RESTCONF Client and Server ModelsWatsen Networkskent+ietf@watsen.net
Operations
NETCONF Working GroupThis document defines two YANG modules,
one module to configure a RESTCONF client and the other module to
configure a RESTCONF server. Both modules support the TLS transport
protocol with both standard RESTCONF and RESTCONF Call Home connections.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.This document contains references to other drafts in progress, both in
the Normative References section, as well as in body text throughout.
Please update the following references to reflect their final RFC assignments:
I-D.ietf-netconf-keystoreI-D.ietf-netconf-tcp-client-serverI-D.ietf-netconf-tls-client-serverI-D.ietf-netconf-http-client-serverArtwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements:
XXXX --> the assigned RFC value for this draftAAAA --> the assigned RFC value for I-D.ietf-netconf-tcp-client-serverBBBB --> the assigned RFC value for I-D.ietf-netconf-tls-client-serverCCCC --> the assigned RFC value for I-D.ietf-netconf-http-client-serverArtwork in this document contains placeholder values for the date of publication of this
draft. Please apply the following replacement:
2020-03-08 --> the publication date of this draftThe following Appendix section is to be removed prior to publication:
. Change LogThis document defines two YANG modules,
one module to configure a RESTCONF client and the other module to
configure a RESTCONF server .
Both modules support the TLS transport
protocol with both standard RESTCONF and RESTCONF Call Home connections
.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
when, and only when, they appear in all capitals, as shown here.The RESTCONF client model presented in this section supports
both clients initiating connections to servers, as well as
clients listening for connections from servers calling home.YANG feature statements are used to enable implementations to
advertise which potentially uncommon parts of the model the
RESTCONF client supports.The following tree diagram provides an
overview of the data model for the "ietf-restconf-client" module.This tree diagram only shows the nodes defined in this module; it does
show the nodes defined by "grouping" statements used by this module.Please see for a tree
diagram that illustrates what the module looks like with all the
"grouping" statements expanded.The following example illustrates configuring a RESTCONF
client to initiate connections, as well as listening for call-home
connections.This example is consistent with the examples presented in
Section 2 of
and Section 3.2 of .corp-fw1corp-fw1.example.comcorp-fw1.example.com15330rsa2048ct:subject-public-key-info-fo\
rmatbase64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-server-ca-certs
trusted-server-ee-certs
303bobsecretcorp-fw2.example.comcorp-fw2.example.com15330rsa2048ct:subject-public-key-info-fo\
rmatbase64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-server-ca-certs
trusted-server-ee-certs
303bobsecretIntranet-facing listener11.22.33.44rsa2048ct:subject-public-key-info-format\
base64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-server-ca-certs
trusted-server-ee-certs
bobsecret
]]>This YANG module has normative references to ,
, and ,
,
, and
.<CODE BEGINS> file "ietf-restconf-client@2020-03-08.yang"
WG List:
Author: Kent Watsen
Author: Gary Wu ";
description
"This module contains a collection of YANG definitions
for configuring RESTCONF clients.
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 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature https-initiate {
description
"The 'https-initiate' feature indicates that the RESTCONF
client supports initiating HTTPS connections to RESTCONF
servers. This feature exists as HTTPS might not be a
mandatory to implement transport in the future.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature http-listen {
description
"The 'https-listen' feature indicates that the RESTCONF client
supports opening a port to listen for incoming RESTCONF
server call-home connections. This feature exists as not
all RESTCONF clients may support RESTCONF call home.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature https-listen {
description
"The 'https-listen' feature indicates that the RESTCONF client
supports opening a port to listen for incoming RESTCONF
server call-home connections. This feature exists as not
all RESTCONF clients may support RESTCONF call home.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// Groupings
grouping restconf-client-grouping {
description
"A reusable grouping for configuring a RESTCONF client
without any consideration for how underlying transport
sessions are established.
This grouping currently doesn't define any nodes.";
}
grouping restconf-client-initiate-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF client
'initiate' protocol stack for a single connection.";
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-initiate";
container https {
description
"Specifies HTTPS-specific 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 "443";
description
"The RESTCONF client will attempt to
connect to the IANA-assigned well-known
port value for 'https' (443) if no value
is specified.";
}
}
}
container tls-client-parameters {
must 'client-identity' {
description
"NETCONF/TLS clients MUST pass some
authentication credentials.";
}
description
"A wrapper around the TLS client parameters
to avoid name collisions.";
uses tlsc:tls-client-grouping;
}
container http-client-parameters {
description
"A wrapper around the HTTP client parameters
to avoid name collisions.";
uses httpc:http-client-grouping;
}
container restconf-client-parameters {
description
"A wrapper around the HTTP client parameters
to avoid name collisions.";
uses rcc:restconf-client-grouping;
}
}
}
}
} // restconf-client-initiate-stack-grouping
grouping restconf-client-listen-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF client
'listen' protocol stack for a single connection.";
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 http {
if-feature "http-listen";
container FIXME {
description
"FIXME";
}
}
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 client parameters
to avoid name collisions.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "4336";
description
"The RESTCONF client will listen on the IANA-
assigned well-known port for 'restconf-ch-tls'
(4336) if no value is specified.";
}
}
}
container tls-client-parameters {
must 'client-identity' {
description
"NETCONF/TLS clients MUST pass some
authentication credentials.";
}
description
"A wrapper around the TLS client parameters
to avoid name collisions.";
uses tlsc:tls-client-grouping;
}
container http-client-parameters {
description
"A wrapper around the HTTP client parameters
to avoid name collisions.";
uses httpc:http-client-grouping;
}
container restconf-client-parameters {
description
"A wrapper around the RESTCONF client parameters
to avoid name collisions.";
uses rcc:restconf-client-grouping;
}
}
}
}
} // restconf-client-listen-stack-grouping
grouping restconf-client-app-grouping {
description
"A reusable grouping for configuring a RESTCONF client
application that supports both 'initiate' and 'listen'
protocol stacks for a multiplicity of connections.";
container initiate {
if-feature "https-initiate";
presence "Enables client to initiate TCP connections";
description
"Configures client initiating underlying TCP connections.";
list restconf-server {
key "name";
min-elements 1;
description
"List of RESTCONF servers the RESTCONF client is to
maintain simultaneous connections with.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF server.";
}
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
RESTCONF client 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.";
}
uses restconf-client-initiate-stack-grouping;
}
}
container connection-type {
description
"Indicates the RESTCONF client'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 server. If the connection goes down,
immediately start trying to reconnect to the
RESTCONF server, using the reconnection strategy.
This connection type minimizes any RESTCONF server
to RESTCONF client 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 server.
This connection type increases resource
utilization, albeit with increased delay
in RESTCONF server to RESTCONF client
interactions.
The RESTCONF client SHOULD gracefully close
the underlying TLS connection upon completing
planned activities.
In the case that the previous connection is
still active, 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
RESTCONF client will never drop a session
because it is idle.";
}
}
} // periodic-connection
} // connection-type
} // connection-type
container reconnect-strategy {
description
"The reconnection strategy directs how a RESTCONF
client reconnects to a RESTCONF server, after
discovering its connection to the server has
dropped, even if due to a reboot. The RESTCONF
client 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 clients
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 server's
endpoints the RESTCONF client should start
with when trying to connect to the RESTCONF
server.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default "3";
description
"Specifies the number times the RESTCONF client
tries to connect to a specific endpoint before
moving on to the next endpoint in the list
(round robin).";
}
}
}
} // initiate
container listen {
if-feature "http-listen or https-listen";
presence "Enables client to accept call-home connections";
description
"Configures client accepting call-home TCP connections.";
leaf idle-timeout {
type uint16;
units "seconds";
default 3600; // one hour
description
"Specifies the maximum number of seconds that an
underlying TCP session may remain idle. A TCP session
will be dropped if it is idle for an interval longer
then 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 RESTCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the RESTCONF listen endpoint.";
}
uses restconf-client-listen-stack-grouping;
}
}
} // restconf-client-app-grouping
// Protocol accessible node, for servers that implement this
// module.
container restconf-client {
uses restconf-client-app-grouping;
description
"Top-level container for RESTCONF client configuration.";
}
}
]]><CODE ENDS>The RESTCONF server model presented in this section supports
both listening for connections as well as initiating call-home
connections.YANG feature statements are used to enable implementations to
advertise which potentially uncommon parts of the model the
RESTCONF server supports.The following tree diagram provides an
overview of the data model for the "ietf-restconf-server" module.This tree diagram only shows the nodes defined in this module; it does
show the nodes defined by "grouping" statements used by this module.Please see for a tree
diagram that illustrates what the module looks like with all the
"grouping" statements expanded.The following example illustrates configuring a RESTCONF server
to listen for RESTCONF client connections, as well as configuring
call-home to one RESTCONF client.This example is consistent with the examples presented in
Section 2 of
and Section 3.2 of .netconf/tls11.22.33.44rsa2048ct:subject-public-key-info-format\
base64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-client-ca-certs
trusted-client-ee-certs
foo.example.comHTTP/1.1HTTP/2.0111:0A:05:11:00x509c2n:specifiedscooby-doo2x509c2n:san-anyconfig-managereast-data-centereast.example.comrsa2048ct:subject-public-key-info-fo\
rmatbase64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-client-ca-certs
trusted-client-ee-certs
foo.example.comHTTP/1.1HTTP/2.0111:0A:05:11:00x509c2n:specifiedscooby-doo2x509c2n:san-anywest-data-centerwest.example.comrsa2048ct:subject-public-key-info-fo\
rmatbase64encodedvalue==ct:rsa-private-key-format
base64encodedvalue==base64encodedvalue==trusted-client-ca-certs
trusted-client-ee-certs
foo.example.comHTTP/1.1HTTP/2.0111:0A:05:11:00x509c2n:specifiedscooby-doo2x509c2n:san-any30060last-connected3
]]>This YANG module has normative references to ,
, , ,
,
, and
.<CODE BEGINS> file "ietf-restconf-server@2020-03-08.yang"
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 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: RESTCONF Client and Server Models";
}
// Features
feature http-listen {
description
"The 'http-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF over
TPC client connections, whereby the TLS connections are
terminated by an external system.";
reference
"RFC 8040: RESTCONF Protocol";
}
feature https-listen {
description
"The 'https-listen' feature indicates that the RESTCONF server
supports opening a port to listen for incoming RESTCONF over
TLS client connections, whereby the TLS connections are
terminated by the server itself.";
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.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// Groupings
grouping restconf-server-grouping {
description
"A reusable grouping for configuring a RESTCONF server
without any consideration for how underlying transport
sessions are established.
Note that this grouping uses a fairly typical descendent
node name such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue by wrapping the 'uses'
statement in a container called, e.g.,
'restconf-server-parameters'. This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container client-identity-mappings {
//if-feature "client-certificates-supported"; // FIXME: yes?
description
"Specifies mappings through which RESTCONF client X.509
certificates are used to determine 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.";
uses x509c2n:cert-to-name {
refine "cert-to-name/fingerprint" {
mandatory false;
description
"A 'fingerprint' value does not need to be specified
when the 'cert-to-name' mapping is independent of
fingerprint matching. A 'cert-to-name' having no
fingerprint value will match any client certificate
and therefore should only be present at the end of
the user-ordered 'cert-to-name' list.";
}
}
}
}
grouping restconf-server-listen-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF server
'listen' protocol stack for a single connection.";
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 http {
if-feature "http-listen";
container http {
description
"Configures RESTCONF server stack assuming that
TLS-termination is handled externally.";
container external-endpoint {
presence
"Specifies configuration for an external endpoint.";
description
"Identifies contact information for the external
system that terminates connections before passing
them thru to this server (e.g., a network address
translator or a load balancer). These values have
no effect on the local operation of this server, but
may be used by the application when needing to
inform other systems how to contact this server.";
leaf address {
type inet:ip-address;
mandatory true;
description
"The IP address or hostname of the external system
that terminates incoming RESTCONF client
connections before forwarding them to this
server.";
}
leaf port {
type inet:port-number;
default "443";
description
"The port number that the external system listens
on for incoming RESTCONF client connections that
are forwarded to this server. The default HTTPS
port (443) is used, as expected for a RESTCONF
connection.";
}
}
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 "80";
description
"The RESTCONF server will listen on the IANA-
assigned well-known port value for 'http'
(80) if no value is specified.";
}
}
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
case https {
if-feature "https-listen";
container https {
description
"Configures RESTCONF server stack assuming that
TLS-termination is handled internally.";
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;
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
}
}
grouping restconf-server-callhome-stack-grouping {
description
"A reusable grouping for configuring a RESTCONF server
'call-home' protocol stack, for a single connection.";
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
"Configures RESTCONF server stack assuming that
TLS-termination is handled internally.";
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; /* {
FIXME: commented out since auth could also be external.
^-- need a better 'must' expression?
refine "client-authentication" {
must 'ca-certs or client-certs';
description
"NETCONF/TLS servers MUST validate client
certificates.";
}*/
}
container http-server-parameters {
description
"A wrapper around the HTTP server parameters
to avoid name collisions.";
uses https:http-server-grouping;
}
container restconf-server-parameters {
description
"A wrapper around the RESTCONF server parameters
to avoid name collisions.";
uses rcs:restconf-server-grouping;
}
}
}
}
}
grouping restconf-server-app-grouping {
description
"A reusable grouping for configuring a RESTCONF server
application that supports both 'listen' and 'call-home'
protocol stacks for a multiplicity of connections.";
container listen {
if-feature "http-listen or 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.";
}
uses restconf-server-listen-stack-grouping;
}
}
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
maintain simultaneous call-home connections with.";
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.";
}
uses restconf-server-callhome-stack-grouping;
}
}
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-app-grouping
// Protocol accessible node, for servers that implement this
// module.
container restconf-server {
uses restconf-server-app-grouping;
description
"Top-level container for RESTCONF server configuration.";
}
}
]]><CODE ENDS>The YANG module defined in this document uses groupings defined in
,
, and
. Please
see the Security Considerations section in those documents for
concerns related those groupings.The YANG modules defined in this document are designed to be accessed
via YANG based management protocols, such as NETCONF
and RESTCONF . Both of these protocols have
mandatory-to-implement secure transport layers (e.g., SSH, TLS) with
mutual authentication.The NETCONF access control model (NACM)
provides the means to restrict access for particular users to a
pre-configured subset of all available protocol operations and content.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).
Some of 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:
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:
Some of the RPC operations in the YANG modules 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:
This document registers two URIs in the "ns" subregistry of the IETF XML
Registry . Following the format in
, the following registrations are
requested:This document registers two YANG modules in the
YANG Module Names registry .
Following the format in , the
the following registrations are requested:The following tree diagram provides an
overview of the data model for the "ietf-restconf-client" module.This tree diagram shows all the nodes defined in this module,
including those defined by "grouping" statements used by this module.Please see for a tree
diagram that illustrates what the module looks like without
all the "grouping" statements expanded.The following tree diagram provides an
overview of the data model for the "ietf-restconf-server" module.This tree diagram shows all the nodes defined in this module,
including those defined by "grouping" statements used by this module.Please see for a tree
diagram that illustrates what the module looks like without
all the "grouping" statements expanded.Renamed "keychain" to "keystore".Filled in previously missing 'ietf-restconf-client' module.Updated the ietf-restconf-server module to accommodate new
grouping 'ietf-tls-server-grouping'.Refined use of tls-client-grouping to add a must statement
indicating that the TLS client must specify a client-certificate.Changed restconf-client??? to be a grouping (not a container).Added RFC 8174 to Requirements Language Section.Replaced refine statement in ietf-restconf-client
to add a mandatory true.Added refine statement in ietf-restconf-server
to add a must statement.Now there are containers and groupings, for both the
client and server models.Now tree diagrams reference ietf-netmod-yang-tree-diagramsUpdated examples to inline key and certificates (no longer
a leafref to keystore)Now tree diagrams reference ietf-netmod-yang-tree-diagramsUpdated examples to inline key and certificates (no longer
a leafref to keystore)Fixed change log missing section issue.Updated examples to match latest updates to the crypto-types,
trust-anchors, and keystore drafts.Reduced line length of the YANG modules to fit within 69 columns.removed "idle-timeout" from "persistent" connection config.Added "random-selection" for reconnection-strategy's "starts-with" enum.Replaced "connection-type" choice default (persistent) with "mandatory true".Reduced the periodic-connection's "idle-timeout" from 5 to 2 minutes.Replaced reconnect-timeout with period/anchor-time combo.Modified examples to be compatible with new crypto-types algsCorrected use of "mandatory true" for "address" leafs.Updated examples to reflect update to groupings defined in the keystore draft.Updated to use groupings defined in new TCP and HTTP drafts.Updated copyright date, boilerplate template, affiliation, and folding algorithm.Reformatted YANG modules.Adjusted for the top-level "demux container" added to groupings
imported from other modules.Added "must" expressions to ensure that keepalives are not configured
for "periodic" connections.Updated the boilerplate text in module-level "description" statement
to match copyeditor convention.Moved "expanded" tree diagrams to the Appendix.Removed the 'must' statement limiting keepalives in periodic
connections.Updated models and examples to reflect removal of the "demux"
containers in the imported models.Updated the "periodic-connnection" description statements to
better describe behavior when connections are not closed
gracefully.Updated text to better reference where certain examples come from
(e.g., which Section in which draft).In the server model, commented out the "must 'pinned-ca-certs or
pinned-client-certs'" statement to reflect change made in the
TLS draft whereby the trust anchors MAY be defined externally.Replaced the 'listen', 'initiate', and 'call-home' features
with boolean expressions.Updated to reflect changes in trust-anchors drafts
(e.g., s/trust-anchors/truststore/g + s/pinned.//)In ietf-restconf-server, Added 'http-listen' (not https-listen) choice, to support
case when server is behind a TLS-terminator.Refactored server module to be more like other 'server' models. If folks like it, will
also apply to the client model, as well as to both the netconf client/server models. Now
the 'restconf-server-grouping' is just the RC-specific bits (i.e., the "demux" container
minus the container), 'restconf-server-[listen|callhome]-stack-grouping' is the protocol
stack for a single connection, and 'restconf-server-app-grouping' is effectively what
was before (both listen+callhome for many inbound/outbound endpoints).Updated examples to reflect ietf-crypto-types change
(e.g., identities --> enumerations)Adjusting from change in TLS client model (removing the top-level
'certificate' container).Added "external-endpoint" to the "http-listen" choice in ietf-restconf-server.Added missing "or https-listen" clause in a "must" expression.Refactored the client module similar to how the server module was refactored in -13. Now
the 'restconf-client-grouping' is just the RC-specific bits, the
'restconf-client-[initiate|listen]-stack-grouping' is the protocol
stack for a single connection, and 'restconf-client-app-grouping' is effectively what
was before (both listen+callhome for many inbound/outbound endpoints).Added refinement to make "cert-to-name/fingerprint" be mandatory false.Commented out refinement to "tls-server-grouping/client-authentication"
until a better "must" expression is defined.Updated restconf-client example to reflect that http-client-grouping no
longer has a "protocol-version" leaf.Updated examples to include the "*-key-format" nodes.Updated examples to remove the "required" nodes.Updated examples to reflect new "bag" addition to truststore.The authors would like to thank for following for
lively discussions on list and in the halls (ordered
by first name):
Alan Luchuk,
Andy Bierman,
Balázs Kovács,
Benoit Claise,
Bert Wijnen
David Lamparter,
Juergen Schoenwaelder,
Ladislav Lhotka,
Martin Bjorklund,
Mehmet Ersue,
Phil Shafer,
Radek Krejci,
Ramkumar Dhanapal,
Sean Turner,
and
Tom Petch.