Internet DRAFT - draft-mahesh-netconf-accounting
draft-mahesh-netconf-accounting
Network Working Group M. Jethanandani
Internet-Draft Cisco Systems, Inc
Intended status: Standards Track July 17, 2017
Expires: January 18, 2018
Accounting in NETCONF and RESTCONF
draft-mahesh-netconf-accounting-03
Abstract
This document defines an accounting record for NETCONF and RESTCONF.
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 RFC 2119 [RFC2119].
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 January 18, 2018.
Copyright Notice
Copyright (c) 2017 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Compatability with remote AAA servers . . . . . . . . . . 2
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Accounting Record . . . . . . . . . . . . . . . . . . . . . . 3
3. Data Model Definitions . . . . . . . . . . . . . . . . . . . 5
3.1. Data Organization . . . . . . . . . . . . . . . . . . . . 5
3.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1. Normative References . . . . . . . . . . . . . . . . . . 11
7.2. Informative References . . . . . . . . . . . . . . . . . 12
Appendix A. Accounting model examples . . . . . . . . . . . . . 12
A.1. <edit-config> Example for Accounting . . . . . . . . . . 12
A.2. <get> Example for Accounting . . . . . . . . . . . . . . 12
A.3. NACM rule for Accounting . . . . . . . . . . . . . . . . 13
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
NETCONF [RFC6241] and RESTCONF [RFC8040] protocol operations are
authenticated and authorized as part of the Authentication,
Authorization and Accounting (AAA) framework. An accounting record
is generated as part of the same framework for each of these
operations to satisfy the accounting part of AAA, but there has been
no effort to define such a record. Having an accounting record that
is consistent across vendors allows for the operator to compare
operations across devices from different vendors. This document
defines such a record and a corresponding YANG data model (ietf-
netconf-am.yang).
The rest of this document will use NETCONF to imply both NETCONF and
RESTCONF, but where applicable will call out each protocol
specifically.
1.1. Compatability with remote AAA servers
This document does not cover how the server interacts with remote AAA
servers and any interaction is out of scope of this document. A
particular implementation can make the records available as part of
<get> request, send a notification every time a accounting record is
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generated or use any existing protocol to update the remote AAA
server.
1.2. Terminology
The following terms are defined in NETCONF [RFC6241] and are not
redefined here:
o client
o <get>
o notification
o server
o session
o user
And the following terms are defined in NACM [RFC6536] and are not
redefined here.
o data-node
o action
o rule
2. Accounting Record
An accounting record for NETCONF consists of the following fields.
Note, there is no accounting record for reading or notification of an
accounting record.
+------+------+----+-----+-----+-----+-----+------+-----+-----+-----+
| mess | sess | sr | dat | use | gro | rul | data | val | act | sta |
| age- | ion- | c- | e-t | r | ups | e | - | ue | ion | tus |
| id | id | ip | ime | | | | node | | | |
+------+------+----+-----+-----+-----+-----+------+-----+-----+-----+
+------+------+----+-----+-----+-----+-----+------+-----+-----+-----+
where:
message-id: This is the id within a given NETCONF session assigned to
each RPC. RESTCONF has no concept of a session, so this field would
be left blank.
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session-id: The session-id in case of NETCONF and would be blank in
case of RESTCONF. If the accounting record needs to be fragmented
for any reason, it is suggested that this field not be repeated in
subsequent packets. Instead a combination of start and end record
marker, and the message-id should be used to reassemble fragmented
records.
src-ip: The source IP address that was used to request the operation.
If the accounting record needs to be fragmented for any reason, it is
suggested that this field not be repeated in subsequent packets.
Instead a combination of start and end record marker, and the
message-id should be used to reassemble fragmented records.
date-time: The date and time when the operation was performed (UTC
Timezone). If the accounting record needs to be fragmented for any
reason, it is suggested that this field not be repeated in subsequent
packets. Instead a combination of start and end record marker, and
the message-id should be used to reassemble fragmented records.
user: The NETCONF user that requesed this operation. If the
accounting record needs to be fragmented for any reason, it is
suggested that this field not be repeated in subsequent packets.
Instead a combination of start and end record marker, and the
message-id should be used to reassemble fragmented records.
groups: The group the user belongs to. If the accounting record
needs to be fragmented for any reason, it is suggested that this
field not be repeated in subsequent packets. Instead a combination
of start and end record marker, and the message-id should be used to
reassemble fragmented records.
data-node: The data-node in the NACM [RFC6536] rule on which the
operations is being performed
value: The value that was set for any of the attributes in the
request
action: The action in the NACM [RFC6536] rule
rule: The rule in the NACM [RFC6536] that was matched to authorize
the action.
status: Whether the operations was permitted or denied.
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3. Data Model Definitions
The model uses the NACM extension statement of default-deny-all to
protect accounting records. Explicit rules have to be defined to be
enable access to the accounting records.
3.1. Data Organization
The following diagram highlights the contents and structure of the
Accounting YANG module. For information on annotations, please refer
to YANG Tree Diagrams [I-D.ietf-netmod-yang-tree-diagrams].
module: ietf-netconf-am
+--rw nam
+--rw enable-nam? boolean
+--ro accounting-record* [session-id message-id]
+--ro session-id nc:session-id-type
+--ro message-id uint32
+--ro date-time yang:date-and-time
+--ro src-ip inet:ip-address
+--ro group nacm:group-name-type
+--ro user? nacm:user-name-type
+--ro rule? string
+--ro data-node nacm:node-instance-identifier
+--ro value?
+--ro action nacm:access-operations-type
+--ro status? nacm:action-type
3.2. YANG Module
The following YANG module specifies the normative NETCONF content
that MUST be supported by the server.
The "ietf-netconf-am" YANG module imports typedefs from YANG-TYPES
[RFC6991], from NETCONF [RFC6241] and from NACM [RFC6536].
<CODE BEGINS> file "ietf-netconf-am@2017-07-16.yang"
module ietf-netconf-am {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-am";
prefix "nam";
import ietf-inet-types {
prefix inet;
}
import ietf-yang-types {
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prefix yang;
}
import ietf-netconf {
prefix nc;
}
import ietf-netconf-acm {
prefix nacm;
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
WG Chair: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>
Editor: Mahesh Jethanandani
<mailto:mjethanandani@gmail.com>";
description
"This module defines an accounting record for NETCONF operations
performed on the server. If these operations are authorized
using rules defined by NACM [RFC6536], then that information is
also captured by this module.
Copyright (c) 2014 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; see
the RFC itself for full legal notices.";
revision "2017-07-16" {
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description
"Initial version";
reference
"RFC XXXX: NETCONF and RESTCONF Accounting";
}
/*
* Data definition statements.
*/
container nam {
nacm:default-deny-all;
description
"Parameters for NETCONF Accounting Model.";
leaf enable-nam {
type boolean;
default true;
description
"Enable or disable generation of NETCONF
accounting records. If 'true', accounting
records will be generated. If set to 'false'
no accounting records will be generated.";
}
list accounting-record {
key "session-id message-id";
config false;
description
"A list of accounting records generated by the server";
leaf session-id {
type nc:session-id-type;
description
"If this operation happened over NETCONF, this
field captures the NETCONF session-id. In case
of RESTCONF this field can be left blank.";
}
leaf message-id {
type uint32;
description
"Id that is assigned to each RPC within a given
NETCONF session. Should be blank in case of
RESTCONF.";
}
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leaf date-time {
type yang:date-and-time;
mandatory true;
description
"The date and time when the operation was
requested.";
}
leaf src-ip {
type inet:ip-address;
mandatory true;
description
"The source IP address where the request was made
from.";
}
leaf group {
type nacm:group-name-type;
mandatory true;
description
"The name of the group that the user who requested
the operation belongs to.";
}
leaf user {
type nacm:user-name-type;
description
"The user within the group that is requesting this
operation.";
}
leaf rule {
type string {
length "1..max";
}
description
"The name assigned to the rule that was used to
authorize the action, if authorization was
enabled.";
}
leaf data-node {
type nacm:node-instance-identifier;
mandatory true;
description
"Data Node Instance Identifier associated with the
data node that the request is being made on.
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Instance identifiers start with the top-level
data node, and a complete identifier is required
for this value.";
}
anydata value {
description
"An optional field, it contains the value of any
of the attribute that form the record.
It could be as simple as the filter value
'http' specified that the user requested as part
of the authorization request such as in this
example:
<filter>
<name>http</name>
</filter>
or it could be value being set for a ssh port
in this example:
<ssh>
<port>2022</port>
</ssh>";
}
leaf action {
type nacm:access-operations-type;
mandatory true;
description
"The type of NETCONF operation being requested.";
}
leaf status {
type nacm:action-type;
description
"Action taken by the server when the above
mentioned rule matched, if authorization was
enable.";
}
}
}
}
<CODE ENDS>
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4. IANA Considerations
This document makes two requests of IANA.
The first request is to register one URI in "The IETF XML Registry".
Following the format in The IETF XML Registry [RFC3688], the
following needs to be registered.
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-am
Registrant Contact: The IESG
XML: N/A, the requested URI is an XML namespace
The second request is to register one module in the "YANG Module
Names" registry. Following the format in YANG [RFC7950], the
following needs to be registered.
Name: ietf-netconf-am
Namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-am
Prefix: nam
Reference: RFC XXXX
Note to RFC Editor - Please replace XXXX here and in the rest of the
draft with the RFC id assigned to this draft.
5. Security Considerations
The YANG module defined in this document is designed to be accessed
via network management protocol such as NETCONF [RFC6241] or RESTCONF
[RFC8040]. The lowest NETCONF layer is the secure transport layer,
and the mandatory-to-implement secure transport is Secure Shell (SSH)
[RFC6242]. The lowest RESTCONF layers is HTTPS, and the mandatory-
to-implement secure transport is TLS [RFC5246].
The NETCONF Access Control Model (NACM) [RFC6536] provides the means
to restrict access for particular NETCONF or RESTCONF users to a pre-
configured subset of all available NETCONF or RESTCONF protocol
operations and content.
Most of the data nodes defined in this YANG module are readonly, i.e.
config false, and are therefore not vulnerable to manipulation in
network environments. However, they might contain data that might be
sensitive and should be protected with the right NACM [RFC6536]
rules.
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6. Acknowledgements
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>.
[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,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<http://www.rfc-editor.org/info/rfc6242>.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<http://www.rfc-editor.org/info/rfc6536>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<http://www.rfc-editor.org/info/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<http://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<http://www.rfc-editor.org/info/rfc8040>.
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7.2. Informative References
[I-D.ietf-netmod-yang-tree-diagrams]
Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
ietf-netmod-yang-tree-diagrams-01 (work in progress), June
2017.
Appendix A. Accounting model examples
A.1. <edit-config> Example for Accounting
This example demonstrates how the configuration could be updated to
enable accounting. The attribute in the model that enables
accounting is enable-nam.
<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
message-id="4">
<edit-config xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<candidate/>
</target>
<test-option>test-then-set</test-option>
<error-option>rollback-on-error</error-option>
<config>
<nam xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-am">
<enable-nam>true</enable-nam>
</nam>
</config>
</edit-config>
</rpc>
A.2. <get> Example for Accounting
This example demonsrates what a <get> request and response might look
like.
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<rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
message-id="1">
<get>
<filter>
<nam xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-am">
<accounting-record/>
</nam>
</filter>
</get>
</rpc>
<rpc-reply message-id="1"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<nam xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-am">
<accounting-record>
<session-id>101</session-id>
<message-id>100</message-id>
<date-time>2017-06-19T16:39:57-08:00</date-time>
<src-ip>172.20.39.46</src-ip>
<group>netconf-group</group>
<user>netconf</user>
<path xmlns:acme="http://example.com/ns/itf">
/acme:interfaces/acme:interface
</path>
<value>
<name>GigabitEthernet0/0/0/0</name>
<admin-state>UP</admin-state>
</value>
<action>read</action>
<rule>51</rule>
<status>permit</status>
</accounting-record>
</nam>
</data>
</rpc-reply>
A.3. NACM rule for Accounting
This example demonstrates how NACM could be configured to permit
access to accounting records. Note, the model has default-deny-all
set to prevent access to accounting records by default, and expects
explicit rules to be configured to permit access.
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<nacm xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-acm">
<rule-list>
<name>root</name>
<group>root</group>
<rule>
<name>allow-nam</name>
<path xmlns:n="urn:ietf:params:xml:ns:yang:ietf-netconf-am">
/n:nam
</path>
<access-operations>read</access-operations>
<action>permit</action>
<comment>
Allow the root group read access to the /nam data.
</comment>
</rule>
</rule-list>
</nacm>
Author's Address
Mahesh Jethanandani
Cisco Systems, Inc
170 West Tasman Drive
San Jose, CA 95070
USA
Email: mjethanandani@gmail.com
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