtls-enable { type boolean; description "Indicates whether the DTLS security mechanism is enabled (true) or disabled (false)."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf-list dtls-certs { type leafref { path "../../dtls/name"; } description "List of references to the babel-dtls-cert-sets entries that apply to this interface. When an interface instance is created, all babel-dtls instances with babel-dtls-default-apply 'true' will be included in this list."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf dtls-cached-info { type boolean; Jethanandani & Stark Expires February 23, 2020 [Page 16] Internet-Draft Babel YANG model August 2019 description "Indicates whether the cached_info extension is included in ClientHello and ServerHello packets. The extension is included if the value is 'true'."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf-list dtls-cert-prefer { type leafref { path "../../dtls/certs/type"; } ordered-by user; description "List of supported certificate types, in order of preference. The values MUST be among those listed in the babel-dtls-cert-types parameter. This list is used to populate the server_certificate_type extension in a Client Hello. Values that are present in at least one instance in the babel-dtls-certs object of a referenced babel-dtls instance and that have a non-empty babel-cert-private-key will be used to populate the client_certificate_type extension in a Client Hello."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf packet-log-enable { type boolean; description "If true, logging of babel packets received on this interface is enabled; if false, babel packets are not logged."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } leaf packet-log { type inet:uri; config false; description "A reference or url link to a file that contains a timestamped log of packets received and sent on babel-udp-port on this interface. The [libpcap] file format with .pcap file extension SHOULD be supported for packet log files. Logging is enabled / disabled by packet-log-enable."; reference Jethanandani & Stark Expires February 23, 2020 [Page 17] Internet-Draft Babel YANG model August 2019 "RFC ZZZZ: Babel Information Model, Section 3.3."; } container stats { config false; leaf sent-mcast-hello { type yt:counter32; description "A count of the number of multicast Hello packets sent on this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.4."; } leaf sent-mcast-update { type yt:counter32; description "A count of the number of multicast update packets sent on this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.4."; } leaf sent-ucast-hello { type yt:counter32; description "A count of the number of unicast Hello packets sent to this neighbor."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf sent-ucast-update { type yt:counter32; description "A count of the number of unicast update packets sent to this neighbor."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; } leaf sent-ihu { type yt:counter32; description "A count of the number of IHU packets sent to this neighbor."; reference "RFC ZZZZ: Babel Information Model, Section 3.6."; Jethanandani & Stark Expires February 23, 2020 [Page 18] Internet-Draft Babel YANG model August 2019 } leaf received-packets { type yt:counter32; description "A count of the number of Babel packets received on this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.4."; } action reset { description "The information model [RFC ZZZZ] defines this reset action as a system-wide reset of Babel statistics parameters, but in YANG the reset action has to be contained in the container where the action needs to be performed."; input { leaf reset-at { type yt:date-and-time; description "The time when the reset was issued."; } } output { leaf reset-finished-at { type yt:date-and-time; description "The time when the reset finished."; } } } description "Statistics collection object for this interface."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } list neighbor-objects { key "neighbor-address"; config false; leaf neighbor-address { type inet:ip-address; description "IPv4 or v6 address the neighbor sends packets from."; reference Jethanandani & Stark Expires February 23, 2020 [Page 19] Internet-Draft Babel YANG model August 2019 "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf hello-mcast-history { type string; description "The multicast Hello history of whether or not the multicast Hello packets prior to babel-exp-mcast- hello-seqno were received, with a '1' for the most recent Hello placed in the most significant bit and prior Hellos shifted right (with '0' bits placed between prior Hellos and most recent Hello for any not-received Hellos); represented as a string using utf-8 encoded hex digits where a '1' bit = Hello received and a '0' bit = Hello not received."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf hello-ucast-history { type string; description "The unicast Hello history of whether or not the unicast Hello packets prior to babel-exp-ucast- hello-seqno were received, with a '1' for the most recent Hello placed in the most significant bit and prior Hellos shifted right (with '0' bits placed between prior Hellos and most recent Hello for any not-received Hellos); represented as a string using utf-8 encoded hex digits where a '1' bit = Hello received and a '0' bit = Hello not received."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf txcost { type int32; default "0"; description "Transmission cost value from the last IHU packet received from this neighbor, or maximum value (infinity) to indicate the IHU hold timer for this neighbor has expired description."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf exp-mcast-hello-seqno { Jethanandani & Stark Expires February 23, 2020 [Page 20] Internet-Draft Babel YANG model August 2019 type uint16; default "0"; description "Expected multicast Hello sequence number of next Hello to be received from this neighbor; if multicast Hello packets are not expected, or processing of multicast packets is not enabled, this MUST be NULL."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf exp-ucast-hello-seqno { type uint16; default "0"; description "Expected unicast Hello sequence number of next Hello to be received from this neighbor; if unicast Hello packets are not expected, or processing of unicast packets is not enabled, this MUST be NULL."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf ucast-hello-seqno { type uint16; description "Expected unicast Hello sequence number of next Hello to be received from this neighbor. If unicast Hello packets are not expected, or processing of unicast packets is not enabled, this MUST be 0."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf ucast-hello-interval { type uint16; units centiseconds; description "The current interval in use for unicast hellos sent to this neighbor. Units are centiseconds."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf rxcost { type int32; description "Reception cost calculated for this neighbor. This value Jethanandani & Stark Expires February 23, 2020 [Page 21] Internet-Draft Babel YANG model August 2019 is usually derived from the Hello history, which may be combined with other data, such as statistics maintained by the link layer. The rxcost is sent to a neighbor in each IHU."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } leaf cost { type int32; description "Link cost is computed from the values maintained in the neighbor table. The statistics kept in the neighbor table about the reception of Hellos, and the txcost computed from received IHU packets."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } description "A set of Babel Neighbor Object."; reference "RFC ZZZZ: Babel Information Model, Section 3.5."; } description "A set of Babel Interface objects."; reference "RFC ZZZZ: Babel Information Model, Section 3.3."; } list mac { key "name"; leaf name { type string; description "A string that uniquely identifies the mac object."; } leaf default-apply { type boolean; description "A Boolean flag indicating whether this babel-mac instance is applied to all new interfaces, by default. If 'true', this instance is applied to new babel-interfaces instances at the time they are created, by including it in the babel-interface-mac-keys list. If 'false', this instance is not applied to new babel-interfaces instances when they are created."; Jethanandani & Stark Expires February 23, 2020 [Page 22] Internet-Draft Babel YANG model August 2019 reference "RFC ZZZZ: Babel Information Model, Section 3.7."; } list keys { key "name"; min-elements "1"; leaf name { type string; mandatory true; description "A unique name for this MAC key that can be used to identify the key in this object instance, since the key value is not allowed to be read. This value can only be provided when this instance is created, and is not subsequently writable."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } leaf use-sign { type boolean; mandatory true; description "Indicates whether this key value is used to sign sent Babel packets. Sent packets are signed using this key if the value is 'true'. If the value is 'false', this key is not used to sign sent Babel packets."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } leaf use-verify { type boolean; mandatory true; description "Indicates whether this key value is used to verify incoming Babel packets. This key is used to verify incoming packets if the value is 'true'. If the value is 'false', no MAC is computed from this key for comparing an incoming packet."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } leaf value { type binary; Jethanandani & Stark Expires February 23, 2020 [Page 23] Internet-Draft Babel YANG model August 2019 mandatory true; description "The value of the MAC key. An implementation MUST NOT allow this parameter to be read. This can be done by always providing an empty string, or through permissions, or other means. This value MUST be provided when this instance is created, and is not subsequently writable. This value is of a length suitable for the associated babel-mac-key-algorithm. If the algorithm is based on the HMAC construction [RFC2104], the length MUST be between 0 and the block size of the underlying hash inclusive (where 'HMAC-SHA256' block size is 64 bytes as described in [RFC4868]). If the algorithm is 'BLAKE2s', the length MUST be between 0 and 32 bytes inclusive, as described in [RFC7693]."; reference "RFC ZZZZ: Babel Information Model, Section 3.8, RFC 2104: HMAC: Keyed-Hashing for Message Authentication RFC 4868: Using HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512 with IPsec, RFC 7693: The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC)."; } leaf algorithm { type identityref { base mac-algorithms; } description "The name of the MAC algorithm used with this key. The value MUST be the same as one of the enumerations listed in the babel-mac-algorithms parameter."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } action test { input { leaf test-string { type binary; mandatory true; description "The test string on which this test has to be performed."; } Jethanandani & Stark Expires February 23, 2020 [Page 24] Internet-Draft Babel YANG model August 2019 } output { leaf resulting-hash { type binary; mandatory true; description "An operation that allows the MAC key and hash algorithm to be tested to see if they produce an expected outcome. Input to this operation is a binary string. The implementation is expected to create a hash of this string using the babel-mac-key-value and the babel-mac-algorithm. The output of this operation is the resulting hash, as a binary string."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } } } description "A set of babel-mac-keys-obj objects."; reference "RFC ZZZZ: Babel Information Model, Section 3.8."; } description "A babel-mac-obj object. If this object is implemented, it provides access to parameters related to the MAC security mechanism."; reference "RFC ZZZZ: Babel Information Model, Section 3.7."; } list dtls { key "name"; leaf name { type string; description "A string that uniquely identifies a dtls object."; } leaf default-apply { type boolean; mandatory true; description "A Boolean flag indicating whether this babel-dtls instance is applied to all new interfaces, by default. If 'true', this instance is applied to new babel-interfaces Jethanandani & Stark Expires February 23, 2020 [Page 25] Internet-Draft Babel YANG model August 2019 instances at the time they are created, by including it in the babel-interface-dtls-certs list. If 'false', this instance is not applied to new babel-interfaces instances when they are created."; reference "RFC ZZZZ: Babel Information Model, Section 3.9."; } list certs { key "name"; min-elements "1"; leaf name { type string; description "A unique name for this DTLS certificate that can be used to identify the certificate in this object instance, since the value is too long to be useful for identification. This value MUST NOT be empty and can only be provided when this instance is created (i.e., it is not subsequently writable)."; reference "RFC ZZZZ: Babel Information Model, Section 3.10."; } leaf value { type string; mandatory true; description "The DTLS certificate in PEM format [RFC7468]. This value can only be provided when this instance is created, and is not subsequently writable."; reference "RFC ZZZZ: Babel Information Model, Section 3.10."; } leaf type { type identityref { base dtls-cert-types; } mandatory true; description "The name of the certificate type of this object instance. The value MUST be the same as one of the enumerations listed in the babel-dtls-cert-types parameter. This value can only be provided when this instance is created, and is not subsequently writable."; reference Jethanandani & Stark Expires February 23, 2020 [Page 26] Internet-Draft Babel YANG model August 2019 "RFC ZZZZ: Babel Information Model, Section 3.10."; } leaf private-key { type binary; mandatory true; description "The value of the private key. If this is non-empty, this certificate can be used by this implementation to provide a certificate during DTLS handshaking. An implementation MUST NOT allow this parameter to be read. This can be done by always providing an empty string, or through permissions, or other means. This value can only be provided when this instance is created, and is not subsequently writable."; reference "RFC ZZZZ: Babel Information Model, Section 3.10."; } action test { input { leaf test-string { type binary; mandatory true; description "The test string on which this test has to be performed."; } } output { leaf resulting-hash { type binary; mandatory true; description "The output of this operation is a binary string, and is the resulting hash computed using the certificate public key, and the SHA-256 hash algorithm."; } } } description "A set of babel-dtls-keys-obj objects. This contains both certificates for this implementation to present for authentication, and to accept from others. Certificates with a non-empty babel-cert-private-key can be presented by this implementation for authentication."; Jethanandani & Stark Expires February 23, 2020 [Page 27] Internet-Draft Babel YANG model August 2019 reference "RFC ZZZZ: Babel Information Model, Section 3.10."; } description "A babel-dtls-obj object. If this object is implemented, it provides access to parameters related to the DTLS security mechanism."; reference "RFC ZZZZ: Babel Information Model, Section 3.9"; } description "Babel Information Objects."; reference "RFC ZZZZ: Babel Information Model, Section 3."; uses routes; } } } 3. IANA Considerations This document registers one URIs and one YANG module. 3.1. URI Registrations URI: urn:ietf:params:xml:ns:yang:ietf-babel 3.2. YANG Module Name Registration This document registers one YANG module in the YANG Module Names registry YANG [RFC6020]. Name:ietf-babel Namespace: urn:ietf:params:xml:ns:yang:ietf-babel prefix: babel reference: RFC XXXX 4. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocol such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. Jethanandani & Stark Expires February 23, 2020 [Page 28] Internet-Draft Babel YANG model August 2019 The NETCONF Access Control Model (NACM [RFC8341]) provides the means to restrict access for particular NETCONF users to a pre-configured subset of all available NETCONF protocol operations and content. There are a number of data nodes defined in the YANG module which are writable/created/deleted (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., ) to these data nodes without proper protection can have a negative effect on network operations.These are the subtrees and data nodes and their sensitivity/vulnerability from a config true perspective: babel: This container includes an "enable" parameter that can be used to enable or disable use of Babel on a router babel/constants: This container includes configuration parameters that can prevent reachability if misconfigured. babel/interfaces: This leaf-list has configuration parameters that can enable/disable security mechanisms and change performance characteristics of the Babel protocol. babel/hmac and babel/dtls: These contain security credentials that influence whether packets are trusted. Some of the readable data or config false nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability from a config false perpective: babel: Access to the information in the various nodes can disclose the network topology. Additionally, the routes used by a network device may be used to mount a subsequent attack on traffic traversing the network device. babel/hmac and babel/dtls: These contain security credentials, include private credentials of the router. Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability from a RPC operation perspective: Jethanandani & Stark Expires February 23, 2020 [Page 29] Internet-Draft Babel YANG model August 2019 babel/hmac/hmac/keys/test and babel/dtls/certs/test: These can be used in a brute force attack to identify the credentials being used to secure the Babel protocol. 5. Acknowledgements Juliusz Chroboczek provided most of the example configurations for babel that are shown in the Appendix. 6. References 6.1. Normative References [I-D.ietf-babel-rfc6126bis] Chroboczek, J. and D. Schinazi, "The Babel Routing Protocol", draft-ietf-babel-rfc6126bis-14 (work in progress), August 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA- 384, and HMAC-SHA-512 with IPsec", RFC 4868, DOI 10.17487/RFC4868, May 2007, . [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, January 2012, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [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, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . Jethanandani & Stark Expires February 23, 2020 [Page 30] Internet-Draft Babel YANG model August 2019 [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for Routing Management (NMDA Version)", RFC 8349, DOI 10.17487/RFC8349, March 2018, . 6.2. Informative References [I-D.ietf-babel-information-model] Stark, B. and M. Jethanandani, "Babel Information Model", draft-ietf-babel-information-model-08 (work in progress), August 2019. [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- Hashing for Message Authentication", RFC 2104, DOI 10.17487/RFC2104, February 1997, . [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, . [RFC7693] Saarinen, M-J., Ed. and J-P. Aumasson, "The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC)", RFC 7693, DOI 10.17487/RFC7693, November 2015, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 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, . Jethanandani & Stark Expires February 23, 2020 [Page 31] Internet-Draft Babel YANG model August 2019 [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . Appendix A. An Appendix This section is devoted to examples that demonstrate how Babel can be configured. A.1. Statistics Gathering Enabled In this example, interface eth0 is being configured for routing protocol Babel, and statistics gathering is enabled. Jethanandani & Stark Expires February 23, 2020 [Page 32] Internet-Draft Babel YANG model August 2019 eth0 ianaift:ethernetCsmacd true babel:babel name:babel true eth0 two-out-of-three true true A.2. Automatic Detection of Properties eth0 ianaift:ethernetCsmacd true wlan0 ianaift:ieee80211 true babel:babel name:babel true eth0 true two-out-of-three true wlan0 true etx false A.3. Override Default Properties eth0 ianaift:ethernetCsmacd true eth1 ianaift:ethernetCsmacd true tun0 ianaift:tunnel true babel:babel name:babel true eth0 true two-out-of-three true Jethanandani & Stark Expires February 23, 2020 [Page 35] Internet-Draft Babel YANG model August 2019 eth1 true etx false tun0 true two-out-of-three true A.4. Configuring other Properties eth0 ianaift:ethernetCsmacd true ppp0 ianaift:ppp true Jethanandani & Stark Expires February 23, 2020 [Page 36] Internet-Draft Babel YANG model August 2019 babel:babel name:babel true eth0 true two-out-of-three true ppp0 true 30 120 two-out-of-three Authors' Addresses Mahesh Jethanandani VMware California USA Email: mjethanandani@gmail.com Barbara Stark AT&T Atlanta, GA USA Email: barbara.stark@att.com Jethanandani & Stark Expires February 23, 2020 [Page 37]