NETCONF Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Standards Track March 9, 2019
Expires: September 10, 2019
YANG Groupings for TCP Clients and TCP Servers
draft-kwatsen-netconf-tcp-client-server-00
Abstract
This document defines two YANG modules: the first defines a grouping
for configuring a generic TCP client, and the second defines a
grouping for configuring a generic TCP server. It is intended that
these groupings will be used by applications using the TCP protocol.
Editorial Note (To be removed by RFC Editor)
This draft contains many placeholder values that need to be replaced
with finalized values at the time of publication. This note
summarizes all of the substitutions that are needed. No other RFC
Editor instructions are specified elsewhere in this document.
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
o "2019-03-09" --> the publication date of this draft
The following Appendix section is to be removed prior to publication:
o Appendix A. Change Log
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
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 10, 2019.
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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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The TCP Client Model . . . . . . . . . . . . . . . . . . . . 3
3.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 3
3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 4
4. The TCP Server Model . . . . . . . . . . . . . . . . . . . . 7
4.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 8
4.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 12
6.2. The YANG Module Names Registry . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
This document defines two YANG 1.1 [RFC7950] modules: the first
defines a grouping for configuring a generic TCP client, and the
second defines a grouping for configuring a generic TCP server. It
is intended that these groupings will be used by applications using
the TCP protocol. For instance, these groupings could help define
the configuration module for an SSH, TLS, or HTTP based application.
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2. Terminology
The key words "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.
3. The TCP Client Model
3.1. Tree Diagram
This section provides a tree diagram [RFC8340] for the "ietf-tcp-
client" module.
module: ietf-tcp-client
grouping tcp-client-grouping
+-- remote-address inet:host
+-- remote-port? inet:port-number
+-- local-address? inet:ip-address
+-- local-port? inet:port-number
+-- tcp-keepalives {tcp-client-keepalives}?
+-- idle-time? uint16
+-- max-probes? uint16
+-- probe-interval? uint16
grouping ip-params-grouping
+-- remote-address inet:host
+-- remote-port? inet:port-number
+-- local-address? inet:ip-address
+-- local-port? inet:port-number
grouping keepalives-grouping
+-- tcp-keepalives {tcp-client-keepalives}?
+-- idle-time? uint16
+-- max-probes? uint16
+-- probe-interval? uint16
3.2. Example Usage
This section presents an example showing the tcp-client-grouping
populated with some data.
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www.example.com
443
0.0.0.0
0
15
3
30
3.3. YANG Module
This YANG module has normative references to [RFC6991].
file "ietf-tcp-client@2019-03-09.yang"
module ietf-tcp-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-tcp-client";
prefix tcpc;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen ";
description
"This module defines reusable groupings for TCP clients that
can be used as a basis for specific TCP client instances.
The key words '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.
Copyright (c) 2019 IETF Trust and the persons identified as
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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 2019-03-09 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for TCP Clients and TCP Servers";
}
// Features
feature tcp-client-keepalives {
description
"Per socket TCP keepalive parameters are configurable for
TCP clients on the server implementing this feature.";
}
// Groupings
grouping tcp-client-grouping {
description
"A reusable grouping for configuring a TCP client.";
uses ip-params-grouping;
uses keepalives-grouping;
}
grouping ip-params-grouping {
description
"A reusable grouping for configuring TCP client IP level
parameters.";
leaf remote-address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the remote peer to connect to.
If a domain name is configured, then the DNS resolution
should happen on each connection attempt. If the the DNS
resolution results in multiple IP addresses, the IP addresses
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are tried according to local preference order until a
connection has been established or until all IP addresses
have failed.";
}
leaf remote-port {
type inet:port-number;
default "0";
description
"The IP port number for the remote peer to connect to. An
invalid default value (0) is used (instead of 'mandatory
true') so that a application level data model may 'refine'
it with an application specific default port number value.";
}
leaf local-address {
type inet:ip-address;
description
"The local IP address/interface (VRF?) to bind to for when
connecting to the remote peer. INADDR_ANY ('0.0.0.0') or
INADDR6_ANY ('0:0:0:0:0:0:0:0' a.k.a. '::') MAY be used to
explicitly indicate the implicit default, that the server
can bind to any IPv4 or IPv6 addresses, respectively.";
}
leaf local-port {
type inet:port-number;
default "0";
description
"The local IP port number to bind to for when connecting to
the remote peer. The port number '0', which is the default
value, indicates that any available local port number may
be used.";
}
}
grouping keepalives-grouping {
description
"A reusable grouping for configuring TCP client keepalive
parameters.";
container tcp-keepalives {
if-feature "tcp-client-keepalives";
description
"Configures the keep-alive policy, to proactively test the
aliveness of the TCP server. Not all clients will use
all the values, based on capabilities of the underlying
operating system. An unresponsive TCP server is dropped
after approximately (idle-time * 60) + (max-probes *
probe-interval) seconds.";
leaf idle-time {
type uint16 {
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range "1..max";
}
units "minutes";
description
"Sets the amount of time in minutes after which if no data
has been received from the TCP server, a TCP-level probe
message will be sent to test the aliveness of the TCP
server. When 'idle-time' is not configured (the default)
TCP keep-alives are disabled.";
}
leaf max-probes {
type uint16 {
range "1..max";
}
description
"Sets the maximum number of sequential keep-alive probes
that can fail to obtain a response from the TCP server
before assuming the TCP server is no longer alive. If
no value is specified, then the operating system provided
default value is used.";
}
leaf probe-interval {
type uint16 {
range "1..max";
}
units "seconds";
description
"Sets the time interval between failed probes. If no value
is specified, then the operating system provided default
value is used.";
}
}
}
}
4. The TCP Server Model
4.1. Tree Diagram
This section provides a tree diagram [RFC8340] for the "ietf-tcp-
server" module.
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module: ietf-tcp-server
grouping tcp-server-grouping
+-- local-address inet:ip-address
+-- local-port? inet:port-number
+-- tcp-keepalives {tcp-server-keepalives}?
+-- idle-time? uint16
+-- max-probes? uint16
+-- probe-interval? uint16
grouping ip-params-grouping
+-- local-address inet:ip-address
+-- local-port? inet:port-number
grouping keepalives-grouping
+-- tcp-keepalives {tcp-server-keepalives}?
+-- idle-time? uint16
+-- max-probes? uint16
+-- probe-interval? uint16
4.2. Example Usage
This section presents an example showing the tcp-server-grouping
populated with some data.
10.20.30.40
7777
15
3
30
4.3. YANG Module
This YANG module has normative references to [RFC6991].
file "ietf-tcp-server@2019-03-09.yang"
module ietf-tcp-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-tcp-server";
prefix tcps;
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
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organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen ";
description
"This module defines reusable groupings for TCP servers that
can be used as a basis for specific TCP server instances.
The key words '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.
Copyright (c) 2019 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 2019-03-09 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for TCP Clients and TCP Servers";
}
// Features
feature tcp-server-keepalives {
description
"Per socket TCP keepalive parameters are configurable for
TCP servers on the server implementing this feature.";
}
// Groupings
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grouping tcp-server-grouping {
description
"A reusable grouping for configuring a TCP server.";
uses ip-params-grouping;
uses keepalives-grouping;
}
grouping ip-params-grouping {
description
"A reusable grouping for configuring TCP server IP level
parameters.";
leaf local-address {
type inet:ip-address;
mandatory true;
description
"The local IP address to listen on for incoming TCL
client connections. INADDR_ANY (0.0.0.0) or INADDR6_ANY
(0:0:0:0:0:0:0:0 a.k.a. ::) MUST be used when the server
is to listen on all IPv4 or IPv6 addresses, respectively.";
}
leaf local-port {
type inet:port-number;
default "0";
description
"The local port number to listen on for incoming TCP client
connections. An invalid default value (0) is used (instead
of 'mandatory true') so that a application level data model
may 'refine' it with an application specific default port
number value.";
}
}
grouping keepalives-grouping {
description
"A reusable grouping for configuring TCP server keepalive
parameters.";
container tcp-keepalives {
if-feature "tcp-server-keepalives";
description
"Configures the keep-alive policy, to proactively test the
aliveness of the TCP client. Not all servers will use
all the values, based on capabilities of the underlying
operating system. An unresponsive TCP client is dropped
after approximately (idle-time * 60) + (max-probes *
probe-interval) seconds.";
leaf idle-time {
type uint16 {
range "1..max";
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}
units "minutes";
description
"Sets the amount of time in minutes after which if no data
has been received from the TCP client, a TCP-level probe
message will be sent to test the aliveness of the TCP
client. When 'idle-time' is not configured (the default)
TCP keep-alives are disabled.";
}
leaf max-probes {
type uint16 {
range "1..max";
}
description
"Sets the maximum number of sequential keep-alive probes
that can fail to obtain a response from the TCP client
before assuming the TCP client is no longer alive. If
no value is specified, then the operating system provided
default value is used.";
}
leaf probe-interval {
type uint16 {
range "1..max";
}
units "seconds";
description
"Sets the time interval between failed probes. If no value
is specified, then the operating system provided default
value is used.";
}
}
}
}
5. Security Considerations
The YANG modules defined in this document are designed to be accessed
via YANG based management protocols, such as NETCONF [RFC6241] and
RESTCONF [RFC8040]. Both of these protocols have mandatory-to-
implement secure transport layers (e.g., SSH, TCP) with mutual
authentication.
The NETCONF access control model (NACM) [RFC8341] provides the means
to restrict access for particular users to a pre-configured subset of
all available protocol operations and content.
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Since the modules defined in this document only define groupings,
these considerations are primarily for the designers of other modules
that use these groupings.
There are a number of data nodes defined in the YANG modules that are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
NONE
Some of the readable data nodes in the YANG modules may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data
nodes and their sensitivity/vulnerability:
NONE
Some of the RPC operations in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control access to these operations. These are the
operations and their sensitivity/vulnerability:
NONE
6. IANA Considerations
6.1. The IETF XML Registry
This document registers two URIs in the "ns" subregistry of the IETF
XML Registry [RFC3688]. Following the format in [RFC3688], the
following registrations are requested:
URI: urn:ietf:params:xml:ns:yang:ietf-tcp-client
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-tcp-server
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
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6.2. The YANG Module Names Registry
This document registers two YANG modules in the YANG Module Names
registry [RFC6020]. Following the format in [RFC6020], the following
registrations are requested:
name: ietf-tcp-client
namespace: urn:ietf:params:xml:ns:yang:ietf-tcp-client
prefix: tcpc
reference: RFC XXXX
name: ietf-tcp-server
namespace: urn:ietf:params:xml:ns:yang:ietf-tcp-server
prefix: tcps
reference: RFC XXXX
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,
.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, .
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
.
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7.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
.
[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,
.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
.
Author's Address
Kent Watsen
Watsen Networks
EMail: kent+ietf@watsen.net
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