module ietf-restconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-restconf-server";
prefix "rcs";
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-x509-cert-to-name {
prefix x509c2n;
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-tls-server {
prefix ts;
revision-date 2018-09-20; // stable grouping definitions
reference
"RFC ZZZZ: 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 RESTCONF servers.
Copyright (c) 2017 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 "2018-09-20" {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature listen {
description
"The 'listen' feature indicates that the RESTCONF server
supports opening a port to accept RESTCONF client connections
using at least one transport (e.g., TLS, etc.).";
}
feature tls-listen {
if-feature listen;
description
"The 'tls-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF
client connections. This feature exists as TLS might not
be a mandatory to implement transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature call-home {
description
"The 'call-home' feature indicates that the RESTCONF
server supports initiating RESTCONF call home connections
to RESTCONF clients using at least one transport (e.g.,
TLS, etc.).";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-call-home {
if-feature call-home;
description
"The 'tls-call-home' feature indicates that the RESTCONF
server supports initiating connections to RESTCONF clients.
This feature exists as TLS might not be a mandatory to
implement transport in the future.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
container restconf-server {
uses restconf-server-grouping;
description
"Top-level container for RESTCONF server configuration.";
}
grouping restconf-server-grouping {
description
"Top-level grouping for RESTCONF server configuration.";
container listen {
if-feature listen;
presence "Enables server to listen for TCP connections";
description "Configures listen behavior";
list endpoint {
key name;
min-elements 1;
description
"List of endpoints to listen for RESTCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF listen endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-listen;
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
description
"The IP address to listen on for incoming
connections. The RESTCONF server will listen
on all configured interfaces if no value is
specified. 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 port {
type inet:port-number;
default 443;
description
"The local port number to listen on. If no value
is specified, the IANA-assigned port value for
'https' (443) is used.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"RESTCONF servers MUST be able to validate
clients.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure,
so the RESTCONF server can map TLS-layer
client certificates to RESTCONF usernames.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a TLS-
based RESTCONF server to map the RESTCONF
client's presented X.509 certificate to
a RESTCONF username. If no matching and
valid cert-to-name list entry can be found,
then the RESTCONF server MUST close the
connection, and MUST NOT accept RESTCONF
messages over it.";
reference
"RFC 7407: A YANG Data Model for SNMP
Configuration.";
}
}
}
} // end tls container
} // end tls case
} // end transport
} // end endpoint
} // end listen
container call-home {
if-feature call-home;
presence "Enables server to initiate TCP connections";
description "Configures call-home behavior";
list restconf-client {
key name;
min-elements 1;
description
"List of RESTCONF clients the RESTCONF server is to
initiate call-home connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the remote RESTCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key name;
min-elements 1;
ordered-by user;
description
"User-ordered list of endpoints for this RESTCONF
client. 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. This is a
'choice' statement so as to support additional
transport options to be augmented in.";
case tls {
if-feature tls-call-home;
container tls {
description
"Specifies TLS-specific call-home transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the DNS resolution results in
multiple IP addresses, the IP addresses will
be tried according to local preference order
until a connection has been established or
until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 4336;
description
"The IP port for this endpoint. The RESTCONF
server will use the IANA-assigned well-known
port for 'restconf-ch-tls' (4336) if no value
is specified.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"RESTCONF servers MUST be able to validate
clients.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure,
so the RESTCONF server can map TLS-layer
client certificates to RESTCONF usernames.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a
TLS-based RESTCONF server to map the
RESTCONF client's presented X.509
certificate to a RESTCONF username. If
no matching and valid cert-to-name list
entry can be found, then the RESTCONF
server MUST close the connection, and
MUST NOT accept RESTCONF messages over
it.";
reference
"RFC 7407: A YANG Data Model for SNMP
Configuration.";
}
}
}
}
}
} // end transport
} // end endpoint
} // end endpoints
container connection-type {
description
"Indicates the RESTCONF client's preference for how the
RESTCONF server's 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 RESTCONF
client. If the connection goes down, immediately
start trying to reconnect to it, using the
reconnection strategy.
This connection type minimizes any RESTCONF
client to RESTCONF server data-transfer delay,
albeit at the expense of holding resources
longer.";
container keep-alives {
description
"Configures the keep-alive policy, to
proactively test the aliveness of the TLS
client. An unresponsive TLS client will
be dropped after approximately (max-attempts
* max-wait) seconds.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF
Call Home, Section 4.1, item S7";
leaf max-wait {
type uint16 {
range "1..max";
}
units seconds;
default 30;
description
"Sets the amount of time in seconds after
which if no data has been received from
the TLS client, a TLS-level message will
be sent to test the aliveness of the TLS
client.";
}
leaf max-attempts {
type uint8;
default 3;
description
"Sets the maximum number of sequential keep-
alive messages that can fail to obtain a
response from the TLS client before assuming
the TLS client is no longer alive.";
}
}
}
}
case periodic-connection {
container periodic {
presence
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the RESTCONF client. The
RESTCONF client should close the underlying TLS
connection upon completing planned activities.
This connection type increases resource
utilization, albeit with increased delay in
RESTCONF client to RESTCONF client interactions.";
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
the underlying TLS session may remain idle.
A TLS 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 reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF server
reconnects to a RESTCONF client after discovering its
connection to the client has dropped, even if due to a
reboot. The RESTCONF 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. RESTCONF
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 RESTCONF client's endpoints
the RESTCONF server should start with when trying
to connect to the RESTCONF client.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default 3;
description
"Specifies the number times the RESTCONF server tries
to connect to a specific endpoint before moving on to
the next endpoint in the list (round robin).";
}
}
}
}
}
}