module ietf-netconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server";
prefix ncs;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-x509-cert-to-name {
prefix x509c2n;
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-tcp-client {
prefix tcpc;
reference
"RFC AAAA: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tcp-server {
prefix tcps;
reference
"RFC AAAA: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-ssh-server {
prefix sshs;
revision-date 2019-07-02; // stable grouping definitions
reference
"RFC BBBB: YANG Groupings for SSH Clients and SSH Servers";
}
import ietf-tls-server {
prefix tlss;
revision-date 2019-07-02; // stable grouping definitions
reference
"RFC CCCC: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen
Author: Gary Wu
Author: Juergen Schoenwaelder
";
description
"This module contains a collection of YANG definitions
for configuring NETCONF servers.
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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.;
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 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2019-07-02 {
description
"Initial version";
reference
"RFC XXXX: NETCONF Client and Server Models";
}
// Features
feature ssh-listen {
description
"The 'ssh-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over SSH
client connections.";
reference
"RFC 6242:
Using the NETCONF Protocol over Secure Shell (SSH)";
}
feature tls-listen {
description
"The 'tls-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over TLS
client connections.";
reference
"RFC 7589: Using the NETCONF Protocol over Transport
Layer Security (TLS) with Mutual X.509
Authentication";
}
feature ssh-call-home {
description
"The 'ssh-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over SSH call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-call-home {
description
"The 'tls-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over TLS call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// Groupings
grouping netconf-server-grouping {
description
"Top-level grouping for NETCONF server configuration.";
container listen {
if-feature "ssh-listen or tls-listen";
presence
"Enables server to listen for NETCONF client connections.";
description
"Configures listen behavior";
leaf idle-timeout {
type uint16;
units "seconds";
default 3600; // one hour
description
"Specifies the maximum number of seconds that a NETCONF
session may remain idle. A NETCONF session will be
dropped if it is idle for an interval longer than this
number of seconds. If set to zero, then the server
will never drop a session because it is idle. Sessions
that have a notification subscription active are never
dropped.";
}
list endpoint {
key "name";
min-elements 1;
description
"List of endpoints to listen for NETCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the NETCONF listen endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-listen";
container ssh {
description
"SSH-specific listening configuration for inbound
connections.";
container tcp-server-parameters {
description
"A wrapper around the TCP client parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "830";
description
"The NETCONF server will listen on the
IANA-assigned well-known port value
for 'netconf-ssh' (830) if no value
is specified.";
}
}
}
container ssh-server-parameters {
description
"A wrapper around the SSH server parameters
to avoid name collisions.";
uses sshs:ssh-server-grouping;
}
}
}
case tls {
if-feature "tls-listen";
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
container tcp-server-parameters {
description
"A wrapper around the TCP client parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "6513";
description
"The NETCONF server will listen on the
IANA-assigned well-known port value
for 'netconf-tls' (6513) if no value
is specified.";
}
}
}
container tls-server-parameters {
description
"A wrapper around the TLS server parameters to
avoid name collisions.";
uses tlss:tls-server-grouping {
refine "client-authentication" {
//must 'ca-certs or client-certs';
description
"NETCONF/TLS servers MUST validate client
certificates.";
}
augment "client-authentication" {
description
"Augments in the cert-to-name structure.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a TLS-
based NETCONF server to map the NETCONF
client's presented X.509 certificate to
a NETCONF username. If no matching and
valid cert-to-name list entry can be found,
then the NETCONF server MUST close the
connection, and MUST NOT accept NETCONF
messages over it.";
reference
"RFC WWWW: NETCONF over TLS, Section 7";
}
}
}
}
}
}
}
}
}
container call-home {
if-feature "ssh-call-home or tls-call-home";
presence
"Enables the NETCONF server to initiate the underlying
transport connection to NETCONF clients.";
description "Configures call home behavior.";
list netconf-client {
key "name";
min-elements 1;
description
"List of NETCONF clients the NETCONF server is to
initiate call-home connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the remote NETCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key "name";
min-elements 1;
ordered-by user;
description
"A non-empty user-ordered list of endpoints for this
NETCONF server to try to connect to in sequence.
Defining more than one enables high-availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-call-home";
container ssh {
description
"Specifies SSH-specific call-home transport
configuration.";
container tcp-client-parameters {
description
"A wrapper around the TCP client parameters
to avoid name collisions.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "4334";
description
"The NETCONF server will attempt to connect
to the IANA-assigned well-known port for
'netconf-ch-tls' (4334) if no value is
specified.";
}
}
}
container ssh-server-parameters {
description
"A wrapper around the SSH server parameters
to avoid name collisions.";
uses sshs:ssh-server-grouping;
}
}
}
case tls {
if-feature "tls-call-home";
container tls {
description
"Specifies TLS-specific call-home transport
configuration.";
container tcp-client-parameters {
description
"A wrapper around the TCP client parameters
to avoid name collisions.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "4335";
description
"The NETCONF server will attempt to connect
to the IANA-assigned well-known port for
'netconf-ch-tls' (4335) if no value is
specified.";
}
}
}
container tls-server-parameters {
description
"A wrapper around the TLS server parameters
to avoid name collisions.";
uses tlss:tls-server-grouping {
refine "client-authentication" {
/* commented out since auth could be external
must 'ca-certs or client-certs';
*/
description
"NETCONF/TLS servers MUST validate client
certificates.";
}
augment "client-authentication" {
description
"Augments in the cert-to-name structure.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a
TLS-based NETCONF server to map the
NETCONF client's presented X.509
certificate to a NETCONF username. If
no matching and valid cert-to-name list
entry can be found, then the NETCONF
server MUST close the connection, and
MUST NOT accept NETCONF messages over
it.";
reference
"RFC WWWW: NETCONF over TLS, Section 7";
}
}
}
}
}
} // tls
} // choice
} // endpoint
} // endpoints
container connection-type {
description
"Indicates the NETCONF server's preference for how the
NETCONF connection is maintained.";
choice connection-type {
mandatory true;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence "Indicates that a persistent connection is
to be maintained.";
description
"Maintain a persistent connection to the NETCONF
client. If the connection goes down, immediately
start trying to reconnect to the NETCONF client,
using the reconnection strategy.
This connection type minimizes any NETCONF client
to NETCONF server data-transfer delay, albeit at
the expense of holding resources longer.";
} // container persistent
} // case persistent-connection
case periodic-connection {
container periodic {
presence "Indicates that a periodic connection is
to be maintained.";
description
"Periodically connect to the NETCONF client.
This connection type increases resource
utilization, albeit with increased delay in
NETCONF client to NETCONF client interactions.
The NETCONF client SHOULD gracefully close the
connection using upon completing
planned activities. If the NETCONF session is
not closed gracefully, the NETCONF server MUST
immediately attempt to reestablish the connection.
In the case that the previous connection is still
active (i.e., the NETCONF client has not closed
it yet), establishing a new connection is NOT
RECOMMENDED.";
leaf period {
type uint16;
units "minutes";
default "60";
description
"Duration of time between periodic connections.";
}
leaf anchor-time {
type yang:date-and-time {
// constrained to minute-level granularity
pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}'
+ '(Z|[\+\-]\d{2}:\d{2})';
}
description
"Designates a timestamp before or after which a
series of periodic connections are determined.
The periodic connections occur at a whole
multiple interval from the anchor time. For
example, for an anchor time is 15 minutes past
midnight and a period interval of 24 hours, then
a periodic connection will occur 15 minutes past
midnight everyday.";
}
leaf idle-timeout {
type uint16;
units "seconds";
default 120; // two minutes
description
"Specifies the maximum number of seconds that
a NETCONF session may remain idle. A NETCONF
session will be dropped if it is idle for an
interval longer than this number of seconds.
If set to zero, then the server will never
drop a session because it is idle.";
}
} // container periodic
} // case periodic-connection
} // choice connection-type
} // container connection-type
container reconnect-strategy {
description
"The reconnection strategy directs how a NETCONF server
reconnects to a NETCONF client, after discovering its
connection to the client has dropped, even if due to a
reboot. The NETCONF server starts with the specified
endpoint and tries to connect to it max-attempts times
before trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. NETCONF
servers SHOULD be able to remember the last
endpoint connected to across reboots.";
}
enum random-selection {
description
"Indicates that reconnections should start with
a random endpoint.";
}
}
default "first-listed";
description
"Specifies which of the NETCONF client's endpoints
the NETCONF server should start with when trying
to connect to the NETCONF client.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default "3";
description
"Specifies the number times the NETCONF server tries
to connect to a specific endpoint before moving on
to the next endpoint in the list (round robin).";
}
} // container reconnect-strategy
} // list netconf-client
} // container call-home
} // grouping netconf-server-grouping
// Protocol accessible node, for servers that implement this
// module.
container netconf-server {
uses netconf-server-grouping;
description
"Top-level container for NETCONF server configuration.";
}
}