module ietf-netconf-server { namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server"; prefix "ncserver"; import ietf-netconf-acm { prefix nacm; // RFC 6536 revision-date 2012-02-22; } import ietf-inet-types { // RFC 6991 prefix inet; revision-date 2013-07-15; } import ietf-x509-cert-to-name { // RFC 7407 prefix x509c2n; revision-date 2014-12-10; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: WG Chair: Mehmet Ersue WG Chair: Mahesh Jethanandani Editor: Kent Watsen "; description "This module contains a collection of YANG definitions for configuring NETCONF servers. Copyright (c) 2014 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 VVVV; see the RFC itself for full legal notices."; revision "2015-02-02" { description "Initial version"; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models"; } // Features feature ssh { description "The ssh feature indicates that the server supports the SSH transport protocol."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)"; } feature tls { description "The tls feature indicates that the server supports the TLS transport protocol."; reference "RFC 5539: NETCONF over Transport Layer Security (TLS)"; } feature listen { description "The listen feature indicates that the server supports opening a port to listen for incoming client connections."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH) RFC 5539: NETCONF over Transport Layer Security (TLS)"; } feature call-home { description "The call-home feature indicates that the server supports connecting to the client"; reference "RFC YYYY: NETCONF Call Home and RESTCONF Call Home"; } feature ssh-x509-certs { description "The ssh-x509-certs feature indicates that the NETCONF server supports RFC 6187"; reference "RFC 6187: X.509v3 Certificates for Secure Shell Authentication"; } // top-level container (groupings below) container netconf-server { description "Top-level container for NETCONF server configuration."; uses session-options-container; uses listen-container; uses call-home-container; uses ssh-container; uses tls-container; } grouping session-options-container { description "This grouping is used only to help improve readability of the YANG module."; container session-options { description "NETCONF session options, independent of transport or connection strategy."; leaf hello-timeout { type uint32 { range "0 | 10 .. 3600"; } units "seconds"; default '600'; description "Specifies the number of seconds that a session may exist before the hello PDU is received. A session will be dropped if no hello PDU is received before this number of seconds elapses. If this parameter is set to zero, then the server will wait forever for a hello message, and not drop any sessions stuck in 'hello-wait' state. Setting this parameter to zero may permit denial of service attacks, since only a limited number of concurrent sessions may be supported by the server."; } leaf idle-timeout { type uint32 { range "0 | 10 .. 360000"; } units "seconds"; default '3600'; description "Specifies the number of seconds that a NETCONF session may remain idle without issuing any RPC requests. A session will be dropped if it is idle for an interval longer than this number of seconds. If this parameter is 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. This mechanism is independent of keep-alives, as it regards activity occurring at the NETCONF protocol layer, whereas the keep-alive mechanism regards transport-level activity."; } } } grouping listen-container { description "This grouping is used only to help improve readability of the YANG module."; container listen { description "Configures listen behavior"; if-feature listen; leaf max-sessions { type uint16 { range "0 .. 1024"; } default '0'; description "Specifies the maximum number of concurrent sessions that can be active at one time. The value 0 indicates that no artificial session limit should be used."; } list endpoint { key name; description "List of endpoints to listen for NETCONF connections on."; leaf name { type string; description "An arbitrary name for the NETCONF listen endpoint."; } choice transport { mandatory true; description "Selects between SSH and TLS transports."; case ssh { if-feature ssh; container ssh { description "SSH-specific listening configuration for inbound connections."; uses address-and-port-grouping { refine port { default 830; } } uses host-keys-container; } } case tls { if-feature tls; container tls { description "TLS-specific listening configuration for inbound connections."; uses address-and-port-grouping { refine port { default 6513; } } uses certificates-container; } } } uses keep-alives-container { refine keep-alives/interval-secs { default 0; // disabled by default for listen connections } } } } } grouping call-home-container { description "This grouping is used only to help improve readability of the YANG module."; container call-home { if-feature call-home; description "Configures call-home behavior"; list application { key name; description "List of NETCONF clients the NETCONF server is to initiate call-home connections to."; leaf name { type string; description "An arbitrary name for the remote NETCONF client."; } choice transport { mandatory true; description "Selects between available transports."; case ssh { if-feature ssh; container ssh { description "Specifies SSH-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 7777; } } uses host-keys-container; } } case tls { if-feature tls; container tls { description "Specifies TLS-specific call-home transport configuration."; uses endpoints-container { refine endpoints/endpoint/port { default 8888; } } uses certificates-container; } } } container connection-type { description "Indicates the kind of connection to use."; choice connection-type { default persistent-connection; description "Selects between persistent and periodic connections."; case persistent-connection { container persistent { description "Maintain a persistent connection to the NETCONF client. If the connection goes down, immediately start trying to reconnect to it, 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."; uses keep-alives-container { refine keep-alives/interval-secs { default 15; // 15 seconds for call-home sessions } } } } case periodic-connection { container periodic { description "Periodically connect to NETCONF client, using the reconnection strategy, so the NETCONF client can deliver pending messages to the NETCONF server. For messages the NETCONF server wants to send to to the NETCONF client, the NETCONF server should proactively connect to the NETCONF client, if not already, to send the messages immediately."; leaf timeout-mins { type uint8; units minutes; default 5; description "The maximum amount of unconnected time the NETCONF server will wait until establishing a connection to the NETCONF client again. The NETCONF server MAY establish a connection before this time if it has data it needs to send to the NETCONF client. Note: this value differs from the reconnection strategy's interval-secs value."; } leaf linger-secs { type uint8; units seconds; default 30; description "The amount of time the NETCONF server should wait after last receiving data from or sending data to the NETCONF client's endpoint before closing its connection to it. This is an optimization to prevent unnecessary connections."; } } } } } container reconnect-strategy { description "The reconnection strategy guides how a NETCONF server reconnects to an NETCONF client, after losing a connection to it, even if due to a reboot. The NETCONF server starts with the specified endpoint and tries to connect to it count-max times, waiting interval-secs between each connection attempt, 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. NETCONF servers SHOULD support this flag across reboots."; } } 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. If no previous connection has ever been established, last-connected defaults to the first endpoint listed."; } leaf interval-secs { type uint8; units seconds; default 5; description "Specifies the time delay between connection attempts to the same endpoint. Note: this value differs from the periodic-connection's timeout-mins value."; } leaf count-max { type uint8; 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)."; } } } } } grouping ssh-container { description "This grouping is used only to help improve readability of the YANG module."; container ssh { description "Configures SSH properties not specific to the listen or call-home use-cases"; if-feature ssh; container x509 { if-feature ssh-x509-certs; uses trusted-certs-grouping; } } } grouping tls-container { description "This grouping is used only to help improve readability of the YANG module."; container tls { description "Configures TLS properties for authenticating clients."; if-feature tls; container client-auth { description "Container for TLS client authentication configuration."; uses trusted-certs-grouping; container cert-maps { uses x509c2n:cert-to-name; description "The cert-maps container is used by a 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."; } } } } grouping trusted-certs-grouping { description "This grouping is used by both the ssh and tls containers."; container trusted-ca-certs { description "A list of Certificate Authority (CA) certificates that a NETCONF server can use to authenticate NETCONF client certificates. A client's certificate is authenticated if there is a chain of trust to a configured trusted CA certificate. The client certificate MAY be accompanied with additional certificates forming a chain of trust. The client's certificate is authenticated if there is path-validation from any of the certificates it presents to a configured trust anchor."; leaf-list trusted-ca-cert { type binary; ordered-by system; nacm:default-deny-write; description "The binary certificate structure as specified by RFC 5246, Section 7.4.6, i.e.,: opaque ASN.1Cert<1..2^24>; "; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } } container trusted-client-certs { description "A list of client certificates that a NETCONF server can use to authenticate a NETCONF client's certificate. A client's certificate is authenticated if it is an exact match to a configured trusted client certificates."; leaf-list trusted-client-cert { type binary; ordered-by system; nacm:default-deny-write; description "The binary certificate structure, as specified by RFC 5246, Section 7.4.6, i.e.,: opaque ASN.1Cert<1..2^24>; "; reference "RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2"; } } } grouping host-keys-container { description "This grouping is used by both the listen and call-home containers"; container host-keys { description "Parent container for the list of host-keys."; leaf-list host-key { type string; min-elements 1; ordered-by user; description "A user-ordered list of host-keys the SSH server considers when composing the list of server host key algorithms it will send to the client in its SSH_MSG_KEXINIT message. The value of the string is the unique identifier for a host-key configured on the system. How valid values are discovered is outside the scope of this module, but they are envisioned to be the keys for a list of host-keys provided by another YANG module"; reference "RFC 4253: The SSH Transport Layer Protocol, Section 7"; } } } grouping certificates-container { description "This grouping is used by both the listen and call-home containers"; container certificates { description "Parent container for the list of certificates."; leaf-list certificate { type string; min-elements 1; description "An unordered list of certificates the TLS server can pick from when sending its Server Certificate message. The value of the string is the unique identifier for a certificate configured on the system. How valid values are discovered is outside the scope of this module, but they are envisioned to be the keys for a list of certificates provided by another YANG module"; reference "RFC 5246: The TLS Protocol, Section 7.4.2"; } } } grouping address-and-port-grouping { description "This grouping is usd by both the ssh and tls containers for listen configuration."; leaf address { type inet:ip-address; description "The IP address of the interface to listen on."; } leaf port { type inet:port-number; description "The local port number on this interface the NETCONF server listens on."; } } grouping endpoints-container { description "This grouping is used by both the ssh and tls containers for call-home configurations."; 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 NETCONF client. Defining more than one enables high-availability."; leaf name { type string; description "An arbitrary name for the endpoint to connect to."; } leaf address { type inet:host; mandatory true; description "The hostname or IP address or hostname of the endpoint. If a hostname is provided and DNS resolves to more than one IP address, the NETCONF server SHOULD try all of the ones it can based on how its networking stack is configured (e.g. v4, v6, dual-stack)."; } leaf port { type inet:port-number; description "The IP port for this endpoint. The NETCONF server will use the IANA-assigned well-known port if not specified."; } } } } grouping keep-alives-container { description "This grouping is use by both listen and call-home configurations."; container keep-alives { description "Configures the keep-alive policy, to proactively test the aliveness of the NETCONF client."; reference "RFC VVVV: NETCONF Server and RESTCONF Server Configuration Models, Section 4"; leaf interval-secs { type uint8; units seconds; description "Sets a timeout interval in seconds after which if no data has been received from the NETCONF client, a message will be sent to request a response from the NETCONF client. A value of '0' indicates that no keep-alive messages should be sent."; } leaf count-max { type uint8; default 3; description "Sets the number of keep-alive messages that may be sent without receiving any data from the NETCONF client before assuming the NETCONF client is no longer alive. If this threshold is reached, the transport-level connection will be disconnected, which will trigger the reconnection strategy). The interval timer is reset after each transmission, thus an unresponsive NETCONF client will be dropped after approximately (count-max * interval-secs) seconds."; } } } }