module vpp-classifier {
  yang-version 1;
  namespace "urn:opendaylight:params:xml:ns:yang:vpp:classifier";
  prefix "vpp-classifier";

  revision "2015-06-03" {
    description
      "Initial revision of model for VPP packet classifier.
      The model can be used ony to implement ACLs.
      Other classify table usages are not supported yet,
      see https://jira.fd.io/browse/VPP-203 for details.";
    reference
      "https://wiki.fd.io/view/VPP/Introduction_To_N-tuple_Classifiers";
  }

  import ietf-yang-types {
    prefix "yang";
  }

  typedef classify-table-ref {
    type leafref {
      path "/vpp-classifier:vpp-classifier/classify-table/name";
    }
    description
      "This type is used by data models that need to reference
       configured classify tables.";
  }

  typedef packet-handling-action {
    type enumeration {
      enum "deny" {
        // by VPP convention, first neighbour node (at index 0) is a drop node
        value 0;
      }
      enum "permit" {
        value -1; // indicates that the next node not set
      }
    }
  }

  typedef vpp-node-name {
    type string;
  }

  typedef vpp-node {
    type union {
      type packet-handling-action;
      type vpp-node-name;
    }
    description
      "Defines VPP node reference using packet handling action or relative node name
       (if definition in terms of packet handling action is not possible).";
  }

  typedef opaque-index {
    type union {
      type vpp-node;
      type uint32;
    }
    description
      "Defines opaque-index type - metadata that can be attached to session-hit packets.
       Vpp nodes can't be referenced by index, because node indexes might change after vpp restart.";
  }

  grouping classify-session-attributes {
    description
      "Defines classify session attributes that are mapped to classify_add_del_session
       and classify_session_details messages parameters.";

    leaf hit_next {
      type vpp-node;
      mandatory true;
      description
        "Vpp node to which packet will be send when it produces a match.";
    }
    leaf opaque_index {
      type opaque-index;
    }
    leaf advance {
      type int32;
      default 0;
      description
        "Nodes like ip4/6-classify use the parameter to \"consume\" networking layer.
        Example: tunnel decapsulation.";
    }
  }

  grouping classify-table-base-attributes {
    description
      "Defines classify table attributes that are mapped to classify_add_del_table message parameters.";

    leaf classifier-node {
      type vpp-node-name;
      description
        "Name of VPP node the table is defined for.";
    }
    leaf nbuckets {
      mandatory true;
      type uint32;
      description
        "Used by classifier hashing algorithm. It is not possible to resize the bucket array,
        therefore suggested value is approximate number of expected entries.";
    }
    leaf skip_n_vectors {
      type uint32;
      default 0;
      description
        "Number of 16 byte vectors to be skipped before applying mask.";
    }
    leaf next_table {
      type classify-table-ref;
      description
        "Reference to the next classify table. Required when multiple table chaining is used.";
    }
    leaf miss_next {
      mandatory true;
      type vpp-node;
      description
        "Vpp node to which packet will be send when it falis to produce a match";
    }
    leaf mask {
      type yang:hex-string;
      mandatory true;
      description
        "Defines match mask (multiple of 16 bytes)";
    }

    list classify-session {
      key "match";

      leaf match {
        type yang:hex-string;
        description
          "Defines actual value to be matched that is
           a byte vector, which length is multiple of 16 bytes";

        must "string-length(match) = string-length(../../mask)" {
          error-message
            "Match length is not equal to classify table mask length.";
          description
            "Match length must be equal to classify table mask length.";
        }
      }

      uses classify-session-attributes;
    }
  }

  grouping classify-table-config-attributes {
    description
      "Defines classify table config only attributes (present in classify_add_del_table message
       but not in classify_table_info_reply).";

    // FIXME move to classify-table-base-attributes
    // after https://jira.fd.io/browse/VPP-208 is fixed
    leaf memory_size {
      type uint32;
      mandatory true;
      description
        "Memory size for classify table and its entries.";
    }
  }

  grouping classify-table-operational-attributes {
    description
      "Defines classify table operational attributes (present in classify_table_info_reply message
       but not in classify_add_del_table).";

    leaf active_sessions {
      type uint32;
      config false;
      description
        "Number of sessions defined for the classify table.";
    }
  }

  container vpp-classifier {
    list classify-table {
      key "name";

      leaf name {
        type string;
        description
          "Hides classify table identifier managed by vpp.";
      }

      uses classify-table-base-attributes;
      uses classify-table-config-attributes;
    }
  }

  container vpp-classifier-state {
    config false;

    list classify-table {
      key "name";

      leaf name {
        type string;
        description
          "Hides classify table identifier managed by vpp.";
      }

      uses classify-table-base-attributes;
      uses classify-table-operational-attributes;
    }
  }

}