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-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-tls-server {
prefix tlss;
reference
"RFC BBBB: YANG Groupings for TLS Clients and TLS Servers";
}
import ietf-http-server {
prefix https;
reference
"RFC CCCC: YANG Groupings for HTTP Clients and HTTP 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) 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 2019-04-29 {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature https-listen {
description
"The 'https-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF
client connections. This feature exists as HTTPS might not
be a mandatory to implement transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature https-call-home {
description
"The 'https-call-home' feature indicates that the RESTCONF
server supports initiating connections to RESTCONF clients.
This feature exists as not all RESTCONF servers may
support RESTCONF call home.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// Groupings
grouping restconf-server-grouping {
description
"Top-level grouping for RESTCONF server configuration.";
container listen {
if-feature "https-listen";
presence
"Enables the RESTCONF server to listen for RESTCONF
client 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 https {
if-feature "https-listen";
container https {
description
"HTTPS-specific listening configuration for inbound
connections.";
container tcp-server-parameters {
description
"A wrapper around the TCP server parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "443";
description
"The RESTCONF server will listen on the IANA-
assigned well-known port value for 'https'
(443) 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 'pinned-ca-certs or pinned-client-certs';
//presence "Enables TLS-level authentication
// using client certificates.";
description
"RESTCONF servers MUST be able to validate
clients.";
}
*/
augment
"client-authentication/local-or-external/local" {
description
"Augments in the cert-to-name structure,
so the RESTCONF server can map TLS-layer
client certificates to RESTCONF usernames.";
container cert-maps {
/*must '../pinned-ca-certs
or ../pinned-client-certs'; */
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.";
}
//leaf optional {
// type empty;
//}
}
}
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
/* {
augment "http-server-parameters" { // HELP!!!
description
"Augments in a flag indicating that the
RESCONF server MUST authenticate the
RESTCONF client using the HTTP 'basic'
authentication scheme. How the RESTCONF
server defines users and passwords is
outside the scope of this data model.";
container client-authentication {
leaf optional {
type empty;
}
choice configured-or-external {
mandatory true;
case external {
leaf user-auth-defined-elsewhere {
type empty;
}
}
}
}
}
}
*/
}
} // https container
} // tls case
} // transport
} // endpoint
} // listen
container call-home {
if-feature "https-call-home";
presence
"Enables the RESTCONF server to initiate the underlying
transport connection to RESTCONF clients.";
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 https {
if-feature "https-call-home";
container https {
description
"Specifies HTTPS-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 "4336";
description
"The RESTCONF server will attempt to
connect to the IANA-assigned well-known
port for 'restconf-ch-tls' (4336) 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 'pinned-ca-certs
or pinned-client-certs'; */
description
"RESTCONF servers MUST be able to validate
clients.";
}
augment "client-authentication" {
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.";
}
}
}
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
}
}
} // transport
} // endpoint
} // endpoints
container connection-type {
description
"Indicates the RESTCONF server's preference for how the
RESTCONF 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 the RESTCONF server,
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.";
}
}
case periodic-connection {
container periodic {
presence "Indicates that a periodic connection is
to be maintained.";
description
"Periodically connect to the RESTCONF client.
This connection type increases resource
utilization, albeit with increased delay in
RESTCONF client to RESTCONF client interactions.
The RESTCONF client SHOULD gracefully close
the underlying TLS connection upon completing
planned activities. If the underlying TLS
connection is not closed gracefully, the
RESTCONF server MUST immediately attempt
to reestablish the connection.
In the case that the previous connection is
still active (i.e., the RESTCONF 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
the underlying TCP session may remain idle.
A TCP 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).";
}
}
} // restconf-client
} // call-home
} // restconf-server-grouping
// Protocol accessible node, for servers that implement this
// module.
container restconf-server {
uses restconf-server-grouping;
description
"Top-level container for RESTCONF server configuration.";
}
}