Babel routing protocol B. Stark Internet-Draft AT&T Intended status: Informational M. Jethanandani Expires: January 21, 2020 VMware July 20, 2019 Babel Information Model draft-ietf-babel-information-model-07 Abstract This Babel Information Model can be used to create data models under various data modeling regimes. It allows a Babel implementation (via a management protocol or interface) to report on its current state and may allow some limited configuration of protocol constants. 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 January 21, 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 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. Stark & Jethanandani Expires January 21, 2020 [Page 1] Internet-Draft Babel Information Model July 2019 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.2. Notation . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. The Information Model . . . . . . . . . . . . . . . . . . . . 7 3.1. Definition of babel-information-obj . . . . . . . . . . . 7 3.2. Definition of babel-constants-obj . . . . . . . . . . . . 9 3.3. Definition of babel-interfaces-obj . . . . . . . . . . . 9 3.4. Definition of babel-if-stats-obj . . . . . . . . . . . . 12 3.5. Definition of babel-neighbors-obj . . . . . . . . . . . . 12 3.6. Definition of babel-nbr-stats-obj . . . . . . . . . . . . 14 3.7. Definition of babel-routes-obj . . . . . . . . . . . . . 14 3.8. Definition of babel-hmac-key-sets-obj . . . . . . . . . . 16 3.9. Definition of babel-hmac-keys-obj . . . . . . . . . . . . 16 3.10. Definition of babel-dtls-cert-sets-obj . . . . . . . . . 17 3.11. Definition of babel-dtls-certs-obj . . . . . . . . . . . 17 4. Extending the Information Model . . . . . . . . . . . . . . . 18 5. Security Considerations . . . . . . . . . . . . . . . . . . . 18 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.1. Normative References . . . . . . . . . . . . . . . . . . 20 8.2. Informative References . . . . . . . . . . . . . . . . . 21 Appendix A. Open Issues . . . . . . . . . . . . . . . . . . . . 22 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 1. Introduction Babel is a loop-avoiding distance-vector routing protocol defined in [I-D.ietf-babel-rfc6126bis]. [I-D.ietf-babel-hmac] defines a security mechanism that allows Babel packets to be cryptographically authenticated, and [I-D.ietf-babel-dtls] defines a security mechanism that allows Babel packets to be encrypted. This document describes an information model for Babel (including implementations using one of these security mechanisms) that can be used to create management protocol data models (such as a NETCONF [RFC6241] YANG [RFC7950] data model). Due to the simplicity of the Babel protocol, most of the information model is focused on reporting Babel protocol operational state, and very little of that is considered mandatory to implement (contingent on a management protocol with Babel support being implemented). Some parameters may be configurable. However, it is up to the Babel implementation whether to allow any of these to be configured within its implementation. Where the implementation does not allow Stark & Jethanandani Expires January 21, 2020 [Page 2] Internet-Draft Babel Information Model July 2019 configuration of these parameters, it may still choose to expose them as read-only. The Information Model is presented using a hierarchical structure. This does not preclude a data model based on this Information Model from using a referential or other structure. 1.1. 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 [RFC2119] and updated by [RFC8174]. 1.2. Notation This document uses a programming language-like notation to define the properties of the objects of the information model. An optional property is enclosed by square brackets, [ ], and a list property is indicated by two numbers in angle brackets, , where m indicates the minimal number of list elements, and n indicates the maximum number of list elements. The symbol * for n means there are no defined limits on the number of list elements. Each parameter and object includes an indication of "ro" or "rw". "ro" means the parameter or object is read-only. "rw" means it is read-write. For an object, read-write means instances of the object can be created or deleted. If an implementation is allowed to choose to implement a "rw" parameter as read-only, this is noted in the parameter description. The object definitions use base types that are defined as follows: binary A binary string (sequence of octets). boolean A type representing a Boolean value. counter A non-negative integer that monotonically increases. Counters may have discontinuities and they are not expected to persist across restarts. datetime A type representing a date and time using the Gregorian calendar. The datetime format MUST conform to RFC 3339 [RFC3339]. ip-address A type representing an IP address. This type supports both IPv4 and IPv6 addresses. Stark & Jethanandani Expires January 21, 2020 [Page 3] Internet-Draft Babel Information Model July 2019 operation A type representing a remote procedure call or other action that can be used to manipulate data elements or system behaviors. reference A type representing a reference to another information or data model element or to some other device resource. string A type representing a human-readable string consisting of a (possibly restricted) subset of Unicode and ISO/IEC 10646 [ISO.10646] characters. uint A type representing an unsigned integer number. This information model does not define a precision. 2. Overview The Information Model is hierarchically structured as follows: +-- babel-information +-- babel-implementation-version +-- babel-enable +-- router-id +-- babel-supported-link-properties +-- self-seqno +-- babel-metric-comp-algorithms +-- babel-security-supported +-- babel-hmac-algorithms +-- babel-dtls-cert-types +-- babel-stats-enable +-- babel-stats-reset +-- babel-constants | +-- babel-udp-port | +-- babel-mcast-group +-- babel-interfaces | +-- babel-interface-reference | +-- babel-interface-enable | +-- babel-link-properties | +-- babel-interface-metric-algorithm | +-- babel-mcast-hello-seqno | +-- babel-mcast-hello-interval | +-- babel-update-interval | +-- babel-hmac-enable | +-- babel-if-hmac-key-sets | +-- babel-hmac-algorithm | +-- babel-hmac-verify | +-- babel-dtls-enable | +-- babel-if-dtls-cert-sets | +-- babel-dtls-cached-info Stark & Jethanandani Expires January 21, 2020 [Page 4] Internet-Draft Babel Information Model July 2019 | +-- babel-dtls-cert-prefer | +-- babel-packet-log-enable | +-- babel-packet-log | +-- babel-if-stats | | +-- babel-sent-mcast-hello | | +-- babel-sent-mcast-update | | +-- babel-received-packets | +-- babel-neighbors | | +-- babel-neighbor-address | | +-- babel-hello-mcast-history | | +-- babel-hello-ucast-history | | +-- babel-txcost | | +-- babel-exp-mcast-hello-seqno | | +-- babel-exp-ucast-hello-seqno | | +-- babel-ucast-hello-seqno | | +-- babel-ucast-hello-interval | | +-- babel-rxcost | | +-- babel-cost | | +-- babel-nbr-stats | | | +-- babel-sent-ucast-hello | | | +-- babel-sent-ucast-update | | | +-- babel-sent-IHU | | | +-- babel-received-hello | | | +-- babel-received-update | | | +-- babel-received-IHU +-- babel-routes | +-- babel-route-prefix | +-- babel-route-prefix-length | +-- babel-route-router-id | +-- babel-route-neighbor | +-- babel-route-received-metric | +-- babel-route-calculated-metric | +-- babel-route-seqno | +-- babel-route-next-hop | +-- babel-route-feasible | +-- babel-route-selected +-- babel-hmac-key-sets | +-- babel-hmac-default-apply | +-- babel-hmac-keys | | +-- babel-hmac-key-name | | +-- babel-hmac-key-use-sign | | +-- babel-hmac-key-use-verify | | +-- babel-hmac-key-value +-- babel-dtls-cert-sets | +-- babel-dtls-default-apply | +-- babel-dtls-certs | | +-- babel-cert-name | | +-- babel-cert-value Stark & Jethanandani Expires January 21, 2020 [Page 5] Internet-Draft Babel Information Model July 2019 | | +-- babel-cert-type | | +-- babel-cert-private-key | | +-- babel-cert-test Most parameters are read-only. Following is a descriptive list of the parameters that are not required to be read-only: o enable/disable Babel o create/delete babel-hmac objects o create/delete babel-dtls objects o enable/disable statistics collection o Constant: UDP port o Constant: IPv6 multicast group o Interface: Link type o Interface: enable/disable Babel on this interface o Interface: sets of HMAC keys o Interface: HMAC algorithm o Interface: verify received HMAC packets o Interface: set of DTLS certificates o Interface: use cached info extensions o Interface: preferred order of certificate types o Interface: enable/disable packet log o HMAC-keys: create/delete entries o HMAC-keys: use to sign packets o HMAC-keys: use to verify packets o DTLS-certs: create/delete entries The following parameters are required to return no value when read: o HMAC key values Stark & Jethanandani Expires January 21, 2020 [Page 6] Internet-Draft Babel Information Model July 2019 o DTLS certificate values Note that this overview is intended simply to be informative and is not normative. If there is any discrepancy between this overview and the detailed information model definitions in subsequent sections, the error is in this overview. 3. The Information Model 3.1. Definition of babel-information-obj object { string ro babel-implementation-version; boolean rw babel-enable; binary ro babel-self-router-id; string ro babel-supported-link-properties<1..*>; [uint ro babel-self-seqno;] string ro babel-metric-comp-algorithms<1..*>; string ro babel-security-supported<0..*>; [string ro babel-hmac-algorithms<1..*>;] [string ro babel-dtls-cert-types<1..*>;] [boolean rw babel-stats-enable;] [operation babel-stats-reset;] babel-constants-obj ro babel-constants; babel-interfaces-obj ro babel-interfaces<0..*>; babel-routes-obj ro babel-routes<0..*>; [babel-hmac-obj rw babel-hmac<0..*>;] [babel-dtls-obj rw babel-dtls<0..*>;] } babel-information-obj; babel-implementation-version: The name and version of this implementation of the Babel protocol. babel-enable: When written, it configures whether the protocol should be enabled (true) or disabled (false). A read from the running or intended datastore indicates the configured administrative value of whether the protocol is enabled (true) or not (false). A read from the operational datastore indicates whether the protocol is actually running (true) or not (i.e., it indicates the operational state of the protocol). A data model that does not replicate parameters for running and operational datastores can implement this as two separate parameters. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-self-router-id: The router-id used by this instance of the Babel protocol to identify itself. [I-D.ietf-babel-rfc6126bis] Stark & Jethanandani Expires January 21, 2020 [Page 7] Internet-Draft Babel Information Model July 2019 describes this as an arbitrary string of 8 octets. The router-id value MUST NOT consist of all zeroes or all ones. babel-supported-link-properties: Lists the collections of link properties supported by this instance of Babel. Valid enumeration values are defined in the Babel Link Properties registry (see Section 6). babel-self-seqno: The current sequence number included in route updates for routes originated by this node. This is a 16-bit unsigned integer. babel-metric-comp-algorithms: List of supported cost computation algorithms. Possible values include "k-out-of-j", and "ETX". babel-security-supported: List of supported security mechanisms. Possible values include "HMAC" and "DTLS". babel-hmac-algorithms: List of supported HMAC computation algorithms. Possible values include "HMAC-SHA256", "BLAKE2s". babel-dtls-cert-types: List of supported DTLS certificate types. Possible values include "X.509" and "RawPublicKey". babel-stats-enable: Indicates whether statistics collection is enabled (true) or disabled (false) on all interfaces, including neighbor-specific statistics (babel-nbr-stats). babel-stats-reset: An operation that resets all babel-if-stats and babel-nbr-stats parameters to zero. This operation has no input or output parameters. babel-constants: A babel-constants-obj object. babel-interfaces: A set of babel-interface-obj objects. babel-routes: A set of babel-route-obj objects. Contains the routes known to this node. babel-hmac: A babel-hmac-obj object. If this object is implemented, it provides access to parameters related to the HMAC security mechanism. An implementation MAY choose to expose this object as read-only ("ro"). babel-dtls: A babel-dtls-obj object. If this object is implemented, it provides access to parameters related to the DTLS security mechanism. An implementation MAY choose to expose this object as read-only ("ro"). Stark & Jethanandani Expires January 21, 2020 [Page 8] Internet-Draft Babel Information Model July 2019 3.2. Definition of babel-constants-obj object { uint rw babel-udp-port; [ip-address rw babel-mcast-group;] } babel-constants-obj; babel-udp-port: UDP port for sending and listening for Babel packets. Default is 6696. An implementation MAY choose to expose this parameter as read-only ("ro"). This is a 16-bit unsigned integer. babel-mcast-group: Multicast group for sending and listening to multicast announcements on IPv6. Default is ff02:0:0:0:0:0:1:6. An implementation MAY choose to expose this parameter as read-only ("ro"). 3.3. Definition of babel-interfaces-obj object { reference ro babel-interface-reference; [boolean rw babel-interface-enable;] string rw babel-link-properties; string ro babel-interface-metric-algorithm; [uint ro babel-mcast-hello-seqno;] [uint ro babel-mcast-hello-interval;] [uint ro babel-update-interval;] [boolean rw babel-hmac-enable;] [reference rw babel-if-hmac-key-sets<0..*>;] [string rw babel-hmac-algorithm;] [boolean rw babel-hmac-verify;] [boolean rw babel-dtls-enable;] [reference rw babel-if-dtls-cert-sets<0..*>;] [boolean rw babel-dtls-cached-info;] [string rw babel-dtls-cert-prefer<0..*>;] [boolean rw babel-packet-log-enable;] [reference ro babel-packet-log;] [babel-if-stats-obj ro babel-if-stats;] babel-neighbors-obj ro babel-neighbors<0..*>; } babel-interfaces-obj; babel-interface-reference: Reference to an IPv6 interface object as defined by the data model (e.g., YANG [RFC7950], BBF [TR-181]). Referencing syntax will be specific to the data model. If there is no set of interface objects available, this should be a string that indicates the interface name used by the underlying operating system. Stark & Jethanandani Expires January 21, 2020 [Page 9] Internet-Draft Babel Information Model July 2019 babel-interface-enable: When written, it configures whether the protocol should be enabled (true) or disabled (false) on this interface. A read from the running or intended datastore indicates the configured administrative value of whether the protocol is enabled (true) or not (false). A read from the operational datastore indicates whether the protocol is actually running (true) or not (i.e., it indicates the operational state of the protocol). A data model that does not replicate parameters for running and operational datastores can implement this as two separate parameters. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-link-properties: Indicates the properties of the link. The value MUST be one of those listed in the babel-supported-link- properties parameter. Valid enumeration values are identified in Babel Link Properties registry. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-interface-metric-algorithm: Indicates the metric computation algorithm used on this interface. The value MUST be one of those listed in the babel-information-obj babel-metric-comp-algorithms parameter. babel-mcast-hello-seqno: The current sequence number in use for multicast Hellos sent on this interface. This is a 16-bit unsigned integer. babel-mcast-hello-interval: The current interval in use for multicast Hellos sent on this interface. Units are centiseconds. This is a 16-bit unsigned integer. babel-update-interval: The current interval in use for all updates (multicast and unicast) sent on this interface. Units are centiseconds. This is a 16-bit unsigned integer. babel-hmac-enable: Indicates whether the HMAC security mechanism is enabled (true) or disabled (false). An implementation MAY choose to expose this parameter as read-only ("ro"). babel-if-hmac-keys-sets: List of references to the babel-hmac entries that apply to this interface. When an interface instance is created, all babel-hmac-key-sets instances with babel-hmac- default-apply "true" will be included in this list. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-hmac-algorithm The name of the HMAC algorithm used on this interface. The value MUST be the same as one of the enumerations Stark & Jethanandani Expires January 21, 2020 [Page 10] Internet-Draft Babel Information Model July 2019 listed in the babel-hmac-algorithms parameter. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-hmac-verify A Boolean flag indicating whether HMAC 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 HMAC hash. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-dtls-enable: Indicates whether the DTLS security mechanism is enabled (true) or disabled (false). An implementation MAY choose to expose this parameter as read-only ("ro"). babel-if-dtls-cert-sets: List of references to the babel-dtls-cert- sets entries that apply to this interface. When an interface instance is created, all babel-dtls-cert-sets instances with babel-dtls-default-apply "true" will be included in this list. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-dtls-cached-info: Indicates whether the cached_info extension is included in ClientHello and ServerHello packets. The extension is included if the value is "true". An implementation MAY choose to expose this parameter as read-only ("ro"). babel-dtls-cert-prefer: 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. babel-packet-log-enable: Indicates whether packet logging is enabled (true) or disabled (false) on this interface. babel-packet-log: 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 babel-packet-log-enable. babel-if-stats: Statistics collection object for this interface. babel-neighbors: A set of babel-neighbors-obj objects. Stark & Jethanandani Expires January 21, 2020 [Page 11] Internet-Draft Babel Information Model July 2019 3.4. Definition of babel-if-stats-obj object { uint ro babel-sent-mcast-hello; uint ro babel-sent-mcast-update; uint ro babel-received-packets; } babel-if-stats-obj; babel-sent-mcast-hello: A count of the number of multicast Hello packets sent on this interface. babel-sent-mcast-update: A count of the number of multicast update packets sent on this interface. babel-received-packets: A count of the number of Babel packets received on this interface. 3.5. Definition of babel-neighbors-obj object { ip-address ro babel-neighbor-address; [binary ro babel-hello-mcast-history;] [binary ro babel-hello-ucast-history;] uint ro babel-txcost; uint ro babel-exp-mcast-hello-seqno; uint ro babel-exp-ucast-hello-seqno; [uint ro babel-ucast-hello-seqno;] [uint ro babel-ucast-hello-interval;] [uint ro babel-rxcost;] [uint ro babel-cost;] [babel-nbr-stats-obj ro babel-nbr-stats;] } babel-neighbors-obj; babel-neighbor-address: IPv4 or IPv6 address the neighbor sends packets from. babel-hello-mcast-history: The multicast Hello history of whether or not the multicast Hello packets prior to babel-exp-mcast-hello- seqno were received. A binary sequence where the most recently received Hello is expressed as a "1" placed in the left-most bit, with prior bits shifted right (and "0" bits placed between prior Hello bits and most recent Hello for any not-received Hellos). This value should be displayed using hex digits ([0-9a-fA-F]). See [I-D.ietf-babel-rfc6126bis], section A.1. babel-hello-ucast-history: The unicast Hello history of whether or not the unicast Hello packets prior to babel-exp-ucast-hello-seqno were received. A binary sequence where the most recently received Stark & Jethanandani Expires January 21, 2020 [Page 12] Internet-Draft Babel Information Model July 2019 Hello is expressed as a "1" placed in the left-most bit, with prior bits shifted right (and "0" bits placed between prior Hello bits and most recent Hello for any not-received Hellos). This value should be displayed using hex digits ([0-9a-fA-F]). See [I-D.ietf-babel-rfc6126bis], section A.1. babel-txcost: Transmission cost value from the last IHU packet received from this neighbor, or maximum value to indicate the IHU hold timer for this neighbor has expired. See [I-D.ietf-babel-rfc6126bis], section 3.4.2. This is a 16-bit unsigned integer. babel-exp-mcast-hello-seqno: 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 0. This is a 16-bit unsigned integer. babel-exp-ucast-hello-seqno: 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. This is a 16-bit unsigned integer. babel-ucast-hello-seqno: The current sequence number in use for unicast Hellos sent to this neighbor. This is a 16-bit unsigned integer. babel-ucast-hello-interval: The current interval in use for unicast Hellos sent to this neighbor. Units are centiseconds. This is a 16-bit unsigned integer. babel-rxcost: Reception cost calculated for this neighbor. This value 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. See [I-D.ietf-babel-rfc6126bis], section 3.4.3. This is a 16-bit unsigned integer. babel-cost: 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. This is a 16-bit unsigned integer. babel-nbr-stats: Statistics collection object for this neighbor. Stark & Jethanandani Expires January 21, 2020 [Page 13] Internet-Draft Babel Information Model July 2019 3.6. Definition of babel-nbr-stats-obj object { uint ro babel-sent-ucast-hello; uint ro babel-sent-ucast-update; uint ro babel-sent-IHU; uint ro babel-received-hello; uint ro babel-received-update; uint ro babel-received-IHU; } babel-nbr-stats-obj; babel-sent-ucast-hello: A count of the number of unicast Hello packets sent to this neighbor. babel-sent-ucast-update: A count of the number of unicast update packets sent to this neighbor. babel-sent-IHU: A count of the number of IHU packets sent to this neighbor. babel-received-hello: A count of the number of Hello packets received from this neighbor. babel-received-update: A count of the number of update packets received from this neighbor. babel-received-IHU: A count of the number of IHU packets received from this neighbor. 3.7. Definition of babel-routes-obj object { ip-address ro babel-route-prefix; uint ro babel-route-prefix-length; binary ro babel-route-router-id; string ro babel-route-neighbor; uint ro babel-route-received-metric; uint ro babel-route-calculated-metric; uint ro babel-route-seqno; ip-address ro babel-route-next-hop; boolean ro babel-route-feasible; boolean ro babel-route-selected; } babel-routes-obj; babel-route-prefix: Prefix (expressed in IP address format) for which this route is advertised. Stark & Jethanandani Expires January 21, 2020 [Page 14] Internet-Draft Babel Information Model July 2019 babel-route-prefix-length: Length of the prefix for which this route is advertised. babel-route-router-id: router-id of the source router for which this route is advertised. babel-route-neighbor: Reference to the babel-neighbors entry for the neighbor that advertised this route. babel-route-received-metric: The metric with which this route was advertised by the neighbor, or maximum value to indicate the route was recently retracted and is temporarily unreachable (see Section 3.5.5 of [I-D.ietf-babel-rfc6126bis]). 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 and babel-route-received-metric MUST be non- zero. Having both be non-zero is expected for a route that is received and subsequently advertised. This is a 16-bit unsigned integer. babel-route-calculated-metric: A calculated metric for this route. How the metric is calculated is implementation-specific. Maximum value indicates the route was recently retracted and is temporarily unreachable (see Section 3.5.5 of [I-D.ietf-babel-rfc6126bis]). At least one of babel-route- calculated-metric and babel-route-received-metric MUST be non- zero. Having both be non-zero is expected for a route that is received and subsequently advertised. This is a 16-bit unsigned integer. babel-route-seqno: The sequence number with which this route was advertised. This is a 16-bit unsigned integer. babel-route-next-hop: The next-hop address of this route. This will be empty if this route has no next-hop address. babel-route-feasible: A Boolean flag indicating whether this route is feasible, as defined in Section 3.5.1 of [I-D.ietf-babel-rfc6126bis]). babel-route-selected: A Boolean flag indicating whether this route is selected (i.e., whether it is currently being used for forwarding and is being advertised). Stark & Jethanandani Expires January 21, 2020 [Page 15] Internet-Draft Babel Information Model July 2019 3.8. Definition of babel-hmac-key-sets-obj object { boolean rw babel-hmac-default-apply; babel-hmac-keys-obj rw babel-hmac-keys<0..*>; } babel-hmac-obj; babel-hmac-default-apply: A Boolean flag indicating whether this babel-hmac instance is applied to all new babel-interface instances, 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-hmac-keys list. If "false", this instance is not applied to new babel-interfaces instances when they are created. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-hmac-keys: A set of babel-hmac-keys-obj objects. 3.9. Definition of babel-hmac-keys-obj object { string rw babel-hmac-key-name; boolean rw babel-hmac-key-use-sign; boolean rw babel-hmac-key-use-verify; binary -- babel-hmac-key-value; [operation babel-hmac-key-test;] } babel-hmac-keys-obj; babel-hmac-key-name: A unique name for this HMAC 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 MUST NOT be empty and can only be provided when this instance is created (i.e., it is not subsequently writable). The value MAY be auto-generated if not explicitly supplied when the instance is created. babel-key-use-sign: 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. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-key-use-verify: 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 HMAC is computed from this key for comparing an incoming packet. An implementation MAY choose to expose this parameter as read-only ("ro"). Stark & Jethanandani Expires January 21, 2020 [Page 16] Internet-Draft Babel Information Model July 2019 babel-key-value: The value of the HMAC 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. babel-hmac-test: An operation that allows the HMAC key and hash algorithm to be tested to see if they produce an expected outcome. Input to this operation MUST be a non-empty binary string. The implementation is expected to create a hash of this string using the babel-hmac-key-value and the babel-hmac-algorithm. The output of this operation is the resulting hash, as a binary string. 3.10. Definition of babel-dtls-cert-sets-obj object { boolean rw babel-dtls-default-apply; babel-dtls-certs-obj rw babel-dtls-certs<0..*>; } babel-dtls-obj; babel-dtls-default-apply: A Boolean flag indicating whether this babel-dtls instance is applied to all new babel-interface instances, 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-dtls-certs list. If "false", this instance is not applied to new babel-interfaces instances when they are created. An implementation MAY choose to expose this parameter as read-only ("ro"). babel-dtls-certs: 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. 3.11. Definition of babel-dtls-certs-obj object { string rw babel-cert-name; string rw babel-cert-value; string rw babel-cert-type; binary -- babel-cert-private-key; [operation babel-cert-test;] } babel-dtls-certs-obj; babel-cert-name: 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 Stark & Jethanandani Expires January 21, 2020 [Page 17] Internet-Draft Babel Information Model July 2019 MUST NOT be empty and can only be provided when this instance is created (i.e., it is not subsequently writable). The value MAY be auto-generated if not explicitly supplied when the instance is created. babel-cert-value: The DTLS certificate in PEM format [RFC7468]. This value MUST be provided when this instance is created, and is not subsequently writable. babel-cert-type: 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. babel-cert-private-key: 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. babel-cert-test: An operation that allows a hash of the provided input string to be created using the certificate public key and the SHA-256 hash algorithm. Input to this operation MUST be a non-empty binary string. The output of this operation is the resulting hash, as a binary string. 4. Extending the Information Model Implementations MAY extend this information model with other parameters or objects. For example, an implementation MAY choose to expose Babel route filtering rules by adding a route filtering object with parameters appropriate to how route filtering is done in that implementation. The precise means used to extend the information model would be specific to the data model the implementation uses to expose this information. 5. Security Considerations This document defines a set of information model objects and parameters that may be exposed to be visible from other devices, and some of which may be configured. Securing access to and ensuring the integrity of this data is in scope of and the responsibility of any data model derived from this information model. Specifically, any YANG [RFC7950] data model is expected to define security exposure of the various parameters, and a [TR-181] data model will be secured by Stark & Jethanandani Expires January 21, 2020 [Page 18] Internet-Draft Babel Information Model July 2019 the mechanisms defined for the management protocol used to transport it. This information model defines objects that can allow credentials (for this device, for trusted devices, and for trusted certificate authorities) to be added and deleted. Public keys and shared secrets may be exposed through this model. This model requires that private keys never be exposed. The Babel security mechanisms that make use of these credentials (e.g., [I-D.ietf-babel-dtls], [I-D.ietf-babel-hmac]) are expected to define what credentials can be used with those mechanisms. 6. IANA Considerations This document defines a Babel Link Properties registry for the values of the babel-link-properties and babel-supported-link-properties parameters to be listed under the Babel Routing Protocol registry. Valid Babel Link Properties names are normatively defined as o MUST be at least 1 character and no more than 20 characters long o MUST contain only US-ASCII [RFC0020] letters 'A' - 'Z' and 'a' - 'z', digits '0' - '9', and hyphens ('-', ASCII 0x2D or decimal 45) o MUST contain at least one letter ('A' - 'Z' or 'a' - 'z') o MUST NOT begin or end with a hyphen o hyphens MUST NOT be adjacent to other hyphens The rules for Link Properties names, excepting the limit of 20 characters maximum, are also expressed below (as a non-normative convenience) using ABNF [RFC5234]. SRVNAME = *(1*DIGIT [HYPHEN]) ALPHA *([HYPHEN] ALNUM) ALNUM = ALPHA / DIGIT ; A-Z, a-z, 0-9 HYPHEN = %x2D ; "-" ALPHA = %x41-5A / %x61-7A ; A-Z / a-z [RFC5234] DIGIT = %x30-39 ; 0-9 [RFC5234] The allocation policy of this registry is Specification Required [RFC8126]. The initial values in the "Babel Link Properties" registry are: Stark & Jethanandani Expires January 21, 2020 [Page 19] Internet-Draft Babel Information Model July 2019 +----------+----------------------------------------+---------------+ | Name | Links Properties | Reference | +----------+----------------------------------------+---------------+ | other | implementation-specific default | (this | | | properties used | document) | | tunnel | 2-out-of-3, split horizon, RTT | (this | | | | document) | | wired | 2-out-of-3, split horizon, no RTT | (this | | | | document) | | wireless | ETX, no split horizon, no RTT | (this | | | | document) | | exp-* | Reserved for Experimental Use | (this | | | | document) | +----------+----------------------------------------+---------------+ The link properties listed are expected to include the metric computation algorithm that will be used for the link and whether split horizon optimization is used. If round trip time is used in metric computation, this should also be noted (any link property that does not mention RTT will be assumed not to use it). 7. Acknowledgements Juliusz Chroboczek, Toke Hoeiland-Joergensen, David Schinazi, Acee Lindem, and Carsten Bormann have been very helpful in refining this information model. The language in the Notation section was mostly taken from [RFC8193]. 8. References 8.1. Normative References [I-D.ietf-babel-rfc6126bis] Chroboczek, J. and D. Schinazi, "The Babel Routing Protocol", draft-ietf-babel-rfc6126bis-11 (work in progress), June 2019. [libpcap] Wireshark, "Libpcap File Format", 2015, . [RFC0020] Cerf, V., "ASCII format for network interchange", STD 80, RFC 20, DOI 10.17487/RFC0020, October 1969, . Stark & Jethanandani Expires January 21, 2020 [Page 20] Internet-Draft Babel Information Model July 2019 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7468] Josefsson, S. and S. Leonard, "Textual Encodings of PKIX, PKCS, and CMS Structures", RFC 7468, DOI 10.17487/RFC7468, April 2015, . [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 8.2. Informative References [I-D.ietf-babel-dtls] Decimo, A., Schinazi, D., and J. Chroboczek, "Babel Routing Protocol over Datagram Transport Layer Security", draft-ietf-babel-dtls-07 (work in progress), July 2019. [I-D.ietf-babel-hmac] Do, C., Kolodziejak, W., and J. Chroboczek, "HMAC authentication for the Babel routing protocol", draft- ietf-babel-hmac-08 (work in progress), July 2019. [ISO.10646] International Organization for Standardization, "Information Technology - Universal Multiple-Octet Coded Character Set (UCS)", ISO Standard 10646:2014, 2014. [RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002, . [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/RFC5234, January 2008, . [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, . Stark & Jethanandani Expires January 21, 2020 [Page 21] Internet-Draft Babel Information Model July 2019 [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8193] Burbridge, T., Eardley, P., Bagnulo, M., and J. Schoenwaelder, "Information Model for Large-Scale Measurement Platforms (LMAPs)", RFC 8193, DOI 10.17487/RFC8193, August 2017, . [TR-181] Broadband Forum, "Device Data Model", . Appendix A. Open Issues All open issues have been closed. Closed Issues: 1. See minutes of IETF 104 for discussion of issues that led to changes noted for 2019-07-08 2. HMAC spec adds other parameters to neighbor table. Check these to see if any need to be readable or writable. / None were identified. 3. Actions to add and delete HMAC and DTLS credentials, and parameters that allow credential to be identified without allowing access to private credential info. Will have separate sub-tables for HMAC and DTLS credentials. / Instead, there is a normative statement that the parameter values must never be supplied when read. 4. Consider the following statistics: under interface object: sent multicast Hello, sent updates, received Babel messages; under neighbor object: sent unicast Hello, sent updates, sent IHU, received Hello, received updates, received IHUs. Would also need to enable/disable stats and clear stats. 5. Message log (optional to implement) is still in. Support for the libpcap file format is "SHOULD". 6. Single security table with (optional) reference to interfaces that security mechanism applies to. / This actually became separate objects for DTLS and HMAC. 7. Should ABNF be normative in IANA Considerations section? Decision was to leave it as is. Stark & Jethanandani Expires January 21, 2020 [Page 22] Internet-Draft Babel Information Model July 2019 8. I want to get rid of the security log, because all Babel messages (which should be defined as all messages to/from the udp-port) are be logged by message-log. I don't like message log as it is. I think if logging is enabled it should just write to a text file. This will mean there also needs to be a means of downloading/reading the log file. Closed by having single log for all messages to/from udp port and log is represented by a string that can be reference to filename or some other part of the overall data model (depends on data model). 9. Check description of enable parameters to make sure ok for YANG and TR-181. Closed by updating description to be useful for YANG and TR-181, using language consistent with YANG descriptions. Done. 10. Distinguish signed and unsigned integers? All integers are unsigned and size is mentioned in description of each uint parameter. 11. Datatype of the router-id: Closed by introducing binary datatype and using that for router-id 12. babel-neighbor-address as IPv6-only: Closed by leaving as is (IPv4 and IPv6) 13. babel-implementation-version includes the name of the implementation: Closed by adding "name" to description 14. Delete external-cost?: Closed by deleting. 15. Would it be useful to define some parameters for reporting statistics or logs? [2 logs are now included. If others are needed they need to be proposed. See Open Issues for additional thoughts on logs and statistics.] 16. Closed by defining base64 type and using it for all router IDs: "babel-self-router-id: Should this be an opaque 64-bit value instead of int?" 17. Closed as "No": Do we need a registry for the supported security mechanisms? [Given the current limited set, and unlikelihood of massive expansion, I don't think so. But we can if someone wants it.] 18. This draft must be reviewed against draft-ietf-babel-rfc6126bis. [I feel like this has been adequately done, but I could be wrong.] Stark & Jethanandani Expires January 21, 2020 [Page 23] Internet-Draft Babel Information Model July 2019 19. babel-interfaces-obj: Juliusz:"This needs further discussion, I fear some of these are implementation details." [In the absence of discussion, the current model stands. Note that all but link-type and the neighbors sub-object are optional. If an implementation does not have any of the optional elements then it simply doesn't have them and that's fine.] 20. Would it be useful to define some parameters specifically for security anomalies? [The 2 logs should be useful in identifying security anomalies. If more is needed, someone needs to propose.] 21. I created a basic security model. It's useful for single (or no) active security mechanism (e.g., just HMAC, just DTLS, or neither); but not multiple active (both HMAC and DTLS -- which is not the same as HMAC of DTLS and would just mean that HMAC would be used on all unencrypted messages -- but right now the model doesn't allow for configuring HMAC of unencrypted messages for routers without DTLS, while DTLS is used if possible). OK? [No-one said otherwise.] 22. babel-external-cost may need more work. [if no comment, it will be left as is] 23. babel-hello-[mu]cast-history: the Hello history is formated as 16 bits, per A.1 of 6126bis. Is that a too implementation specific? [We also now have an optional-to-implement log of received messages, and I made these optional. So maybe this is ok?] 24. rxcost, txcost, cost: is it ok to model as integers, since 6126bis 2.1 says costs and metrics need not be integers. [I have them as integers unless someone insists on something else.] 25. For the security log, should it also log whether the credentials were considered ok? [Right now it doesn't and I think that's ok because if you log Hellos it was ok and if you don't it wasn't.] 26. Should Babel link types have an IANA registry? [Agreed to do this at IETF 102.] Appendix B. Change Log Individual Drafts: v00 2016-07-07 EBD: Initial individual draft version Stark & Jethanandani Expires January 21, 2020 [Page 24] Internet-Draft Babel Information Model July 2019 v01 2017-03-13: Addressed comments received in 2016-07-15 email from J. Chroboczek Working group drafts: v00 2017-07-03: Addressed points noted with "oops" in https://www.ietf.org/proceedings/98/slides/slides-98-babel-babel- information-model-00.pdf v01 2018-01-02: Removed item from issue list that was agreed (in Prague) not to be an issue. Added description of data types under Notation section, and used these in all data types. Added babel- security and babel-trust. v02 2018-04-05: * changed babel-version description to babel-implementation- version * replace optional babel-interface-seqno with optional babel- mcast-hello-seqno and babel-ucast-hello-seqno * replace optional babel-interface-hello-interval with optional babel-mcast-hello-interval and babel-ucast-hello-interval * remove babel-request-trigger-ack * remove "babel-router-id: router-id of the neighbor"; note that parameter had previously been removed but description had accidentally not been removed * added an optional "babel-cost" field to babel-neighbors object, since the spec does not define how exactly the cost is computed from rxcost/txcost * deleted babel-source-garbage-collection-time * change babel-lossy-link to babel-link-type and make this an enumeration; added at top level babel-supported-link-types so which are supported by this implementation can be reported * changes to babel-security-obj to allow self credentials to be one or more instances of a credential object. Allowed trusted credentials to include CA credentials; made some parameter name changes * updated references and Introduction Stark & Jethanandani Expires January 21, 2020 [Page 25] Internet-Draft Babel Information Model July 2019 * added Overview section * deleted babel-sources-obj * added feasible Boolean to routes * added section to briefly describe extending the information model. * deleted babel-route-neighbor * tried to make definition of babel-interface-reference clearer * added security and message logs v03 2018-05-31: * added reference to RFC 8174 (update to RFC 2119 on key words) * applied edits to Introduction text per Juliusz email of 2018-04-06 * Deleted sentence in definition of "int" data type that said it was also used for enumerations. Changed all enumerations to strings. The only enumerations were for link types, which are now "ethernet", "wireless", "tunnel", and "other". * deleted [ip-address babel-mcast-group-ipv4;] * babel-external-cost description changed * babel-security-self-cred: Added "any private key component of a credential MUST NOT be readable;" * hello-history parameters put recent Hello in most significant bit and length of parameter is not constrained. * babel-hello-seqno in neighbors-obj changed to babel-exp-mcast- hello-seqno and babel-exp-ucast-hello-seqno * added babel-route-neighbor back again. It was mistakenly deleted * changed babel-route-metric and babel-route-announced-metric to babel-route-received-metric and babel-route-calculated-metric * changed model of security object to put list of supported mechanisms at top level and separate security object per Stark & Jethanandani Expires January 21, 2020 [Page 26] Internet-Draft Babel Information Model July 2019 mechanism. This caused some other changes to the security object v04 2018-10-15: * changed babel-mcast-group-ipv6 to babel-mcast-group * link type parameters changed to point to newly defined registry * babel-ucast-hello-interval moved to neighbor object * babel-ucast-hello-seqno moved to neighbor object * babel-neighbor-ihu-interval deleted * in log descriptions, included statement that there SHOULD be ability to clear logs * added IANA registry for link types * added "ro" and "rw" to tables for read-write and read-only * added metric computation parameter to interface v05 2019-01-15: * security modeled with single table under information-obj and references to interfaces that instance applies to * changed int to uint because all integers in model were unsigned; added size of integer to description of each uint parameter * deleted log object and made single message log that points to file or other data model object used to maintain logs * deleted babel-credentials; there are no more "common" objects; hmac keys and DTLS certificates are more explicitly modeled * changed definition of babel-security-supported * added parameters for HMAC and DTLS * added statistics * changed all instances of "message" to "packet" v06 2019-07-08: Stark & Jethanandani Expires January 21, 2020 [Page 27] Internet-Draft Babel Information Model July 2019 * changed Link Type registry in IANA considerations to Lik Property Types * changed direction of reference for HMAC and DTLS objects to be from interface to these objects * provided DTLS certificate objects with a unique name * changed received and calculated metric descriptions to make clear that it is ok to have both * constrained interface reference to only IPv6 interfaces v07 2019-07-22: * babel-dtls-enable and babel-hmac-enable moved to interfaces and made rw * renamed babel-dtls and babel-hmac to babel-dtls-cert-sets and babel-hmac-key-sets and references to them from interfaces are babel-if-dtls-cert-sets and babel-if-hmac-key-sets * https://github.com/bhstark2/babel-information-model/issues/16 with nits * https://github.com/bhstark2/babel-information-model/issues/14 addressing parameters not allowed to be empty/null * https://github.com/bhstark2/babel-information-model/issues/18 on IANA link properties table Authors' Addresses Barbara Stark AT&T Atlanta, GA US Email: barbara.stark@att.com Mahesh Jethanandani VMware California US Email: mjethanandani@gmail.com Stark & Jethanandani Expires January 21, 2020 [Page 28]