A YANG Data Model for BGP-LS Segment Routing Policy

<CODE BEGINS> file "ietf-bgp-ls-sr-policy@2026-10-28.yang"

module ietf-bgp-ls-sr-policy {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-bgp-ls-sr-policy";
  prefix bgp-ls-sr-policy;

  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 9911: Common YANG Data Types.";
  }
  import ietf-yang-types {
    prefix yang;
    reference
      "RFC 9911: Common YANG Data Types.";
  }
  import ietf-routing-types {
    prefix ietf-rt-t;
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area.";
  }
  import ietf-routing {
    prefix rt;
    reference
      "RFC 8349: A YANG Data Model for Routing Management
       (NMDA Version).";
  }
  import ietf-bgp {
    prefix bgp;
    reference
      "I-D.ietf-idr-bgp-model: BGP YANG Model for Service Provider
       Networks.";
  }
  import ietf-bgp-ls {
    prefix bgp-ls;
    reference
      "I-D.ietf-lsvr-bgp-ls-yang: A YANG Model for BGP-LS,
       BGP-LS-VPN, and BGP-LS-SPF.";
  }
  import ietf-bgp-lsdb {
    prefix bgp-lsdb;
    reference
      "I-D.ietf-lsvr-bgp-ls-yang: A YANG Model for BGP-LS,
       BGP-LS-VPN, and BGP-LS-SPF.";
  }
  import iana-bgp-ls-sr-policy-types {
    prefix iana-bgp-ls-srp-t;
    reference
      "RFC XXXX: A YANG Data Model for BGP-LS Segment Routing
       Policy.";
  }
  organization
    "IETF IDR Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/idr>
     WG List:  <mailto:idr@ietf.org>

     Authors:  Aravind Babu MahendraBabu
               <mailto:aramahen@cisco.com>
               Thanigaivel Manoharan
               <mailto:thanmano@cisco.com>";
  description
    "This module augments the operational Link-State Database in the
     BGP-LS YANG data model with a representation of the Segment
     Routing (SR) Policy Candidate Path NLRI and its associated
     BGP-LS attributes, as defined in RFC 9857.

     Copyright (c) 2026 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 XXXX; see the
     RFC itself for full legal notices.";

  revision 2026-10-28 {
    description
      "Initial revision.";
    reference
      "RFC 9857: Advertisement of Segment Routing Policies Using
       BGP - Link State.
       I-D.aravind-idr-bgp-ls-sr-policy-yang: A YANG Data Model for
       BGP-LS Segment Routing Policy.";
  }

  typedef protocol-origin {
    type union {
      type iana-bgp-ls-srp-t:protocol-origin;
      type uint8 {
        range "1..255";
      }
    }
    description
      "The component responsible for instantiating an SR Policy
       candidate path, from the IANA 'SR Policy Protocol-Origin'
       registry.  A code point that is not defined in the
       implemented revision of the IANA-maintained module is
       reported as a numeric value.";
    reference
      "RFC 9857, Sections 4 and 8.4.";
  }

  typedef metric-type {
    type union {
      type iana-bgp-ls-srp-t:metric-type;
      type uint8;
    }
    description
      "An SR Policy metric type from the IANA 'BGP-LS SR Policy
       Metric Types' registry.  A code point that is not defined
       in the implemented revision of the IANA-maintained module,
       including a User Defined code point, is reported as a
       numeric value.";
    reference
      "RFC 9857, Sections 5.6.6, 5.7.2, and 8.6.";
  }

  typedef segment-type {
    type union {
      type iana-bgp-ls-srp-t:segment-type;
      type uint8 {
        range "1..255";
      }
    }
    description
      "A Segment Type from the IANA 'BGP-LS SR Segment Descriptor
       Types' registry.  A code point that is not defined in the
       implemented revision of the IANA-maintained module is
       reported as a numeric value.";
    reference
      "RFC 9857, Sections 5.7.1 and 8.5.";
  }

  typedef descriptor-flags {
    type bits {
      bit endpoint-ipv6 {
        position 0;
        description
          "The endpoint is encoded as an IPv6 address.";
      }
      bit originator-ipv6 {
        position 1;
        description
          "The originator is encoded as an IPv6 address.";
      }
    }
    description
      "Flags in the SR Policy Candidate Path Descriptor TLV.";
    reference
      "RFC 9857, Section 4.";
  }

  typedef binding-sid-flags {
    type bits {
      bit srv6-dataplane {
        position 0;
        description
          "The Binding SID values are SRv6 SIDs instead of SR-MPLS
           labels.  This encoding is deprecated by RFC 9857.";
      }
      bit allocated {
        position 1;
        description
          "The Binding SID value is allocated.";
      }
      bit specified-unavailable {
        position 2;
        description
          "The specified Binding SID is unavailable.";
      }
      bit srlb {
        position 3;
        description
          "The Binding SID is from the headend SRLB.";
      }
      bit fallback {
        position 4;
        description
          "The value was dynamically allocated due to fallback.";
      }
    }
    description
      "Flags in the SR Binding SID TLV.  The SRLB flag applies only
       to an SR-MPLS Binding SID.";
    reference
      "RFC 9857, Section 5.1.";
  }

  typedef srv6-binding-sid-flags {
    type bits {
      bit allocated {
        position 0;
        description
          "The SRv6 Binding SID value is allocated.";
      }
      bit specified-unavailable {
        position 1;
        description
          "The specified SRv6 Binding SID is unavailable.";
      }
      bit fallback {
        position 2;
        description
          "The value was dynamically allocated due to fallback.";
      }
    }
    description
      "Flags in the SRv6 Binding SID TLV.";
    reference
      "RFC 9857, Section 5.2.";
  }

  typedef candidate-path-state-flags {
    type bits {
      bit administrative-shutdown {
        position 0;
        description
          "The candidate path is administratively shut down.";
      }
      bit active {
        position 1;
        description
          "The candidate path is active in the forwarding plane.";
      }
      bit backup {
        position 2;
        description
          "The candidate path is a backup path.";
      }
      bit evaluated {
        position 3;
        description
          "The candidate path has been evaluated for validity.";
      }
      bit valid {
        position 4;
        description
          "The candidate path has at least one valid SID list.";
      }
      bit on-demand-nexthop {
        position 5;
        description
          "The path was instantiated by an on-demand nexthop
           trigger.";
      }
      bit delegated {
        position 6;
        description
          "The path was delegated to a PCE or controller.";
      }
      bit provisioned {
        position 7;
        description
          "The path was provisioned by a PCE or controller.";
      }
      bit drop-upon-invalid {
        position 8;
        description
          "Drop-upon-invalid behavior is requested.";
      }
      bit transit-eligible {
        position 9;
        description
          "The path is eligible for use as a transit policy.";
      }
      bit dropping {
        position 10;
        description
          "The active path is dropping traffic due to
           drop-upon-invalid behavior.";
      }
    }
    description
      "Operational state flags for an SR Policy candidate path.";
    reference
      "RFC 9857, Section 5.3.";
  }

  typedef candidate-path-constraint-flags {
    type bits {
      bit srv6-dataplane {
        position 0;
        description
          "Use the SRv6 dataplane instead of SR-MPLS.";
      }
      bit protected {
        position 1;
        description
          "Prefer protected SIDs.";
      }
      bit unprotected {
        position 2;
        description
          "Prefer unprotected SIDs.";
      }
      bit specified-algorithm {
        position 3;
        description
          "Use SIDs belonging to the specified SR Algorithm.";
      }
      bit specified-topology {
        position 4;
        description
          "Use SIDs belonging to the specified topology.";
      }
      bit strict {
        position 5;
        description
          "Treat the protection preference as a strict constraint.";
      }
      bit fixed {
        position 6;
        description
          "The path is fixed after computation.";
      }
      bit hop-by-hop {
        position 7;
        description
          "Use only adjacency SIDs in hop-by-hop fashion.";
      }
    }
    description
      "Flags in the SR Candidate Path Constraints TLV.";
    reference
      "RFC 9857, Section 5.6.";
  }

  typedef disjoint-request-flags {
    type bits {
      bit srlg {
        position 0;
        description
          "SRLG disjointness is requested.";
      }
      bit node {
        position 1;
        description
          "Node disjointness is requested.";
      }
      bit link {
        position 2;
        description
          "Link disjointness is requested.";
      }
      bit fallback {
        position 3;
        description
          "Fallback to lower disjointness is permitted.";
      }
      bit best-path-fallback {
        position 4;
        description
          "Fallback to the default best path is permitted.";
      }
    }
    description
      "Requested SR disjointness constraints.";
    reference
      "RFC 9857, Section 5.6.4.";
  }

  typedef disjoint-status-flags {
    type bits {
      bit srlg {
        position 0;
        description
          "SRLG disjointness was achieved.";
      }
      bit node {
        position 1;
        description
          "Node disjointness was achieved.";
      }
      bit link {
        position 2;
        description
          "Link disjointness was achieved.";
      }
      bit fallback {
        position 3;
        description
          "Computation fell back to lower disjointness.";
      }
      bit best-path-fallback {
        position 4;
        description
          "Computation fell back to the default best path.";
      }
      bit invalid {
        position 5;
        description
          "The constraint could not be met and the path is invalid.";
      }
    }
    description
      "Achieved SR disjointness status.";
    reference
      "RFC 9857, Section 5.6.4.";
  }

  typedef bidirectional-flags {
    type bits {
      bit reverse {
        position 0;
        description
          "This candidate path is the reverse path.";
      }
      bit co-routed {
        position 1;
        description
          "The bidirectional path is co-routed.";
      }
    }
    description
      "Flags for an SR bidirectional group constraint.";
    reference
      "RFC 9857, Section 5.6.5.";
  }

  typedef metric-constraint-flags {
    type bits {
      bit optimization-metric {
        position 0;
        description
          "This is the optimization metric for the dynamic path.";
      }
      bit margin-present {
        position 1;
        description
          "A metric margin is present.";
      }
      bit absolute-margin {
        position 2;
        description
          "The margin is absolute rather than a percentage.";
      }
      bit bound-present {
        position 3;
        description
          "A metric bound is present.";
      }
    }
    description
      "Flags for an SR Metric Constraint sub-TLV.";
    reference
      "RFC 9857, Section 5.6.6.";
  }

  typedef segment-list-flags {
    type bits {
      bit srv6-dataplane {
        position 0;
        description
          "The SID list contains SRv6 SIDs.";
      }
      bit explicit {
        position 1;
        description
          "The SID list belongs to an explicit candidate path.";
      }
      bit computed {
        position 2;
        description
          "The SID list was computed.";
      }
      bit verified {
        position 3;
        description
          "The SID list passed verification or needed none.";
      }
      bit resolved {
        position 4;
        description
          "The first segment was resolved.";
      }
      bit computation-failed {
        position 5;
        description
          "Dynamic path computation failed.";
      }
      bit specified-algorithm {
        position 6;
        description
          "All SIDs belong to the specified algorithm.";
      }
      bit specified-topology {
        position 7;
        description
          "All SIDs belong to the specified topology.";
      }
      bit fault-monitor-removed {
        position 8;
        description
          "Fault monitoring removed the SID list from forwarding.";
      }
    }
    description
      "Flags in the SR Segment List TLV.";
    reference
      "RFC 9857, Section 5.7.";
  }

  typedef segment-flags {
    type bits {
      bit sid-present {
        position 0;
        description
          "The SID field is present.";
      }
      bit explicitly-provisioned {
        position 1;
        description
          "The SID was explicitly provisioned.";
      }
      bit verified {
        position 2;
        description
          "The SID passed verification or needed none.";
      }
      bit resolved {
        position 3;
        description
          "The SID was resolved or needed no resolution.";
      }
      bit algorithm-valid {
        position 4;
        description
          "The algorithm in the descriptor is valid.";
      }
    }
    description
      "Flags in an SR Segment sub-TLV.";
    reference
      "RFC 9857, Section 5.7.1.";
  }

  typedef segment-list-metric-flags {
    type bits {
      bit margin-present {
        position 0;
        description
          "A metric margin is present.";
      }
      bit absolute-margin {
        position 1;
        description
          "The margin is absolute rather than a percentage.";
      }
      bit bound-present {
        position 2;
        description
          "A metric bound is present.";
      }
      bit value-present {
        position 3;
        description
          "A computed metric value is present.";
      }
    }
    description
      "Flags in an SR Segment List Metric sub-TLV.";
    reference
      "RFC 9857, Section 5.7.2.";
  }

  grouping sr-policy-node-descriptors {
    description
      "Decoded fields of the Local Node Descriptors TLV identifying
       the SR Policy headend.";
    reference
      "RFC 9857, Section 3.";

    leaf as {
      type inet:as-number;
      description
        "Autonomous System Number in Node Descriptor TLV 512.  A
         value of zero indicates that the descriptor was absent.";
    }
    leaf bgp-router-id {
      type yang:dotted-quad;
      description
        "BGP Identifier in Node Descriptor TLV 516.  The value
         0.0.0.0 indicates that the descriptor was absent.";
    }
    leaf member-as {
      type inet:as-number;
      description
        "BGP Confederation Member ASN in Node Descriptor TLV 517.  A
         value of zero indicates that the descriptor was absent.";
    }

    leaf ipv4-router-id {
      type inet:ipv4-address;
      description
        "IPv4 Router-ID of the headend from TLV 1028.  The
         unspecified address is used when only an IPv6 Router-ID is
         present.";
    }
    leaf ipv6-router-id {
      type inet:ipv6-address;
      description
        "IPv6 Router-ID of the headend from TLV 1029.  The
         unspecified address is used when only an IPv4 Router-ID is
         present.";
    }
  }

  grouping sr-policy-candidate-path-descriptor {
    description
      "Decoded fields of the mandatory SR Policy Candidate Path
       Descriptor TLV.";
    reference
      "RFC 9857, Section 4.";

    leaf protocol-origin {
      type protocol-origin;
      mandatory true;
      description
        "Protocol or component that instantiated the path.";
    }
    leaf descriptor-flags {
      type descriptor-flags;
      mandatory true;
      description
        "Address-family flags from the descriptor TLV.";
    }
    leaf endpoint {
      type inet:ip-address;
      mandatory true;
      description
        "SR Policy endpoint.";
    }
    leaf color {
      type uint32;
      mandatory true;
      description
        "SR Policy color.";
    }
    leaf originator-as {
      type inet:as-number;
      mandatory true;
      description
        "ASN of the candidate-path originator.";
    }
    leaf originator-address {
      type inet:ip-address;
      mandatory true;
      description
        "Address of the candidate-path originator.";
    }
    leaf discriminator {
      type uint32;
      mandatory true;
      description
        "Candidate-path discriminator.";
    }
  }

  grouping group-identifier {
    description
      "Group identifier carried in the SR Disjoint Group and SR
       Bidirectional Group Constraint sub-TLVs.";
    reference
      "RFC 9857, Sections 5.6.4 and 5.6.5.";

    choice group-identifier {
      mandatory true;
      description
        "The identifier is encoded either as a 4-octet value or as
         an entire PCEP ASSOCIATION Object.";
      case group-id {
        leaf group-id {
          type uint32;
          description
            "4-octet group identifier.";
        }
      }
      case pcep-association-object {
        leaf pcep-association-object {
          type binary;
          description
            "Entire PCEP ASSOCIATION Object, including its optional
             TLVs, as received.  The object is not parsed by BGP
             speakers.";
          reference
            "RFC 8697: Path Computation Element Communication
             Protocol (PCEP) Extensions for Establishing
             Relationships between Sets of Label Switched Paths
             (LSPs), Section 6.1.";
        }
      }
    }
  }

  grouping candidate-path-constraints {
    description
      "Constraints associated with an SR Policy candidate path.";

    container constraints {
      presence "An SR Candidate Path Constraints TLV was received.";
      description
        "Constraints and optimization objectives for the path.";
      reference
        "RFC 9857, Section 5.6.";

      leaf flags {
        type candidate-path-constraint-flags;
        description
          "Constraint flags.";
      }
      leaf multi-topology-id {
        type uint16 {
          range "0..4095";
        }
        description
          "Preferred IGP multi-topology identifier.";
      }
      leaf algorithm {
        type uint8;
        description
          "Preferred SR Algorithm.";
      }

      container affinity {
        presence "An SR Affinity Constraint sub-TLV was received.";
        description
          "Extended Administrative Group affinity constraints.
           Each leaf-list entry represents one 32-bit word, in wire
           order.";
        reference
          "RFC 9857, Section 5.6.1.";

        leaf-list exclude-any {
          type uint32;
          ordered-by user;
          description
            "Affinity words for the exclude-any constraint.";
        }
        leaf-list include-any {
          type uint32;
          ordered-by user;
          description
            "Affinity words for the include-any constraint.";
        }
        leaf-list include-all {
          type uint32;
          ordered-by user;
          description
            "Affinity words for the include-all constraint.";
        }
      }

      leaf-list excluded-srlg {
        type uint32;
        ordered-by user;
        description
          "Shared Risk Link Group values excluded from the path.";
        reference
          "RFC 9857, Section 5.6.2.";
      }
      leaf bandwidth {
        type ietf-rt-t:bandwidth-ieee-float32;
        units "bytes per second";
        description
          "Requested bandwidth.  The protocol encodes this value as
           an IEEE 754 single-precision floating-point number.";
        reference
          "RFC 9857, Section 5.6.3.";
      }

      container disjoint-group {
        presence
          "An SR Disjoint Group Constraint sub-TLV was received.";
        description
          "Requested and achieved path disjointness.";
        reference
          "RFC 9857, Section 5.6.4.";

        leaf request-flags {
          type disjoint-request-flags;
          description
            "Requested disjointness properties.";
        }
        leaf status-flags {
          type disjoint-status-flags;
          description
            "Achieved disjointness properties.";
        }
        uses group-identifier;
      }

      container bidirectional-group {
        presence
          "An SR Bidirectional Group Constraint sub-TLV was
           received.";
        description
          "Bidirectional path association.";
        reference
          "RFC 9857, Section 5.6.5.";

        leaf flags {
          type bidirectional-flags;
          description
            "Bidirectional group flags.";
        }
        uses group-identifier;
      }

      list metric {
        key "type";
        description
          "Metric constraints associated with the candidate path.";
        reference
          "RFC 9857, Section 5.6.6.";

        leaf type {
          type metric-type;
          description
            "Metric type code point.";
        }
        leaf flags {
          type metric-constraint-flags;
          description
            "Metric constraint flags.";
        }
        leaf margin {
          type uint32;
          description
            "Absolute or percentage metric margin.";
        }
        leaf bound {
          type uint32;
          description
            "Worst metric value allowed for a valid path.";
        }
      }
    }
  }

  grouping segment-descriptor {
    description
      "Descriptor for one of the segment types defined by RFC 9857.";

    choice descriptor {
      description
        "Descriptor fields selected according to the segment type.";

      case type-a {
        container type-a {
          when "../type = 'type-a'";
          description
            "Type A: SR-MPLS label descriptor.";
          leaf algorithm {
            type uint8;
            mandatory true;
            description
              "IGP Algorithm used to select the SID.";
          }
        }
      }
      case type-b {
        container type-b {
          when "../type = 'type-b'";
          description
            "Type B: SRv6 SID descriptor.";
          leaf algorithm {
            type uint8;
            mandatory true;
            description
              "IGP Algorithm used to select the SID.";
          }
        }
      }
      case type-c {
        container type-c {
          when "../type = 'type-c'";
          description
            "Type C: IPv4 node address for an SR-MPLS Prefix SID.";
          leaf algorithm {
            type uint8;
            mandatory true;
            description
              "IGP Algorithm used to select the SID.";
          }
          leaf node-address {
            type inet:ipv4-address;
            mandatory true;
            description
              "IPv4 address associated with the node.";
          }
        }
      }
      case type-d {
        container type-d {
          when "../type = 'type-d'";
          description
            "Type D: IPv6 node address for an SR-MPLS Prefix SID.";
          leaf algorithm {
            type uint8;
            mandatory true;
            description
              "IGP Algorithm used to select the SID.";
          }
          leaf node-address {
            type inet:ipv6-address;
            mandatory true;
            description
              "IPv6 global address associated with the node.";
          }
        }
      }
      case type-e {
        container type-e {
          when "../type = 'type-e'";
          description
            "Type E: IPv4 node and local interface identifier.";
          leaf node-address {
            type inet:ipv4-address;
            mandatory true;
            description
              "IPv4 address associated with the node.";
          }
          leaf local-interface-id {
            type uint32;
            mandatory true;
            description
              "Local interface identifier.";
          }
        }
      }
      case type-f {
        container type-f {
          when "../type = 'type-f'";
          description
            "Type F: IPv4 local and remote interface addresses.";
          leaf local-interface-address {
            type inet:ipv4-address;
            mandatory true;
            description
              "Local interface address.";
          }
          leaf remote-interface-address {
            type inet:ipv4-address;
            mandatory true;
            description
              "Remote interface address; zero may indicate that the
               value is unused.";
          }
        }
      }
      case type-g {
        container type-g {
          when "../type = 'type-g'";
          description
            "Type G: IPv6 node addresses and interface identifiers
             for an SR-MPLS adjacency.";
          uses ipv6-node-and-interface-pair;
        }
      }
      case type-h {
        container type-h {
          when "../type = 'type-h'";
          description
            "Type H: IPv6 local and remote interface addresses for
             an SR-MPLS adjacency.";
          uses ipv6-interface-address-pair;
        }
      }
      case type-i {
        container type-i {
          when "../type = 'type-i'";
          description
            "Type I: IPv6 node address for an SRv6 End SID.";
          leaf algorithm {
            type uint8;
            mandatory true;
            description
              "IGP Algorithm used to select the SID.";
          }
          leaf node-address {
            type inet:ipv6-address;
            mandatory true;
            description
              "IPv6 global address associated with the node.";
          }
        }
      }
      case type-j {
        container type-j {
          when "../type = 'type-j'";
          description
            "Type J: IPv6 node addresses and interface identifiers
             for an SRv6 End.X SID.";
          uses ipv6-node-and-interface-pair;
        }
      }
      case type-k {
        container type-k {
          when "../type = 'type-k'";
          description
            "Type K: IPv6 local and remote interface addresses for
             an SRv6 End.X SID.";
          uses ipv6-interface-address-pair;
        }
      }
    }
  }

  grouping ipv6-node-and-interface-pair {
    description
      "IPv6 node addresses and interface identifiers for both ends
       of a link.";

    leaf local-node-address {
      type inet:ipv6-address;
      mandatory true;
      description
        "IPv6 global address of the local node.";
    }
    leaf local-interface-id {
      type uint32;
      mandatory true;
      description
        "Local node interface identifier.";
    }
    leaf remote-node-address {
      type inet:ipv6-address;
      mandatory true;
      description
        "IPv6 global address of the remote node; zero may indicate
         that the value is unused.";
    }
    leaf remote-interface-id {
      type uint32;
      mandatory true;
      description
        "Remote node interface identifier; zero may indicate that the
         value is unused.";
    }
  }

  grouping ipv6-interface-address-pair {
    description
      "IPv6 interface addresses for both ends of a link.";

    leaf local-interface-address {
      type inet:ipv6-address;
      mandatory true;
      description
        "IPv6 global address of the local interface.";
    }
    leaf remote-interface-address {
      type inet:ipv6-address;
      mandatory true;
      description
        "IPv6 global address of the remote interface.";
    }
  }

  grouping segment-lists {
    description
      "SID lists belonging to an SR Policy candidate path.";

    list segment-list {
      key "index";
      ordered-by user;
      description
        "A SID list in the order received.  The index is the
         zero-based position of the SID list within the candidate
         path.";
      reference
        "RFC 9857, Section 5.7.";

      leaf index {
        type uint32;
        description
          "Zero-based position of the SID list in the order
           received.";
      }
      leaf flags {
        type segment-list-flags;
        description
          "SID-list state and dataplane flags.";
      }
      leaf multi-topology-id {
        type uint16 {
          range "0..4095";
        }
        description
          "Multi-topology identifier used by the SID list.";
      }
      leaf algorithm {
        type uint8;
        description
          "SR Algorithm used by the SID list.";
      }
      leaf weight {
        type uint32;
        description
          "Weight used for load balancing across SID lists.";
      }
      leaf identifier {
        type uint32;
        description
          "Candidate-path-scoped SID-list identifier.  Zero means
           that no identifier is associated with the SID list.";
        reference
          "RFC 9857, Section 5.7.4.";
      }

      list segment {
        key "index";
        ordered-by user;
        description
          "An ordered segment in the SID list.";
        reference
          "RFC 9857, Section 5.7.1.";

        leaf index {
          type uint32;
          description
            "Zero-based position of the segment in the SID list.";
        }
        leaf type {
          type segment-type;
          mandatory true;
          description
            "Segment Type of the segment.";
        }
        leaf flags {
          type segment-flags;
          description
            "Segment state flags.";
        }
        choice sid {
          description
            "Resolved or explicitly provisioned SID value.  A SID
             value is present only when the 'sid-present' flag is
             set.";
          case mpls {
            leaf mpls-label {
              type ietf-rt-t:mpls-label-general-use;
              description
                "SR-MPLS label.";
            }
          }
          case srv6 {
            leaf srv6-sid {
              type inet:ipv6-address;
              description
                "SRv6 SID.";
            }
          }
        }

        uses segment-descriptor;
        uses bgp-lsdb:bgp-ls-topo-srv6-sid-attr;
        uses bgp-lsdb:bgp-ls-topo-unknown-attr;
      }

      list metric {
        key "type";
        description
          "Computed metric values for this SID list.";
        reference
          "RFC 9857, Section 5.7.2.";

        leaf type {
          type metric-type;
          description
            "Metric type code point.";
        }
        leaf flags {
          type segment-list-metric-flags;
          description
            "Metric presence and interpretation flags.";
        }
        leaf margin {
          type uint32;
          description
            "Absolute or percentage metric margin.";
        }
        leaf bound {
          type uint32;
          description
            "Worst metric value allowed for a valid path.";
        }
        leaf value {
          type uint32;
          description
            "Computed metric value.";
        }
      }

      leaf bandwidth {
        type ietf-rt-t:bandwidth-ieee-float32;
        units "bytes per second";
        description
          "Allocated bandwidth.  The protocol encodes this value as
           an IEEE 754 single-precision floating-point number.";
        reference
          "RFC 9857, Section 5.7.3.";
      }
      uses bgp-lsdb:bgp-ls-topo-unknown-attr;
    }
  }

  grouping sr-policy-candidate-paths {
    description
      "Operational SR Policy candidate paths advertised in BGP-LS.";

    container sr-policy-candidate-paths {
      description
        "BGP-LS topology entries for SR Policy Candidate Path
         NLRIs.";

      list candidate-path {
        must "ipv4-router-id != '0.0.0.0' or "
           + "ipv6-router-id != '::'" {
          error-message
            "At least one headend IPv4 or IPv6 Router-ID must be "
          + "present.";
          description
            "RFC 9857 requires at least one auxiliary Router-ID for
             the SR Policy headend.";
        }
        key "as bgp-router-id member-as ipv4-router-id "
          + "ipv6-router-id protocol-origin descriptor-flags "
          + "endpoint color originator-as originator-address "
          + "discriminator";
        description
          "An SR Policy candidate-path NLRI and its BGP-LS
           attributes.  The list key is the decoded Local Node
           Descriptors TLV followed by the mandatory SR Policy
           Candidate Path Descriptor TLV.";
        reference
          "RFC 9857, Sections 3 through 5.";

        uses sr-policy-node-descriptors;
        uses sr-policy-candidate-path-descriptor;

        container attributes {
          description
            "Decoded BGP-LS Attribute TLVs associated with the SR
             Policy Candidate Path NLRI.";

          leaf policy-name {
            type string;
            description
              "Symbolic SR Policy name from TLV 1213.  RFC 9857
               recommends, but does not require, that the name be
               limited to 255 octets.";
            reference
              "RFC 9857, Section 5.4.";
          }
          leaf candidate-path-name {
            type string;
            description
              "Symbolic candidate-path name from TLV 1203.  RFC 9857
               recommends, but does not require, that the name be
               limited to 255 octets.";
            reference
              "RFC 9857, Section 5.5.";
          }

          container sr-binding-sid {
            presence "An SR Binding SID TLV was received.";
            description
              "Binding SID state reported in the SR Binding SID TLV
               (TLV 1201).  The 'srv6-dataplane' flag (D-flag)
               selects between the SR-MPLS and SRv6 encodings.  The
               SRv6 encoding of this TLV is deprecated by RFC 9857
               and is represented only for backward compatibility;
               SRv6 Binding SIDs are otherwise represented by the
               srv6-binding-sid list (TLV 1212).";
            reference
              "RFC 9857, Section 5.1.";

            leaf flags {
              type binding-sid-flags;
              description
                "Binding SID status flags.";
            }
            choice dataplane {
              description
                "Binding SID values according to the dataplane
                 indicated by the 'srv6-dataplane' flag.";
              case mpls {
                leaf binding-sid {
                  when "not(bit-is-set(../flags, 'srv6-dataplane'))";
                  type ietf-rt-t:mpls-label-general-use;
                  description
                    "Allocated or operational SR-MPLS Binding SID.";
                }
                leaf specified-binding-sid {
                  when "not(bit-is-set(../flags, 'srv6-dataplane'))";
                  type ietf-rt-t:mpls-label-general-use;
                  description
                    "Explicitly specified SR-MPLS Binding SID.";
                }
              }
              case srv6 {
                leaf srv6-binding-sid {
                  when "bit-is-set(../flags, 'srv6-dataplane')";
                  type inet:ipv6-address;
                  description
                    "Allocated or operational SRv6 Binding SID.";
                }
                leaf srv6-specified-binding-sid {
                  when "bit-is-set(../flags, 'srv6-dataplane')";
                  type inet:ipv6-address;
                  description
                    "Explicitly specified SRv6 Binding SID.";
                }
              }
            }
          }

          list srv6-binding-sid {
            key "index";
            ordered-by user;
            description
              "An SRv6 Binding SID associated with the candidate
               path, in the order in which the SRv6 Binding SID TLVs
               were received.";
            reference
              "RFC 9857, Section 5.2.";

            leaf index {
              type uint32;
              description
                "Zero-based position of the SRv6 Binding SID TLV in
                 the order received.";
            }
            leaf binding-sid {
              type inet:ipv6-address;
              description
                "Allocated or operational SRv6 Binding SID.";
            }
            leaf flags {
              type srv6-binding-sid-flags;
              description
                "SRv6 Binding SID status flags.";
            }
            leaf specified-binding-sid {
              type inet:ipv6-address;
              description
                "Explicitly specified SRv6 Binding SID.";
            }
            uses bgp-lsdb:bgp-ls-topo-srv6-sid-attr;
            uses bgp-lsdb:bgp-ls-topo-unknown-attr;
          }

          container state {
            presence "An SR Candidate Path State TLV was received.";
            description
              "Operational status at candidate-path level.";
            reference
              "RFC 9857, Section 5.3.";

            leaf priority {
              type uint8;
              mandatory true;
              description
                "Candidate-path priority.";
            }
            leaf flags {
              type candidate-path-state-flags;
              description
                "Candidate-path operational state flags.";
            }
            leaf preference {
              type uint32;
              mandatory true;
              description
                "Candidate-path preference.";
            }
          }

          uses candidate-path-constraints;
          uses segment-lists;
          uses bgp-lsdb:bgp-ls-topo-unknown-attr;
        }
      }
    }
  }

  augment "/rt:routing/rt:control-plane-protocols/"
        + "rt:control-plane-protocol/bgp:bgp/bgp:global/"
        + "bgp:afi-safis/bgp:afi-safi/bgp-ls:link-state/"
        + "bgp-ls:bgp-ls-topology/bgp-ls:instances/"
        + "bgp-ls:instance" {
    when "bgp-ls:protocol = 'sr'" {
      description
        "SR Policy candidate-path NLRIs use the Segment Routing
         Protocol-ID (9).";
    }
    description
      "Add SR Policy Candidate Path NLRI entries to the BGP-LS
       Link-State Database.  This augmentation targets BGP-LS and not
       the separate BGP-LS-SPF Link-State Database instantiation.";
    uses sr-policy-candidate-paths;
  }
}

<CODE ENDS>

<CODE BEGINS> file "iana-bgp-ls-sr-policy-types@2026-10-28.yang"

module iana-bgp-ls-sr-policy-types {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:iana-bgp-ls-sr-policy-types";
  prefix iana-bgp-ls-srp-t;

  organization
    "Internet Assigned Numbers Authority (IANA)";
  contact
    "Internet Assigned Numbers Authority

     ICANN
     12025 Waterfront Drive, Suite 300
     Los Angeles, CA 90094-2536
     United States of America

     Tel:    +1 310 301 5800
     <mailto:iana@iana.org>";
  description
    "This module contains type definitions for the code points of
     the IANA registries used by SR Policy information distributed
     in BGP - Link State (BGP-LS).

     Copyright (c) 2026 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).

     The initial version of this YANG module is part of RFC XXXX;
     see the RFC itself for full legal notices.

     All revisions of IANA-maintained modules can be found in the
     'YANG Parameters' registry group
     (https://www.iana.org/assignments/yang-parameters).";

  revision 2026-10-28 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A YANG Data Model for BGP-LS Segment Routing
       Policy.";
  }

  typedef protocol-origin {
    type enumeration {
      enum pcep {
        value 1;
        description
          "PCEP.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum bgp-sr-policy {
        value 2;
        description
          "BGP SR Policy.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum configuration {
        value 3;
        description
          "Configuration (CLI, YANG model via NETCONF, etc.).";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum pcep-via-pce {
        value 10;
        description
          "PCEP (in PCEP or when BGP-LS Producer is PCE).";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum bgp-sr-policy-via-pce {
        value 20;
        description
          "BGP SR Policy (in PCEP or when BGP-LS Producer is PCE).";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum configuration-via-pce {
        value 30;
        description
          "Configuration (CLI, YANG model via NETCONF, etc.  In
           PCEP or when BGP-LS Producer is PCE).";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
    }
    description
      "Code points of the IANA 'SR Policy Protocol-Origin'
       registry.";
    reference
      "RFC 9857: Advertisement of Segment Routing Policies Using
       BGP - Link State, Section 8.4.";
  }

  typedef segment-type {
    type enumeration {
      enum type-a {
        value 1;
        description
          "Type A Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-b {
        value 2;
        description
          "Type B Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-c {
        value 3;
        description
          "Type C Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-d {
        value 4;
        description
          "Type D Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-e {
        value 5;
        description
          "Type E Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-f {
        value 6;
        description
          "Type F Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-g {
        value 7;
        description
          "Type G Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-h {
        value 8;
        description
          "Type H Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-i {
        value 9;
        description
          "Type I Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-j {
        value 10;
        description
          "Type J Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum type-k {
        value 11;
        description
          "Type K Segment.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
    }
    description
      "Code points of the IANA 'BGP-LS SR Segment Descriptor
       Types' registry.";
    reference
      "RFC 9857: Advertisement of Segment Routing Policies Using
       BGP - Link State, Section 8.5.";
  }

  typedef metric-type {
    type enumeration {
      enum igp {
        value 0;
        description
          "IGP.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum min-unidirectional-delay {
        value 1;
        description
          "Min Unidirectional Delay.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum te {
        value 2;
        description
          "TE.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum hop-count {
        value 3;
        description
          "Hop Count.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum sid-list-length {
        value 4;
        description
          "SID List Length.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum bandwidth {
        value 5;
        description
          "Bandwidth.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum avg-unidirectional-delay {
        value 6;
        description
          "Avg Unidirectional Delay.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum unidirectional-delay-variation {
        value 7;
        description
          "Unidirectional Delay Variation.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
      enum loss {
        value 8;
        description
          "Loss.";
        reference
          "RFC 9857: Advertisement of Segment Routing Policies
           Using BGP - Link State.";
      }
    }
    description
      "Code points of the IANA 'BGP-LS SR Policy Metric Types'
       registry.  The User Defined range (128-255) is not
       enumerated.";
    reference
      "RFC 9857: Advertisement of Segment Routing Policies Using
       BGP - Link State, Section 8.6.";
  }
}

<CODE ENDS>