| Network Working Group | M. Bjorklund |
| Internet-Draft | Tail-f Systems |
| Updates: 6241, 7950 (if approved) | J. Schoenwaelder |
| Intended status: Standards Track | Jacobs University |
| Expires: November 28, 2018 | P. Shafer |
| K. Watsen | |
| Juniper Networks | |
| R. Wilton | |
| Cisco Systems | |
| May 27, 2018 |
NETCONF Extensions to Support the Network Management Datastore Architecture
draft-ietf-netconf-nmda-netconf-06
This document extends the NETCONF protocol defined in RFC 6241 in order to support the Network Management Datastore Architecture defined in RFC 8342.
This document updates both RFC 6241 and RFC 7950. The update to RFC 6241 adds new operations <get‑data> and <edit‑data>, and augments existing operations <lock>, <unlock>, and <validate>. The update to RFC 7950 requires the usage of I-D.ietf-netconf-rfc7895bis by NETCONF servers implementing the Network Management Datastore Architecture.
RFC Ed.: Please replace "I‑D.ietf‑netconf‑rfc7895bis" above with its final RFC assignment and remove this note.
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 November 28, 2018.
Copyright (c) 2018 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.
This document extends the NETCONF protocol defined in [RFC6241] in order to support the Network Management Datastore Architecture (NMDA) defined in [RFC8342].
This document updates [RFC6241] in order to enable NETCONF clients to interact with all the datastores supported by a server implementing the NMDA. The update both adds new operations <get‑data> and <edit‑data>, and augments existing operations <lock>, <unlock>, and <validate>.
This document also updates [RFC7950] in order to enable NETCONF clients to both discover which datastores are supported by the NETCONF server, as well as determine which modules are supported in each datastore. The update requires NETCONF servers implementing the NMDA to support [I-D.ietf-netconf-rfc7895bis].
This document uses the terminology defined by the NMDA [RFC8342].
The following term is defined in [I-D.ietf-netconf-rfc7895bis]:
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
Tree diagrams used in this document follow the notation defined in [RFC8340].
RFC Ed.: Update 201X-XX-XX below with correct date.
An NMDA-compliant NETCONF server MUST support the operational state datastore and it MUST implement at least revision 201X-XX-XX of the "ietf‑yang‑library" module defined in [I-D.ietf-netconf-rfc7895bis].
A NETCONF client can discover which datastores and YANG modules the server supports by reading the YANG library information from the operational state datastore.
The server MUST advertise the following capability in the <hello> message (line breaks and whitespaces are used for formatting reasons only):
urn:ietf:params:netconf:capability:yang-library:1.1?
revision=<date>&checksum=<checksum-value>
The parameter "revision" has the same value as the revision date of the "ietf‑yang‑library" module implemented by the server. This parameter MUST be present.
The parameter "checksum" contains the YANG library checksum [I-D.ietf-netconf-rfc7895bis]. This parameter MUST be present.
With this mechanism, a client can cache the supported datastores and YANG modules for a server and only update the cache if the "checksum" value in the <hello> message changes.
This document updates [RFC7950], Section 5.6.4, to allow servers to advertise the capability :yang-library:1.1 instead of :yang-library:1.0, and to implement the subtree "/yang‑library" [I-D.ietf-netconf-rfc7895bis] instead of "/modules‑state".
This section describes the NETCONF extensions needed to support the NMDA. These changes are defined in a new YANG ([RFC7950]) module "ietf‑netconf‑nmda".
These changes include the use of source and target parameters based on the "datastore" identity defined in the "ietf‑datastores" module [RFC8342]. The use of identities allows future expansion in a way that the choice-based strategy from the original operations (e.g., <get‑config>, <edit‑config>) does not.
Two new operations <get‑data> and <edit‑data> are defined in this document in order to support the NMDA. These operations are similar to the <get‑config> and <edit‑config> operations but they can work on an extensible set of datastores.
The <get‑data> operation retrieves data from a specific NMDA datastore. This operation is similar to NETCONF's <get‑config> operation defined in [RFC6241], but it adds the flexibility to select the source datastore.
+---x get-data
+---w input
| +---w datastore ds:datastore-ref
| +---w (filter-spec)?
| | +--:(subtree-filter)
| | | +---w subtree-filter? <anydata>
| | +--:(xpath-filter)
| | +---w xpath-filter? yang:xpath1.0 {nc:xpath}?
| +---w config-filter? boolean
| +---w (origin-filters)? {origin}?
| | +--:(origin-filter)
| | | +---w origin-filter* or:origin-ref
| | +--:(negated-origin-filter)
| | +---w negated-origin-filter* or:origin-ref
| +---w max-depth? union
| +---w with-origin? empty {origin}?
| +---w with-defaults? with-defaults-mode
+--ro output
+--ro data? <anydata>
The "datastore" parameter indicates the datastore which is the source of the data to be retrieved. This is a datastore identity.
The <get‑data> operation accepts a content filter parameter, similar to the "filter" parameter of <get‑config>, but using explicit nodes for subtree filtering ("subtree‑filter") and XPath filtering ("xpath‑filter").
The "config‑filter" parameter can be used to retrieve only "config true" or "config false" nodes.
The "origin‑filter" parameter, which can be present multiple times, selects nodes matching any of the given values. The "negated‑origin‑filter", which can be present multiple times, selects nodes that do not match all given values. The "origin‑filter" and "negated‑origin‑filter" parameters cannot be used together.
The "max‑depth" parameter can be used by the client to limit the number of sub-tree levels that are returned in the reply.
If the "with‑defaults" capability is supported by the server, then the "with‑defaults" parameter, defined in [RFC6243], is supported for <get‑data> operations that target conventional configuration datastores.
The "with‑defaults" parameter is optional to support for <get‑data> operations that target <operational>. The associated capability to indicate a server's support is identified with the URI:
urn:ietf:params:netconf:capability:with-operational-defaults:1.0
If the "with‑defaults" parameter is supported for <get‑data> operations on <operational>, then all retrieval modes specified in either the 'basic‑mode' or 'also‑supported' parameters of the "with‑defaults" capability are permitted. The behavior of the "with‑defaults" parameter for <operational> is defined as below:
Support for "with‑defaults" in <get‑data> operations on any datastore not defined in [RFC8342] SHOULD be defined by the specification for the datastore.
The <get‑data> operation defines a parameter named "with‑origin", which if present, requests that the server includes "origin" metadata annotations in its response, as detailed in the NMDA. This parameter is only valid for the operational state datastore and any datastores with identities derived from the "operational" identity. Otherwise, if an invalid datastore is specified then an error is returned, as specified in "ietf‑netconf‑nmda" (see Section 4). Note that "origin" metadata annotations are not included in a response unless a client explicitly requests them.
Data in the operational state datastore can come from multiple sources. The server should return the most accurate value for the "origin" metadata annotation as possible, indicating the source of the operational value, as specified in Section 5.3.4 of [RFC8342].
When encoding the origin metadata annotation for a hierarchy of returned nodes, the annotation may be omitted for a child node when the value matches that of the parent node, as described in the "ietf‑origin" YANG module [RFC8342].
The "with‑origin" parameter is optional to support. It is identified with the feature "origin".
The following example shows the <get‑data> version of the <get‑config> example shown in Section 7.1 of [RFC6241].
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get-data xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-nmda"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<datastore>ds:running</datastore>
<subtree-filter>
<top xmlns="http://example.com/schema/1.2/config">
<users/>
</top>
</subtree-filter>
</get-data>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-nmda">
<top xmlns="http://example.com/schema/1.2/config">
<users>
<user>
<name>root</name>
<type>superuser</type>
<full-name>Charlie Root</full-name>
<company-info>
<dept>1</dept>
<id>1</id>
</company-info>
</user>
<!-- additional <user> elements appear here... -->
</users>
</top>
</data>
</rpc-reply>
The <edit‑data> operation changes the contents of a writable datastore, similar to the <edit‑config> operation defined in [RFC6241], but with additional flexibility in naming the target datastore. If an <edit‑data> operation is invoked on a non-writable datastore, then an error is returned, as specified in "ietf‑netconf‑nmda" (see Section 4).
+---x edit-data
+---w input
+---w datastore ds:datastore-ref
+---w default-operation? enumeration
+---w (edit-content)
+--:(config)
| +---w config? <anydata>
+--:(url)
+---w url? inet:uri {nc:url}?
The "datastore" parameter is a datastore identity that indicates the desired target datastore where changes should be made.
The "default‑operation" parameter is a copy of the "default‑operation" parameter of the <edit‑config> operation.
The "edit‑content" choice mirrors the "edit‑content" choice of the <edit‑config> operation. Note, however, that the "config" element in the "edit‑content" choice of <edit‑data> uses "anydata" (introduced in YANG 1.1) while the "config" element in the "edit‑content" choice of <edit‑config> used "anyxml".
The <edit‑data> operation does not support the "error‑option" and the "test‑option" parameters that were part of the <edit‑config> operation. The error behaviour of <edit‑data> corresponds to the "error‑option" "rollback‑on‑error".
If the "with‑defaults" capability is supported by the server, the semantics of editing modes is the same as for <edit‑config>, as described in section 4.5.2 of [RFC6243].
Semantics for "with‑defaults" in <edit‑data> operations on any non conventional configuration datastores SHOULD be defined by the specification for the datastore.
The following example shows the <edit‑data> version of the first <edit‑config> example in Section 7.2 of [RFC6241], setting the MTU to 1500 on an interface named "Ethernet0/0" in the running configuration datastore.
<rpc message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-data xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-nmda"
xmlns:ds="urn:ietf:params:xml:ns:yang:ietf-datastores">
<datastore>ds:running</datastore>
<config>
<top xmlns="http://example.com/schema/1.2/config">
<interface>
<name>Ethernet0/0</name>
<mtu>1500</mtu>
</interface>
</top>
</config>
</edit-data>
</rpc>
<rpc-reply message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
The other <edit‑config> examples shown in Section 7.2 can be translated to <edit‑data> examples in a similar way.
Several of the operations defined in the base NETCONF YANG module "ietf‑netconf" [RFC6241] may be used with new datastores. Hence, the <lock>, <unlock>, and <validate> operations are augmented with a new "datastore" leaf that can select the desired datastore. If a <lock>, <unlock>, or <validate> operation is not supported on a particular datastore then an error is returned, as specified in "ietf‑netconf‑nmda" (see Section 4).
This module imports definitions from [RFC6991], [RFC6241], [RFC6243], and [RFC8342].
RFC Ed.: update the date below with the date of RFC publication and remove this note.
<CODE BEGINS> file "ietf-netconf-nmda@2018-05-22"
module ietf-netconf-nmda {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-nmda";
prefix ncds;
import ietf-yang-types {
prefix yang;
reference "RFC 6991: Common YANG Data Types.";
}
import ietf-inet-types {
prefix inet;
reference "RFC 6991: Common YANG Data Types.";
}
import ietf-datastores {
prefix ds;
reference "RFC 8342: Network Management Datastore Architecture.";
}
import ietf-origin {
prefix or;
reference "RFC 8342: Network Management Datastore Architecture.";
}
import ietf-netconf {
prefix nc;
reference "RFC 6241: Network Configuration Protocol (NETCONF)";
}
import ietf-netconf-with-defaults {
prefix ncwd;
reference "RFC 6243: With-defaults Capability for NETCONF.";
}
organization
"IETF NETCONF Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Martin Bjorklund
<mailto:mbj@tail-f.com>
Author: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
Author: Phil Shafer
<mailto:phil@juniper.net>
Author: Kent Watsen
<mailto:kwatsen@juniper.net>
Author: Rob Wilton
<rwilton@cisco.com>";
description
"This YANG module defines a set of NETCONF operations to support
the Network Management Datastore Architecture (NMDA).
Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(http://www.rfc-editor.org/info/rfcxxxx); see the RFC itself
for full legal notices.";
// RFC Ed.: update the date below with the date of RFC publication
// and remove this note.
// RFC Ed.: replace XXXX with actual RFC number and remove this
// note.
revision 2018-05-22 {
description
"Initial revision.";
reference
"RFC XXXX: NETCONF Extensions to Support the Network Management
Datastore Architecture";
}
feature origin {
description
"Indicates that the server supports the 'origin' annotation.";
reference
"RFC 8342: Network Management Datastore Architecture";
}
feature with-defaults {
description
"NETCONF :with-defaults capability; If the server advertises
the :with-defaults capability for a session, then this
feature must also be enabled for that session. Otherwise,
this feature must not be enabled.";
reference
"RFC 6243: With-defaults Capability for NETCONF, section 4; and
RFC XXXX: NETCONF Extensions to Support the Network Management
Datastore Architecture, section 3.1.1.1.";
}
rpc get-data {
description
"Retrieve data from an NMDA datastore. The content returned
by get-data must satisfy all filters, i.e., the filter
criteria are logically ANDed.
The 'with-origin' parameter is only valid for an operational
datastore. If 'with-origin' is used with an invalid datastore,
then the server MUST return an <rpc-error> element with an
<error-tag> value of 'invalid-value'.
The 'with-defaults' parameter only applies to the operational
datastore if the NETCONF :with-defaults and
:with-operational-defaults capabilities are both advertised.
If the 'with-defaults' parameter is present in a request for
which it is not supported, then the server MUST return an
<rpc-error> element with an <error-tag> value of
'invalid-value'.";
input {
leaf datastore {
type ds:datastore-ref;
mandatory true;
description
"Datastore from which to retrieve data.
If the datastore is not supported by the server, then the
server MUST return an <rpc-error> element with an
<error-tag> value of 'invalid-value'.";
}
choice filter-spec {
description
"The content filter specification for this request.";
anydata subtree-filter {
description
"This parameter identifies the portions of the
target datastore to retrieve.";
reference
"RFC 6241: Network Configuration Protocol, Section 6.";
}
leaf xpath-filter {
if-feature nc:xpath;
type yang:xpath1.0;
description
"This parameter contains an XPath expression identifying
the portions of the target datastore to retrieve.
If the expression returns a node-set, all nodes in the
node-set are selected by the filter. Otherwise, if the
expression does not return a node-set, then the get-data
operation fails.
The expression is evaluated in the following XPath
context:
o The set of namespace declarations are those in
scope on the 'xpath-filter' leaf element.
o The set of variable bindings is empty.
o The function library is the core function library,
and the XPath functions defined in section 10 in
RFC 7950.
o The context node is the root node of the target
datastore.";
}
}
leaf config-filter {
type boolean;
description
"Filter for nodes with the given value for their
'config' property.";
}
choice origin-filters {
when 'derived-from-or-self(datastore, "ds:operational")';
if-feature origin;
description
"Filters based on the 'origin' annotation.";
leaf-list origin-filter {
type or:origin-ref;
description
"Filter based on the 'origin' annotation. A node matches
the filter if its 'origin' annotation is derived from or
equal to any of the given filter values.";
}
leaf-list negated-origin-filter {
type or:origin-ref;
description
"Filter based on the 'origin' annotation. A node matches
the filter if its 'origin' annotation is not derived
from and not equal to all of the given filter values.";
}
}
leaf max-depth {
type union {
type uint16 {
range "1..65535";
}
type enumeration {
enum "unbounded" {
description
"All descendant nodes are included.";
}
}
}
default "unbounded";
description
"For each node selected by the filter, this parameter
selects how many conceptual sub-tree levels should be
returned in the reply. If the depth is 1, the reply
includes just the selected nodes but no children. If the
depth is 'unbounded', all descendant nodes are included.";
}
leaf with-origin {
when 'derived-from-or-self(../datastore, "ds:operational")';
if-feature origin;
type empty;
description
"If this parameter is present, the server will return
the 'origin' annotation for the nodes that has one.";
}
uses ncwd:with-defaults-parameters {
if-feature with-defaults;
}
}
output {
anydata data {
description
"Copy of the source datastore subset which matched
the filter criteria (if any). An empty data
container indicates that the request did not
produce any results.";
}
}
}
rpc edit-data {
description
"Edit data in an NMDA datastore.
If an error condition occurs such that an error severity
<rpc-error> element is generated, the server will stop
processing the <edit-data> operation and restore the
specified configuration to its complete state at
the start of this <edit-data> operation.";
input {
leaf datastore {
type ds:datastore-ref;
mandatory true;
description
"Datastore which is the target of the edit-data operation.
If the target datastore is not writable, or is not
supported by the server, then the server MUST return an
<rpc-error> element with an <error-tag> value of
'invalid-value'.";
}
leaf default-operation {
type enumeration {
enum "merge" {
description
"The default operation is merge.";
}
enum "replace" {
description
"The default operation is replace.";
}
enum "none" {
description
"There is no default operation.";
}
}
default "merge";
description
"The default operation to use.";
}
choice edit-content {
mandatory true;
description
"The content for the edit operation.";
anydata config {
description
"Inline config content.";
}
leaf url {
if-feature nc:url;
type inet:uri;
description
"URL based config content.";
}
}
}
}
/*
* Augment the lock and unlock operations with a
* "datastore" parameter.
*/
augment "/nc:lock/nc:input/nc:target/nc:config-target" {
description
"Add NMDA Datastore as target.";
leaf datastore {
type ds:datastore-ref;
description
"Datastore to lock.
The lock operation is only supported on writable datastores.
If the lock operation is not supported by the server on the
specified target datastore, then the server MUST return an
<rpc-error> element with an <error-tag> value of
'invalid-value'.";
}
}
augment "/nc:unlock/nc:input/nc:target/nc:config-target" {
description
"Add NMDA Datastore as target.";
leaf datastore {
type ds:datastore-ref;
description
"Datastore to unlock.
The unlock operation is only supported on writable
datastores.
If the unlock operation is not supported by the server on
the specified target datastore, then the server MUST return
an <rpc-error> element with an <error-tag> value of
'invalid-value'.";
}
}
/*
* Augment the validate operation with a
* "datastore" parameter.
*/
augment "/nc:validate/nc:input/nc:source/nc:config-source" {
description
"Add NMDA Datastore as source.";
leaf datastore {
type ds:datastore-ref;
description
"Datastore to validate.
The validate operation is supported only on configuration
datastores.
If the validate operation is not supported by the server on
the specified target datastore, then the server MUST return
an <rpc-error> element with an <error-tag> value of
'invalid-value'.";
}
}
}
<CODE ENDS>
This document registers two capability identifier URNs in the "Network Configuration Protocol (NETCONF) Capability URNs" registry:
Index Capability Identifier --------------------- :yang-library urn:ietf:params:netconf:capability:yang-library:1.1 :with-operational-defaults urn:ietf:params:netconf:capability:with-operational-defaults:1.0
This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in RFC 3688, the following registration has been made.
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-nmda Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the "YANG Module Names" registry [RFC6020].
name: ietf-netconf-nmda namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-nmda prefix: ncds reference: RFC XXXX
The YANG module defined in this document extends the base operations of the NETCONF [RFC6241] protocol. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242].
The network configuration access control model [RFC8341] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content.
The security considerations for the base NETCONF protocol operations (see Section 9 of [RFC6241]) apply to the new NETCONF <get‑data> and <edit‑data> operations defined in this document.
| [I-D.ietf-netconf-rfc7895bis] | Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K. and R. Wilton, "YANG Library", Internet-Draft draft-ietf-netconf-rfc7895bis-06, April 2018. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "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. |
| [RFC6243] | Bierman, A. and B. Lengyel, "With-defaults Capability for NETCONF", RFC 6243, DOI 10.17487/RFC6243, June 2011. |
| [RFC6991] | Schoenwaelder, J., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013. |
| [RFC7950] | Bjorklund, M., "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. |
| [RFC8341] | Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018. |
| [RFC8342] | Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018. |
| [RFC8340] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018. |