module ietf-inet-types {
  namespace "urn:ietf:params:xml:ns:yang:ietf-inet-types";
  prefix inet;

  organization
    "IETF Network Modeling (NETMOD) Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/netmod/>
     WG List:  <mailto:netmod@ietf.org>

     Editor:   Jürgen Schönwälder
               <mailto:jschoenwaelder@constructor.university>";
  description
    "This module contains a collection of generally useful derived
     YANG data types for Internet addresses and related things.

     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.

     Copyright (c) 2025 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 Revised 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 9911;
     see the RFC itself for full legal notices.";

  revision 2025-12-22 {
    description
      "This revision adds the following new data types:
       - inet:ip-address-and-prefix
       - inet:ipv4-address-and-prefix
       - inet:ipv6-address-and-prefix
       - inet:protocol-number
       - inet:upper-layer-protocol-number
       - inet:host-name
       - inet:email-address
       - inet:ip-address-link-local
       - inet:ipv4-address-link-local
       - inet:ipv6-address-link-local
       The inet:host union was changed to use inet:host-name instead
       of inet:domain-name.  Several pattern statements have been
       improved.";
    reference
      "RFC 9911: Common YANG Data Types";
  }
  revision 2013-07-15 {
    description
      "This revision adds the following new data types:
       - inet:ip-address-no-zone
       - inet:ipv4-address-no-zone
       - inet:ipv6-address-no-zone";
    reference
      "RFC 6991: Common YANG Data Types";
  }
  revision 2010-09-24 {
    description
      "Initial revision.";
    reference
      "RFC 6021: Common YANG Data Types";
  }

  /*** collection of types related to protocol fields ***/

  typedef ip-version {
    type enumeration {
      enum unknown {
        value 0;
        description
          "An unknown or unspecified version of the Internet
           Protocol.";
      }
      enum ipv4 {
        value 1;
        description
          "The IPv4 protocol as defined in RFC 791.";
      }
      enum ipv6 {
        value 2;
        description
          "The IPv6 protocol as defined in RFC 8200.";
      }
    }
    description
      "This value represents the version of the Internet Protocol.

       In the value set and its semantics, this type is equivalent
       to the InetVersion textual convention of the SMIv2.";
    reference
      "RFC  791: Internet Protocol
       RFC 8200: Internet Protocol, Version 6 (IPv6) Specification
       RFC 4001: Textual Conventions for Internet Network Addresses";
  }

  typedef dscp {
    type uint8 {
      range "0..63";
    }
    description
      "The dscp type represents a Differentiated Services Code Point
       that may be used for marking packets in a traffic stream.

       In the value set and its semantics, this type is equivalent
       to the Dscp textual convention of the SMIv2.";
    reference
      "RFC 3289: Management Information Base for the Differentiated
                 Services Architecture
       RFC 2474: Definition of the Differentiated Services Field
                 (DS Field) in the IPv4 and IPv6 Headers
       RFC 2780: IANA Allocation Guidelines For Values In
                 the Internet Protocol and Related Headers";
  }

  typedef ipv6-flow-label {
    type uint32 {
      range "0..1048575";
    }
    description
      "The ipv6-flow-label type represents the flow identifier or
       Flow Label in an IPv6 packet header that may be used to
       discriminate traffic flows.

       In the value set and its semantics, this type is equivalent
       to the IPv6FlowLabel textual convention of the SMIv2.";
    reference
      "RFC 3595: Textual Conventions for IPv6 Flow Label
       RFC 8200: Internet Protocol, Version 6 (IPv6) Specification";
  }

  typedef port-number {
    type uint16 {
      range "0..65535";
    }
    description
      "The port-number type represents a 16-bit port number of an
       Internet transport-layer protocol such as UDP, TCP, DCCP, or
       SCTP.

       Port numbers are assigned by IANA.  The current list of
       all assignments is available from <https://www.iana.org/>.

       Note that the port number value zero is reserved by IANA.  In
       situations where the value zero does not make sense, it can
       be excluded by subtyping the port-number type.

       In the value set and its semantics, this type is equivalent
       to the InetPortNumber textual convention of the SMIv2.";
    reference
      "RFC  768: User Datagram Protocol
       RFC 9293: Transmission Control Protocol (TCP)
       RFC 9260: Stream Control Transmission Protocol
       RFC 4340: Datagram Congestion Control Protocol (DCCP)
       RFC 4001: Textual Conventions for Internet Network Addresses";
  }

  typedef protocol-number {
    type uint8;
    description
      "The protocol-number type represents an 8-bit Internet
       Protocol number, carried in the 'protocol' field of the
       IPv4 header or in the 'next header' field of the IPv6
       header.

       Protocol numbers are assigned by IANA.  The current list of
       all assignments is available from <https://www.iana.org/>.";
    reference
      "RFC  791: Internet Protocol
       RFC 8200: Internet Protocol, Version 6 (IPv6) Specification";
  }

  typedef upper-layer-protocol-number {
    type protocol-number;
    description
      "The upper-layer-protocol-number represents the upper-layer
       protocol number carried in an IP packet.  For IPv6 packets
       with extension headers, this is the protocol number carried
       in the last 'next header' field of the chain of IPv6 extension
       headers.";
    reference
      "RFC  791: Internet Protocol
       RFC 8200: Internet Protocol, Version 6 (IPv6) Specification";
  }

  /*** collection of types related to autonomous systems ***/

  typedef as-number {
    type uint32;
    description
      "The as-number type represents autonomous system numbers
       that identify an Autonomous System (AS).  An AS is a set
       of routers under a single technical administration, using
       an interior gateway protocol and common metrics to route
       packets within the AS, and using an exterior gateway
       protocol to route packets to other ASes.  IANA maintains
       the autonomous system number space and has delegated large
       parts to the regional registries.

       Autonomous system numbers were originally limited to 16
       bits.  BGP extensions have enlarged the autonomous system
       number space to 32 bits.  This type therefore uses an uint32
       base type without a range restriction in order to support
       a larger autonomous system number space.

       In the value set and its semantics, this type is equivalent
       to the InetAutonomousSystemNumber textual convention of
       the SMIv2.";
    reference
      "RFC 1930: Guidelines for creation, selection, and registration
                 of an Autonomous System (AS)
       RFC 4271: A Border Gateway Protocol 4 (BGP-4)
       RFC 4001: Textual Conventions for Internet Network Addresses
       RFC 6793: BGP Support for Four-Octet Autonomous System (AS)
                 Number Space";
  }

  /*** collection of types related to IP addresses and hostnames ***/

  typedef ip-address {
    type union {
      type ipv4-address;
      type ipv6-address;
    }
    description
      "The ip-address type represents an IP address and is IP
       version neutral.  The format of the textual representation
       implies the IP version.  This type supports scoped addresses
       by allowing zone identifiers in the address format.";
    reference
      "RFC 4007: IPv6 Scoped Address Architecture";
  }

  typedef ipv4-address {
    type string {
      pattern
        '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
      + '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
      + '(%.+)?';
    }
    description
      "The ipv4-address type represents an IPv4 address in
       dotted-quad notation.  The IPv4 address may include a zone
       index, separated by a % sign.  If a system uses zone names
       that are not represented in UTF-8, then an implementation
       needs to use some mechanism to transform the local name
       into UTF-8.  The definition of such a mechanism is outside
       the scope of this document.

       The zone index is used to disambiguate identical address
       values.  For link-local addresses, the zone index will
       typically be the interface index number or the name of an
       interface.  If the zone index is not present, the default
       zone of the device will be used.

       The canonical format for the zone index is the numerical
       format";
  }

  typedef ipv6-address {
    type string {
      pattern '((:|[0-9a-fA-F]{0,4}):)([0-9a-fA-F]{0,4}:){0,5}'
            + '((([0-9a-fA-F]{0,4}:)?(:|[0-9a-fA-F]{0,4}))|'
            + '(((25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}'
            + '(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])))'
            + '(%[A-Za-z0-9][A-Za-z0-9\-\._~/]*)?';
      pattern '(([^:]+:){6}(([^:]+:[^:]+)|(.*\..*)))|'
            + '((([^:]+:)*[^:]+)?::(([^:]+:)*[^:]+)?)'
            + '(%.+)?';
    }
    description
      "The ipv6-address type represents an IPv6 address in full,
       mixed, shortened, and shortened-mixed notation.  The IPv6
       address may include a zone index, separated by a % sign.
       If a system uses zone names that are not represented in
       UTF-8, then an implementation needs to use some mechanism
       to transform the local name into UTF-8.  The definition of
       such a mechanism is outside the scope of this document.

       The zone index is used to disambiguate identical address
       values.  For link-local addresses, the zone index will
       typically be the interface index number or the name of an
       interface.  If the zone index is not present, the default
       zone of the device will be used.

       The canonical format of IPv6 addresses uses the textual
       representation defined in Section 4 of RFC 5952.  The
       canonical format for the zone index is the numerical
       format as described in Section 11.2 of RFC 4007.";
    reference
      "RFC 4291: IP Version 6 Addressing Architecture
       RFC 4007: IPv6 Scoped Address Architecture
       RFC 5952: A Recommendation for IPv6 Address Text
                 Representation";
  }

  typedef ip-address-no-zone {
    type union {
      type ipv4-address-no-zone;
      type ipv6-address-no-zone;
    }
    description
      "The ip-address-no-zone type represents an IP address and is
       IP version neutral.  The format of the textual representation
       implies the IP version.  This type does not support scoped
       addresses since it does not allow zone identifiers in the
       address format.";
    reference
      "RFC 4007: IPv6 Scoped Address Architecture";
  }

  typedef ipv4-address-no-zone {
    type ipv4-address {
      pattern '[0-9\.]*';
    }
    description
      "An IPv4 address without a zone index.  This type, derived
       from the type ipv4-address, may be used in situations where
       the zone is known from the context and no zone index is
       needed.";
  }

  typedef ipv6-address-no-zone {
    type ipv6-address {
      pattern '[0-9a-fA-F:\.]*';
    }
    description
      "An IPv6 address without a zone index.  This type, derived
       from the type ipv6-address, may be used in situations where
       the zone is known from the context and no zone index is
       needed.";
    reference
      "RFC 4291: IP Version 6 Addressing Architecture
       RFC 4007: IPv6 Scoped Address Architecture
       RFC 5952: A Recommendation for IPv6 Address Text
                 Representation";
  }

  typedef ip-address-link-local {
    type union {
      type ipv4-address-link-local;
      type ipv6-address-link-local;
    }
    description
      "The ip-address-link-local type represents a link-local IP
       address and is IP version neutral.  The format of the textual
       representation implies the IP version.";
  }

  typedef ipv4-address-link-local {
    type ipv4-address {
      pattern '169\.254\..*';
    }
    description
      "The ipv4-address-link-local type represents a link-local IPv4
       address in the prefix 169.254.0.0/16 as defined in Section 2.1
       of RFC 3927.";
    reference
      "RFC 3927: Dynamic Configuration of IPv4 Link-Local Addresses";
  }

  typedef ipv6-address-link-local {
    type ipv6-address {
      pattern '[fF][eE][89aAbB][0-9a-fA-F]:.*';
    }
    description
      "The ipv6-address-link-local type represents a link-local IPv6
       address in the prefix fe80::/10 as defined in Section 2.4 of
       RFC 4291.";
    reference
      "RFC 4291: IP Version 6 Addressing Architecture";
  }

  typedef ip-prefix {
    type union {
      type ipv4-prefix;
      type ipv6-prefix;
    }
    description
      "The ip-prefix type represents an IP prefix and is IP
       version neutral.  The format of the textual representations
       implies the IP version.";
  }

  typedef ipv4-prefix {
    type string {
      pattern
        '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
      + '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
      + '/(([0-9])|([1-2][0-9])|(3[0-2]))';
    }
    description
      "The ipv4-prefix type represents an IPv4 prefix.
       The prefix length is given by the number following the
       slash character and must be less than or equal to 32.

       A prefix length value of n corresponds to an IP address
       mask that has n contiguous 1-bits from the most
       significant bit (MSB) and all other bits set to 0.

       The canonical format of an IPv4 prefix has all bits of
       the IPv4 address set to zero that are not part of the
       IPv4 prefix.

       The definition of ipv4-prefix does not require that bits
       that are not part of the prefix be set to zero.  However,
       implementations have to return values in canonical format,
       which requires non-prefix bits to be set to zero.  This means
       that 192.0.2.1/24 must be accepted as a valid value, but it
       will be converted into the canonical format 192.0.2.0/24.";
  }

  typedef ipv6-prefix {
    type string {
      pattern '((:|[0-9a-fA-F]{0,4}):)([0-9a-fA-F]{0,4}:){0,5}'
            + '((([0-9a-fA-F]{0,4}:)?(:|[0-9a-fA-F]{0,4}))|'
            + '(((25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}'
            + '(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])))'
            + '(/(([0-9])|([0-9]{2})|(1[0-1][0-9])|(12[0-8])))';
      pattern '(([^:]+:){6}(([^:]+:[^:]+)|(.*\..*)))|'
            + '((([^:]+:)*[^:]+)?::(([^:]+:)*[^:]+)?)'
            + '(/.+)';
    }
    description
      "The ipv6-prefix type represents an IPv6 prefix.
       The prefix length is given by the number following the
       slash character and must be less than or equal to 128.

       A prefix length value of n corresponds to an IP address
       mask that has n contiguous 1-bits from the most
       significant bit (MSB) and all other bits set to 0.

       The canonical format of an IPv6 prefix has all bits of
       the IPv6 address set to zero that are not part of the
       IPv6 prefix.  Furthermore, the IPv6 address is represented
       as defined in Section 4 of RFC 5952.

       The definition of ipv6-prefix does not require that bits
       that are not part of the prefix be set to zero.  However,
       implementations have to return values in canonical format,
       which requires non-prefix bits to be set to zero.  This means
       that 2001:db8::1/64 must be accepted as a valid value, but it
       will be converted into the canonical format 2001:db8::/64.";
    reference
      "RFC 5952: A Recommendation for IPv6 Address Text
                 Representation";
  }

  typedef ip-address-and-prefix {
    type union {
      type ipv4-address-and-prefix;
      type ipv6-address-and-prefix;
    }
    description
      "The ip-address-and-prefix type represents an IP address and
       prefix and is IP version neutral.  The format of the textual
       representations implies the IP version.";
  }

  typedef ipv4-address-and-prefix {
    type string {
      pattern
        '(([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}'
      + '([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
      + '/(([0-9])|([1-2][0-9])|(3[0-2]))';
    }
    description
      "The ipv4-address-and-prefix type represents an IPv4
       address and an associated IPv4 prefix.
       The prefix length is given by the number following the
       slash character and must be less than or equal to 32.

       A prefix length value of n corresponds to an IP address
       mask that has n contiguous 1-bits from the most
       significant bit (MSB) and all other bits set to 0.";
  }

  typedef ipv6-address-and-prefix {
    type string {
      pattern '((:|[0-9a-fA-F]{0,4}):)([0-9a-fA-F]{0,4}:){0,5}'
            + '((([0-9a-fA-F]{0,4}:)?(:|[0-9a-fA-F]{0,4}))|'
            + '(((25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}'
            + '(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])))'
            + '(/(([0-9])|([0-9]{2})|(1[0-1][0-9])|(12[0-8])))';
      pattern '(([^:]+:){6}(([^:]+:[^:]+)|(.*\..*)))|'
            + '((([^:]+:)*[^:]+)?::(([^:]+:)*[^:]+)?)'
            + '(/.+)';
    }
    description
      "The ipv6-address-and-prefix type represents an IPv6
       address and an associated IPv6 prefix.
       The prefix length is given by the number following the
       slash character and must be less than or equal to 128.

       A prefix length value of n corresponds to an IP address
       mask that has n contiguous 1-bits from the most
       significant bit (MSB) and all other bits set to 0.

       The canonical format requires that the IPv6 address is
       represented as defined in Section 4 of RFC 5952.";
    reference
      "RFC 5952: A Recommendation for IPv6 Address Text
                 Representation";
  }

  /*** collection of domain name and URI types ***/

  typedef domain-name {
    type string {
      length "1..253";
      pattern
        '((([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.)*'
      + '([a-zA-Z0-9_]([a-zA-Z0-9\-_]){0,61})?[a-zA-Z0-9]\.?)'
      + '|\.';
    }
    description
      "The domain-name type represents a DNS domain name.  The
       name SHOULD be fully qualified whenever possible.  This
       type does not support wildcards (see RFC 4592) or
       classless in-addr.arpa delegations (see RFC 2317).

       Internet domain names are only loosely specified.  Section
       3.5 of RFC 1034 recommends a syntax (modified in Section
       2.1 of RFC 1123).  The pattern above is intended to allow
       for current practice in domain name use and some possible
       future expansion.  Note that Internet host names have a
       stricter syntax (described in RFC 952) than the DNS
       recommendations in RFCs 1034 and 1123.  Schema nodes
       representing host names should use the host-name type
       instead of the domain-type.

       The encoding of DNS names in the DNS protocol is limited
       to 255 characters.  Since the encoding consists of labels
       prefixed by a length byte and there is a trailing NUL
       byte, only 253 characters can appear in the textual dotted
       notation.

       The description clause of schema nodes using the domain-name
       type MUST describe when and how these names are resolved to
       IP addresses.  Note that the resolution of a domain-name value
       may require to query multiple DNS records (e.g., A for IPv4
       and AAAA for IPv6).  The order of the resolution process and
       which DNS record takes precedence can either be defined
       explicitly or depend on the configuration of the
       resolver.

       Domain-name values use the ASCII encoding.  Their canonical
       format uses lowercase ASCII characters.  Internationalized
       domain names MUST be A-labels as per RFC 5890.";
    reference
      "RFC  952: DoD Internet Host Table Specification
       RFC 1034: Domain Names - Concepts and Facilities
       RFC 1123: Requirements for Internet Hosts -- Application
                 and Support
       RFC 2317: Classless IN-ADDR.ARPA delegation
       RFC 2782: A DNS RR for specifying the location of services
                 (DNS SRV)
       RFC 4592: The Role of Wildcards in the Domain Name System
       RFC 5890: Internationalized Domain Names in Applications
                 (IDNA): Definitions and Document Framework
       RFC 9499: DNS Terminology";
  }

  typedef host-name {
    type domain-name {
      length "2..max";
      pattern '[a-zA-Z0-9\-\.]+';
    }
    description
      "The host-name type represents fully qualified host names.
       Host names must be at least two characters long (see RFC 952),
       and they are restricted to labels consisting of letters,
       digits, and hyphens separated by dots (see RFCs 1123 and
       952).";
    reference
      "RFC  952: DoD Internet Host Table Specification
       RFC 1123: Requirements for Internet Hosts -- Application
                 and Support";
  }

  typedef host {
    type union {
      type ip-address;
      type host-name;
    }
    description
      "The host type represents either an IP address or a fully
       qualified host name.";
  }

  typedef uri {
    type string {
      pattern '[a-z][a-z0-9+.-]*:.*';
    }
    description
      "The uri type represents a Uniform Resource Identifier
       (URI) as defined by the rule 'URI' in RFC 3986.

       Objects using the uri type MUST be in ASCII encoding
       and MUST be normalized as described in Sections 6.2.1,
       6.2.2.1, and 6.2.2.2 of RFC 3986.  Characters that can be
       represented without using percent-encoding are represented
       as characters (without percent-encoding), and all
       case-insensitive characters are set to lowercase except
       for hexadecimal digits within a percent-encoded triplet,
       which are normalized to uppercase as described in
       Section 6.2.2.1 of RFC 3986.

       The purpose of this normalization is to help provide
       unique URIs.  Note that this normalization is not
       sufficient to provide uniqueness.  Two URIs that are
       textually distinct after this normalization may still be
       equivalent.

       Objects using the uri type may restrict the schemes that
       they permit.  For example, 'data:' and 'urn:' schemes
       might not be appropriate.

       A zero-length URI is not a valid URI.  This can be used to
       express 'URI absent' where required.

       In the value set and its semantics, this type is equivalent
       to the Uri SMIv2 textual convention defined in RFC 5017.";
    reference
      "RFC 3986: Uniform Resource Identifier (URI): Generic Syntax
       RFC 3305: Report from the Joint W3C/IETF URI Planning Interest
                 Group: Uniform Resource Identifiers (URIs), URLs,
                 and Uniform Resource Names (URNs): Clarifications
                 and Recommendations
       RFC 5017: MIB Textual Conventions for Uniform Resource
                 Identifiers (URIs)";
  }

  typedef email-address {
    type string {
      pattern '.+@.+';
    }
    description
      "The email-address type represents an internationalized
       email address.

       The email address format is defined by the addr-spec
       ABNF rule in Section 3.4.1 of RFC 5322.  This format has
       been extended by RFC 6532 to support internationalized
       email addresses.  Implementations MUST support the
       internationalization extensions of RFC 6532.  Support
       for the obsolete obs-local-part, obs-domain, and
       obs-qtext in RFC 5322 is not required.

       The domain part may use both A-labels and U-labels
       (see RFC 5890).  The canonical format of the domain part
       uses lowercase characters and U-labels (RFC 5890) where
       applicable.";
    reference
      "RFC 5322: Internet Message Format
       RFC 5890: Internationalized Domain Names in Applications
                 (IDNA): Definitions and Document Framework
       RFC 6532: Internationalized Email Headers";
  }
}