--- 1/draft-ietf-netmod-yang-json-04.txt 2015-09-10 02:15:13.925233292 -0700
+++ 2/draft-ietf-netmod-yang-json-05.txt 2015-09-10 02:15:13.961234161 -0700
@@ -1,203 +1,209 @@
NETMOD Working Group L. Lhotka
Internet-Draft CZ.NIC
-Intended status: Standards Track June 12, 2015
-Expires: December 14, 2015
+Intended status: Standards Track September 10, 2015
+Expires: March 13, 2016
JSON Encoding of Data Modeled with YANG
- draft-ietf-netmod-yang-json-04
+ draft-ietf-netmod-yang-json-05
Abstract
This document defines encoding rules for representing configuration,
- state data, RPC input and output parameters, and notifications
- defined using YANG as JavaScript Object Notation (JSON) text.
+ state data, RPC operation or action input and output parameters, and
+ notifications defined using YANG as JavaScript Object Notation (JSON)
+ text.
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 http://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 December 14, 2015.
+ This Internet-Draft will expire on March 13, 2016.
Copyright Notice
Copyright (c) 2015 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
(http://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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology and Notation . . . . . . . . . . . . . . . . . . 3
- 3. Validation of JSON-encoded
- Instance Data . . . . . . . . . . . . . . . . . . . . . . . . 4
+ 3. Properties of the JSON Encoding . . . . . . . . . . . . . . . 4
4. Names and Namespaces . . . . . . . . . . . . . . . . . . . . 4
5. Encoding of YANG Data Node Instances . . . . . . . . . . . . 6
5.1. The "leaf" Data Node . . . . . . . . . . . . . . . . . . 7
5.2. The "container" Data Node . . . . . . . . . . . . . . . . 7
5.3. The "leaf-list" Data Node . . . . . . . . . . . . . . . . 7
5.4. The "list" Data Node . . . . . . . . . . . . . . . . . . 8
5.5. The "anydata" Data Node . . . . . . . . . . . . . . . . . 9
5.6. The "anyxml" Data Node . . . . . . . . . . . . . . . . . 10
- 6. The Mapping of YANG Data Types to JSON Values . . . . . . . . 10
+ 6. Representing YANG Data Types in JSON Values . . . . . . . . . 10
6.1. Numeric Types . . . . . . . . . . . . . . . . . . . . . . 10
6.2. The "string" Type . . . . . . . . . . . . . . . . . . . . 11
6.3. The "boolean" Type . . . . . . . . . . . . . . . . . . . 11
6.4. The "enumeration" Type . . . . . . . . . . . . . . . . . 11
6.5. The "bits" Type . . . . . . . . . . . . . . . . . . . . . 11
6.6. The "binary" Type . . . . . . . . . . . . . . . . . . . . 11
- 6.7. The "leafref" Type . . . . . . . . . . . . . . . . . . . 11
- 6.8. The "identityref" Type . . . . . . . . . . . . . . . . . 11
+ 6.7. The "leafref" Type . . . . . . . . . . . . . . . . . . . 12
+ 6.8. The "identityref" Type . . . . . . . . . . . . . . . . . 12
6.9. The "empty" Type . . . . . . . . . . . . . . . . . . . . 12
6.10. The "union" Type . . . . . . . . . . . . . . . . . . . . 13
- 6.11. The "instance-identifier" Type . . . . . . . . . . . . . 13
+ 6.11. The "instance-identifier" Type . . . . . . . . . . . . . 14
7. I-JSON Compliance . . . . . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . 16
Appendix A. A Complete Example . . . . . . . . . . . . . . . . . 16
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 18
- B.1. Changes Between Revisions -03 and -04 . . . . . . . . . . 18
- B.2. Changes Between Revisions -02 and -03 . . . . . . . . . . 19
- B.3. Changes Between Revisions -01 and -02 . . . . . . . . . . 19
- B.4. Changes Between Revisions -00 and -01 . . . . . . . . . . 19
- Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 19
+ B.1. Changes Between Revisions -04 and -05 . . . . . . . . . . 18
+ B.2. Changes Between Revisions -03 and -04 . . . . . . . . . . 18
+ B.3. Changes Between Revisions -02 and -03 . . . . . . . . . . 19
+ B.4. Changes Between Revisions -01 and -02 . . . . . . . . . . 19
+ B.5. Changes Between Revisions -00 and -01 . . . . . . . . . . 19
+ Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
The NETCONF protocol [RFC6241] uses XML [W3C.REC-xml-20081126] for
encoding data in its Content Layer. Other management protocols might
want to use other encodings while still benefiting from using YANG
[I-D.ietf-netmod-rfc6020bis] as the data modeling language.
For example, the RESTCONF protocol [I-D.ietf-netconf-restconf]
supports two encodings: XML (media type "application/yang.data+xml")
and JSON (media type "application/yang.data+json).
The specification of YANG 1.1 data modelling language
[I-D.ietf-netmod-rfc6020bis] defines only XML encoding for data
instances, i.e., contents of configuration datastores, state data,
- RFC input and output parameters, and event notifications. The aim of
- this document is to define rules for encoding the same data as
- JavaScript Object Notation (JSON) text [RFC7159].
-
- In order to achieve maximum interoperability while allowing
- implementations to use a variety of available JSON parsers, the JSON
- encoding rules follow, as much as possible, the constraints of the
- I-JSON restricted profile [RFC7493]. Section 7 discusses I-JSON
- conformance in more detail.
+ RPC operation or action input and output parameters, and event
+ notifications. The aim of this document is to define rules for
+ encoding the same data as JavaScript Object Notation (JSON)
+ text [RFC7159].
2. Terminology and Notation
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].
The following terms are defined in [I-D.ietf-netmod-rfc6020bis]:
+ o action,
+
o anydata,
o anyxml,
o augment,
o container,
o data node,
+ o data tree,
+
o identity,
o instance identifier,
o leaf,
o leaf-list,
o list,
o module,
+ o RPC operation,
o submodule.
-3. Validation of JSON-encoded Instance Data
+3. Properties of the JSON Encoding
- Instance data validation as defined in [I-D.ietf-netmod-rfc6020bis],
- sec. 8.3.3, is only applicable to XML-encoded data. For one,
- semantic constraints in "must" statements are expressed using
- XPath 1.0 [W3C.REC-xpath-19991116], which can be properly interpreted
- only in the XML context.
+ This document defines JSON encoding for YANG data trees and their
+ subtrees. It is always assumed that the top-level structure in JSON-
+ encoded data is an object.
- This document and the corresponding "XML Mapping Rules" sections from
- [I-D.ietf-netmod-rfc6020bis] also define an implicit schema-driven
- mapping of JSON-encoded instances to XML-encoded instances (and vice
- versa). This mapping is mostly straightforward. In cases where
- doubts could arise, this document gives explicit instructions for
- mapping JSON-encoded instances to XML.
+ Instances of YANG data nodes (leafs, containers, leaf-lists, lists,
+ anydata and anyxml nodes) are encoded as members of a JSON object,
+ i.e., name/value pairs. Section 4 defines how the name part is
+ formed, and the following sections deal with the value part.
- In order to validate a JSON instance document, it needs first to be
- mapped, at least conceptually, to the corresponding XML instance
- document. By definition, the JSON document is then valid if and only
- if the XML document is valid according to the rules stated in
- [I-D.ietf-netmod-rfc6020bis].
+ Unlike XML element content, JSON values carry partial type
+ information (number, string, boolean). The JSON encoding is defined
+ so that this information is never in conflict with the data type of
+ the corresponding YANG leaf or leaf-list.
+
+ With the exception of anyxml and schema-less anydata nodes, it is
+ possible to map a JSON-encoded data tree to XML encoding as defined
+ in [I-D.ietf-netmod-rfc6020bis], and vice versa. However, such
+ conversions require the YANG data model to be available.
+
+ In order to achieve maximum interoperability while allowing
+ implementations to use a variety of existing JSON parsers, the JSON
+ encoding rules follow, as much as possible, the constraints of the
+ I-JSON restricted profile [RFC7493]. Section 7 discusses I-JSON
+ conformance in more detail.
4. Names and Namespaces
- Instances of YANG data nodes (leafs, containers, leaf-lists, lists,
- anydata and anyxml nodes) are always encoded as members of a JSON
- object, i.e., as name/value pairs. This section defines how the name
- part is formed, and the following sections deal with the value part.
+ An object member name MUST be in one of the following forms:
- Except in the cases specified below, the member name is identical to
- the identifier of the corresponding YANG data node. Every such name
- belongs to a namespace which is associated with the YANG module where
- the corresponding data node is defined. If the data node is defined
- in a submodule, then the namespace is determined by the main module
- to which the submodule belongs.
+ o simple - identical to the identifier of the corresponding YANG
+ data node;
- If the namespace of a member name has to be explicitly specified, the
- module name SHALL be used as a prefix to the member's local name.
- Both parts of the member name SHALL be separated with a colon
- character (":"). Using ABNF [RFC5234], the namespace-qualified name
- can be expressed as shown in Figure 1, where the production for
- "identifier" is defined in sec. 13 of [I-D.ietf-netmod-rfc6020bis].
+ o namespace-qualified - the data node identifier is prefixed with
+ the name of the module in which the data node is defined, and
+ separated by the colon character (":").
- qualified-member-name = identifier ":" identifier
+ The name of a module determines the namespace of all data node names
+ defined in that module. If a data node is defined in a submodule,
+ then the namespace-qualified member name uses the name of the main
+ module to which the submodule belongs.
- Figure 1: ABNF production for a qualified member name.
+ ABNF syntax [RFC5234] of a member name is shown in Figure 1, where
+ the production for "identifier" is defined in sec. 13 of
+ [I-D.ietf-netmod-rfc6020bis].
- Names with namespace identifiers in the form shown in Figure 1 are
- used if and only if the parent data node belongs to a different
- namespace, which also includes all top-level YANG data nodes that
- have no parent node.
+ member-name = [identifier ":"] identifier
+
+ Figure 1: ABNF production for a JSON member name.
+
+ A namespace-qualified member name MUST be used for all members of a
+ top-level JSON object, and then also whenever the namespaces of the
+ data node and its parent node are different. In all other cases, the
+ simple form of the member name MUST be used.
For example, consider the following YANG module:
module foomod {
namespace "http://example.com/foomod";
prefix "foo";
container top {
@@ -209,23 +215,23 @@
If the data model consists only of this module, then the following is
a valid JSON-encoded configuration:
{
"foomod:top": {
"foo": 54
}
}
- Note that the top-level container instance contains the namespace
- identifier (module name) but the "foo" leaf doesn't because it is
- defined in the same module as its parent container.
+ Note that the member of the top-level object uses the namespace-
+ qualified name but the "foo" leaf doesn't because it is defined in
+ the same module as its parent container "top".
Now, assume the container "top" is augmented from another module,
"barmod":
module barmod {
namespace "http://example.com/barmod";
prefix "bar";
@@ -244,41 +250,36 @@
look like this:
{
"foomod:top": {
"foo": 54,
"barmod:bar": true
}
}
The name of the "bar" leaf is prefixed with the namespace identifier
- because its parent is defined in a different module, hence it belongs
- to another namespace.
+ because its parent is defined in a different module.
Explicit namespace identifiers are sometimes needed when encoding
values of the "identityref" and "instances-identifier" types. The
- same form as shown in Figure 1 is then used as well. See Sections
- 6.8 and 6.11 for details.
+ same form of namespace-qualified name as defined above is then used.
+ See Sections 6.8 and 6.11 for details.
5. Encoding of YANG Data Node Instances
- Every complete JSON instance document, such as a configuration
- datastore content, is an object. Its members are instances of all
- top-level data nodes defined by the YANG data model.
+ Every data node instance is encoded as a name/value pair where the
+ name is formed from the data node identifier using the rules of
+ Section 4. The value depends on the category of the data node as
+ explained in the following subsections.
Character encoding MUST be UTF-8.
- Any data node instance is encoded as a name/value pair where the name
- is formed from the data node identifier using the rules of Section 4.
- The value depends on the category of the data node as explained in
- the following subsections.
-
5.1. The "leaf" Data Node
A leaf instance is encoded as a name/value pair where the value can
be a string, number, literal "true" or "false", or the special array
"[null]", depending on the type of the leaf (see Section 6 for the
type encoding rules).
Example: For the leaf node definition
leaf foo {
@@ -368,48 +369,42 @@
},
{
"baz": "zag",
"foo": 0
}
]
5.5. The "anydata" Data Node
Anydata data node is a new feature in YANG 1.1. It serves as a
- container for data that appear as normal YANG-modeled data, except
- their data model is not a priori known.
+ container for an unknown set of nodes that however appear as normal
+ YANG-modeled data. A data model for anydata content may or may not
+ exist at run time. In the latter case, no universal mapping between
+ JSON- and XML-encoded instances is available.
- An anydata instance is thus encoded in the same way as a container,
- and its content is subject to the following rules:
+ An anydata instance is encoded in the same way as a container, i.e.,
+ as a value/object pair. The requirement that anydata content can be
+ modeled by YANG implies the following rules for JSON text inside the
+ object:
- o It is a valid I-JSON message [RFC7493].
+ o It is valid I-JSON [RFC7493].
- o Any member name is either a YANG identifier as defined by the
- "identifier" production in sec. 13 of
- [I-D.ietf-netmod-rfc6020bis], or two such identifiers separated by
- the colon character (":"). See also Section 4.
+ o All object member names satisfy the ABNF production in Figure 1.
o Any JSON array contains either only unique scalar values (as a
leaf-list, see Section 5.3), or only objects (as a list, see
Section 5.4).
o The "null" value is only allowed in the single-element array
"[null]" corresponding to the encoding of the "empty" type, see
Section 6.9.
- If a data model for anydata content is not available, it may be
- impossible to map a JSON-encoded anydata instance to XML, and vice
- versa. Note, however, that such a mapping is not needed for
- validation purposes (Section 3) because anydata contents are
- generally not subject to YANG-based validation (see sec. 7.10 in
- [I-D.ietf-netmod-rfc6020bis]).
-
Example: for the anydata definition
anydata data;
the following is a valid JSON-encoded instance:
"data": {
"ietf-notification:notification": {
"eventTime": "2014-07-29T13:43:01Z",
"example-event:event": {
@@ -422,97 +417,104 @@
}
}
5.6. The "anyxml" Data Node
An anyxml instance is encoded as a JSON name/value pair which MUST
satisfy I-JSON constraints. Otherwise it is unrestricted, i.e., the
value can be an object, array, number, string or one of the literals
"true", "false" and "null".
- As in the case of anydata (Section 5.5), there is no universal
- procedure for mapping JSON-encoded anyxml instances to XML, and vice
- versa.
+ There is no universal procedure for mapping JSON-encoded anyxml
+ instances to XML, and vice versa.
Example: For the anyxml definition
anyxml bar;
the following is a valid JSON-encoded instance:
"bar": [true, null, true]
-6. The Mapping of YANG Data Types to JSON Values
+6. Representing YANG Data Types in JSON Values
The type of the JSON value in an instance of the leaf or leaf-list
data node depends on the type of that data node as specified in the
following subsections.
6.1. Numeric Types
- A value of the "int8", "int16", "int32", "uint8", "uint16" and
+ A value of the types "int8", "int16", "int32", "uint8", "uint16" and
"uint32" is represented as a JSON number.
- A value of the "int64", "uint64" or "decimal64" type is encoded as a
- JSON string whose contents is the lexical representation of that
- numeric value as specified in sections 9.2.1 and 9.3.1 of
+ A value of the "int64", "uint64" or "decimal64" type is represented
+ as a JSON string whose content is the lexical representation of the
+ corresponding YANG type as specified in sections 9.2.1 and 9.3.1 of
[I-D.ietf-netmod-rfc6020bis].
For example, if the type of the leaf "foo" in Section 5.1 was
"uint64" instead of "uint8", the instance would have to be encoded as
"foo": "123"
- The special handling of 64-bit numbers follows from I-JSON
+ The special handling of 64-bit numbers follows from the I-JSON
recommendation to encode numbers exceeding the IEEE 754-2008 double
precision range as strings, see sec. 2.2 in [RFC7493].
6.2. The "string" Type
- A "string" value encoded as a JSON string, subject to JSON string
+ A "string" value represented as a JSON string, subject to JSON string
encoding rules.
6.3. The "boolean" Type
- A "boolean" value is mapped to the corresponding JSON literal name
- "true" or "false".
+ A "boolean" value is represented as the corresponding JSON literal
+ name "true" or "false".
6.4. The "enumeration" Type
- An "enumeration" value is mapped in the same way as a string except
- that the permitted values are defined by "enum" statements in YANG.
- See sec. 9.6 in [I-D.ietf-netmod-rfc6020bis].
+ An "enumeration" value is represented as a JSON string - one of the
+ names assigned by "enum" statements in YANG.
+
+ The representation is identical to the lexical representation of the
+ "enumeration" type in XML, see sec. 9.6 in
+ [I-D.ietf-netmod-rfc6020bis].
6.5. The "bits" Type
- A "bits" value is mapped to a JSON string identical to the lexical
- representation of this value in XML, i.e., space-separated names
- representing the individual bit values that are set. See sec. 9.7 in
- [I-D.ietf-netmod-rfc6020bis].
+ A "bits" value is represented as a JSON string - a space-separated
+ sequence of names of bits that are set. The permitted bit names are
+ assigned by "bit" statements in YANG.
+
+ The representation is identical to the lexical representation of the
+ "bits" type, see sec. 9.7 in [I-D.ietf-netmod-rfc6020bis].
6.6. The "binary" Type
- A "binary" value is mapped to a JSON string identical to the lexical
- representation of this value in XML, i.e., base64-encoded binary
- data. See sec. 9.8 in [I-D.ietf-netmod-rfc6020bis].
+ A "binary" value is represented as a JSON string - base64-encoding of
+ arbitrary binary data.
+
+ The representation is identical to the lexical representation of the
+ "binary" type in XML, see sec. 9.8 in [I-D.ietf-netmod-rfc6020bis].
6.7. The "leafref" Type
- A "leafref" value is mapped according to the same rules as the type
- of the leaf being referred to.
+ A "leafref" value is represented using the same rules as the type of
+ the leaf to which the leafref value refers.
6.8. The "identityref" Type
- An "identityref" value is mapped to a string representing the name of
- an identity. Its namespace MUST be expressed as shown in Figure 1 if
- it is different from the namespace of the leaf node containing the
- identityref value, and MAY be expressed otherwise.
+ An "identityref" value is represented as a string - the name of an
+ identity. If the identity is defined in another module than the leaf
+ node containing the identityref value, the namespace-qualified form
+ (Section 4) MUST be used. Otherwise, both the simple and namespace-
+ qualified forms are permitted.
For example, consider the following schematic module:
module exmod {
...
import ietf-interfaces {
prefix if;
}
import iana-if-type {
prefix ianaift;
@@ -528,132 +530,119 @@
A valid instance of the "type" leaf is then encoded as follows:
"type": "iana-if-type:ethernetCsmacd"
The namespace identifier "iana-if-type" must be present in this case
because the "ethernetCsmacd" identity is not defined in the same
module as the "type" leaf.
6.9. The "empty" Type
- An "empty" value is mapped to "[null]", i.e., an array with the
+ An "empty" value is represented as "[null]", i.e., an array with the
"null" literal being its only element. For the purposes of this
- document, "[null]" is treated as an atomic scalar value.
+ document, "[null]" is considered an atomic scalar value.
This encoding of the "empty" type was chosen instead of using simply
"null" in order to facilitate the use of empty leafs in common
- programming languages. When used in a boolean context, the "[null]"
- value, unlike "null", evaluates to true.
+ programming languages where the "null" value of a member is treated
+ as if the member is not present.
Example: For the leaf definition
leaf foo {
type empty;
}
a valid instance is
+
"foo": [null]
6.10. The "union" Type
A value of the "union" type is encoded as the value of any of the
member types.
- Unlike XML, JSON conveys part of the type information already in the
- encoding. When validating a value of the "union" type, this
- information MUST also be taken into account.
+ When validating a value of the "union" type, the type information
+ conveyed by the JSON encoding MUST also be taken into account.
For example, consider the following YANG definition:
leaf bar {
type union {
type uint16;
type string;
}
}
- In RESTCONF [I-D.ietf-netconf-restconf], it is fully acceptable to
- set the value of "bar" in the following way when using the
- "application/yang.data+xml" media type:
+ In RESTCONF [I-D.ietf-netconf-restconf], it is possible to set the
+ value of "bar" in the following way when using the "application/
+ yang.data+xml" media type:
13.5
because the value may be interpreted as a string, i.e., the second
member type of the union. When using the "application/
yang.data+json" media type, however, this is an error:
"bar": 13.5
In this case, the JSON encoding indicates the value is supposed to be
a number rather than a string.
6.11. The "instance-identifier" Type
An "instance-identifier" value is encoded as a string that is
analogical to the lexical representation in XML encoding, see
sec. 9.13.3 in [I-D.ietf-netmod-rfc6020bis]. However, the encoding
of namespaces in instance-identifier values follows the rules stated
in Section 4, namely:
- o The namespace identifier is the module name where each data node
- is defined.
-
- o The encoding of a node name with an explicit namespace is as shown
- in Figure 1.
-
- o The leftmost (top-level) node name is always prefixed with the
- namespace identifier.
+ o The leftmost (top-level) data node name is always in the
+ namespace-qualified form.
- o Any subsequent node name has the namespace identifier if and only
- if its parent node has a different namespace. This also holds for
- node names appearing in predicates.
+ o Any subsequent data node name is in the namespace-qualified form
+ if the node is defined in another module than its parent node, and
+ the simple form is used otherwise. This rule also holds for node
+ names appearing in predicates.
For example,
/ietf-interfaces:interfaces/interface[name='eth0']/ietf-ip:ipv4/ip
is a valid instance-identifer value because the data nodes
"interfaces", "interface" and "name" are defined in the module "ietf-
interfaces", whereas "ipv4" and "ip" are defined in "ietf-ip".
- When translating an instance-identifier value from JSON to XML, the
- namespace identifier (YANG module name) in each component of the
- instance-identifier MUST be replaced by an XML namespace prefix that
- is associated with the namespace URI reference of the module in the
- scope of the element containing the instance-identifier value.
-
7. I-JSON Compliance
I-JSON [RFC7493] is a restricted profile of JSON that guarantees
maximum interoperability for protocols that use JSON in their
messages, no matter what JSON encoders/decoders are used in protocol
implementations. The encoding defined in this document therefore
observes the I-JSON requirements and recommendations as closely as
possible.
In particular, the following properties are guaranteed:
o Character encoding is UTF-8.
o Member names within the same JSON object are always unique.
o The order of JSON object members is never relied upon.
o Numbers of any type supported by YANG can be exchanged reliably.
See Section 6.1 for details.
- This document deviates from I-JSON only in the encoding of values
- with the "binary" type. It uses the base64 encoding scheme
+ The JSON encoding defined in this document deviates from I-JSON only
+ in the representation of the "binary" type. In order to remain
+ compatible with XML encoding, the base64 encoding scheme is used
(Section 6.6), whereas I-JSON recommends base64url instead.
- Theoretically, values of the "binary" type might appear in URI
- references, such as Request-URI in RESTCONF, although in practice the
- cases where it is really needed should be extremely rare.
8. Security Considerations
This document defines an alternative encoding for data modeled in the
YANG data modeling language. As such, it doesn't contribute any new
security issues beyond those discussed in sec. 16 of
[I-D.ietf-netmod-rfc6020bis].
JSON processing is rather different from XML, and JSON parsers may
thus suffer from other types of vulnerabilities than their XML
@@ -668,60 +657,62 @@
Bogdanovic, Balazs Lengyel, Juergen Schoenwaelder and Phil Shafer for
their helpful comments and suggestions.
10. References
10.1. Normative References
[I-D.ietf-netmod-rfc6020bis]
Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", draft-ietf-
- netmod-rfc6020bis-05 (work in progress), May 2015.
+ netmod-rfc6020bis-06 (work in progress), July 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
- Requirement Levels", BCP 14, RFC 2119, March 1997.
-
- [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
- Specifications: ABNF", STD 68, RFC 5234, January 2008.
+ Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
+ RFC2119, March 1997,
+ .
- [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
- Bierman, "Network Configuration Protocol (NETCONF)", RFC
- 6241, June 2011.
+ [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
+ Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/
+ RFC5234, January 2008,
+ .
- [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data
- Interchange Format", RFC 7159, March 2014.
+ [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,
+ .
- [RFC7493] Bray, T., "The I-JSON Message Format", RFC 7493, March
- 2015.
+ [RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
+ Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
+ 2014, .
- [W3C.REC-xml-20081126]
- Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
- F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
- Edition)", World Wide Web Consortium Recommendation REC-
- xml-20081126, November 2008,
- .
+ [RFC7493] Bray, T., Ed., "The I-JSON Message Format", RFC 7493, DOI
+ 10.17487/RFC7493, March 2015,
+ .
10.2. Informative References
[I-D.ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
- Protocol", draft-ietf-netconf-restconf-05 (work in
- progress), June 2015.
+ Protocol", draft-ietf-netconf-restconf-07 (work in
+ progress), July 2015.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
- Management", RFC 7223, May 2014.
+ Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
+ .
- [W3C.REC-xpath-19991116]
- Clark, J. and S. DeRose, "XML Path Language (XPath)
- Version 1.0", World Wide Web Consortium Recommendation
- REC-xpath-19991116, November 1999,
- .
+ [W3C.REC-xml-20081126]
+ Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
+ F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
+ Edition)", World Wide Web Consortium Recommendation REC-
+ xml-20081126, November 2008,
+ .
Appendix A. A Complete Example
The JSON document shown below represents the same data as the reply
to the NETCONF request appearing in Appendix D of [RFC7223].
The data model is a combination of two YANG modules: "ietf-
interfaces" and "ex-vlan" (the latter is an example module from
Appendix C of [RFC7223]). The "if-mib" feature defined in the "ietf-
interfaces" module is considered to be active.
@@ -815,50 +806,57 @@
}
}
]
}
}
Appendix B. Change Log
RFC Editor: Remove this section upon publication as an RFC.
-B.1. Changes Between Revisions -03 and -04
+B.1. Changes Between Revisions -04 and -05
+
+ o Removed section "Validation of JSON-encoded Instance Data" and
+ other text about XML-JSON mapping.
+
+ o Added section "Properties of the JSON Encoding".
+
+B.2. Changes Between Revisions -03 and -04
o I-D.ietf-netmod-rfc6020bis is used as a normative reference
instead of RFC 6020.
o Removed noncharacters as an I-JSON issue because it doesn't exist
in YANG 1.1.
o Section about anydata encoding was added.
o Require I-JSON for anyxml encoding.
o Use ABNF for defining qualified name.
-B.2. Changes Between Revisions -02 and -03
+B.3. Changes Between Revisions -02 and -03
o Namespace encoding is defined without using RFC 2119 keywords.
o Specification for anyxml nodes was extended and clarified.
o Text about ordering of list entries was corrected.
-B.3. Changes Between Revisions -01 and -02
+B.4. Changes Between Revisions -01 and -02
o Encoding of namespaces in instance-identifiers was changed.
o Text specifying the order of array elements in leaf-list and list
instances was added.
-B.4. Changes Between Revisions -00 and -01
+B.5. Changes Between Revisions -00 and -01
o Metadata encoding was moved to a separate I-D, draft-lhotka-
netmod-yang-metadata.
o JSON encoding is now defined directly rather than via XML-JSON
mapping.
o The rules for namespace encoding has changed. This affect both
node instance names and instance-identifiers.