module openconfig-fw-high-availability {

    yang-version 1;

    namespace
      "http://openconfig.net/yang/oc-fw-ha";

    prefix oc-fw-ha;

    import openconfig-extensions {
      prefix oc-ext;
    }
    import openconfig-interfaces {
      prefix oc-if;
    }
    import openconfig-inet-types {
      prefix oc-inet;
    }
    import openconfig-fw-link-monitoring {
      prefix oc-fw-linkmon;
    }
    import openconfig-aaa-types {
      prefix oc-aaa-types;
    }
    import openconfig-types {
      prefix oc-types;
    }

    organization "OpenConfig working group";

    contact
      "OpenConfig working group
    www.openconfig.net";

    description
      "Model used to configure & monitor firewall High Availability(HA).
    The model is comprised primarily of the following sections -
    - Various global config parameters
    (such as ha-group-id, ha-mode etc.)
    - Control link configuration parameters
    (control link is used to exchange HA control msgs)
    - Data link configuration parameters
    (data link is used to exchange information for seamless failover)
    - HA timers

    This model also imports/uses the link-monitoring module, to
    determine  health of firewall cluster based on the status of the
    interfaces being  monitored. Please see that module description
    for additional details";

    revision "2021-06-16" {
      description
        "Remove trailing whitespace";
      reference
        "0.2.1";

    }

    revision "2021-03-21" {
      description
        "Adding HA_PEER_MISMATCHED_ITEM identity.";
      reference
        "0.2.0";

    }

    revision "2020-06-23" {
      description "Initial version";
      reference
        "0.1.0";

    }

    oc-ext:openconfig-version "0.2.1";

    identity HA_PEER_MISMATCHED_ITEM {
      description
        "Base type to specify the HA parameters that are not matching
      amongst HA peers.";
    }

    identity SOFTWARE_MISMATCH {
      base HA_PEER_MISMATCHED_ITEM;
      description
        "Software version is not matching between HA peers.";
    }

    identity RUNNING_CONFIG_MISMATCH {
      base HA_PEER_MISMATCHED_ITEM;
      description
        "Running configuration is not matching between HA peers.";
    }

    identity IPS_SIGNATURES_MISMATCH {
      base HA_PEER_MISMATCHED_ITEM;
      description
        "IPS/IDS signatures are not matching between HA peers.";
    }

    identity AVC_SIGNATURES_MISMATCH {
      base HA_PEER_MISMATCHED_ITEM;
      description
        "AVC signatures are not matching between HA peers.";
    }

    grouping control-link-common-config {
      description
        "HA Control link configuration parameters";
      leaf control-link-interface {
        type oc-if:base-interface-ref;
        description
          "Specify which interface will be used to exchange HA control
         messages between peers";
      }

      leaf control-link-port {
        type oc-inet:port-number;
        description
          "Specify which TCP/UDP port will be used to exchange control
        messages";
      }

      leaf control-link-ipv4 {
        type oc-inet:ipv4-prefix;
        description
          "Specify the ipv4 address used by the fw for the control link";
      }

      leaf control-link-gateway {
        type oc-inet:ipv4-address;
        description
          "If peer control ipv4 is in a different subnet, specify the
        gateway ipv4 here to provide reachability";
      }

      leaf control-link-ipv6 {
        type oc-inet:ipv6-prefix;
        description
          "Specify the ipv6 address used by the fw for the control link";
      }

      leaf control-link-ipv6-gateway {
        type oc-inet:ipv6-address;
        description
          "If peer control ipv6 is in a different subnet, specify the
        gateway ipv6 here to provide reachability";
      }

      leaf control-link-peer-ipv4 {
        type oc-inet:ipv4-prefix;
        description
          "Specify the peer ipv4 address, if control link is utilizing
        Layer 3";
      }

      leaf control-link-peer-ipv6 {
        type oc-inet:ipv6-prefix;
        description
          "Specify the peer ipv6 address, if control link is utilizing
        Layer 3";
      }
    }  // grouping control-link-common-config

    grouping data-link-common-config {
      description
        "HA data link configuration parameters";
      leaf data-link-interface {
        type oc-if:base-interface-ref;
        description
          "Specify which interface will be used to sync session tables,
        forwarding tables, ARP tables, IPSEC SAs and any other
        messages that MUST be exchanged to facilitate seamless traffic
         handling during a failover event";
      }

      leaf data-link-port {
        type oc-inet:port-number;
        description
          "Specify which TCP/UDP port will be used to exchange data link
         messages";
      }

      leaf data-link-ipv4 {
        type oc-inet:ipv4-prefix;
        description
          "If data link is layer 3, specify the local unit's ipv4
        address";
      }

      leaf data-link-gateway {
        type oc-inet:ipv4-address;
        description
          "If peer data ip is in a different subnet, specify the gateway
         ip here to provide reachability";
      }

      leaf data-link-ipv6 {
        type oc-inet:ipv6-prefix;
        description
          "If data link is layer 3, specify the local unit's ipv6
        address";
      }

      leaf data-link-ipv6-gateway {
        type oc-inet:ipv6-address;
        description
          "If peer data ipv6 is in a different subnet, specify the
        gateway ipv6 here to provide reachability";
      }

      leaf data-link-peer-ipv4 {
        type oc-inet:ipv4-prefix;
        description
          "If data link is layer 3, specify the peer's ipv4 address";
      }

      leaf data-link-peer-ipv6 {
        type oc-inet:ipv6-prefix;
        description
          "If data link is layer 3, specify the peer's ipv6 address";
      }
    }  // grouping data-link-common-config

    grouping ha-timers-config {
      description
        "Used to specify various HA timers";
      leaf preempt-hold-timer {
        type uint32;
        units "milliseconds";
        description
          "Length of time, from the last received Hello message,
        a firewall will wait before taking over the active role in a
        HA pair";
      }

      leaf hello-interval {
        type uint32;
        units "milliseconds";
        description
          "Interval between hello messages exchanged by the HA peers";
      }
    }  // grouping ha-timers-config

    grouping ha-parameters-config {
      description
        "All parameters needed to bootstrap a HA cluster";
      leaf ha-enabled {
        type boolean;
        default 'false';
        description
          "This must be set to 'true' to initiate firewall participation
        in a HA cluster. Once set to 'true', this boolean can be
        flipped to 'false' to DISABLE HA and put a unit in a
        'suspended' state while retaining all other HA settings &
        configuration parameters. At the same time the 'ha-state' leaf
        under 'ha-parameters-state' must then be updated to
        'SUSPENDED'";
      }

      leaf ha-mode {
        type enumeration {
          enum "ACTIVE_PASSIVE" {
            value 0;
            description
              "This value indicates the HA cluster is operating in
              active/passive mode. In this scenario there are only
              ever two firewalls in the cluster. The active firewall
              serves as the 'primary' handling the traffic & the
              passive firewall acts as a 'secondary' ready to take
              over if the 'active' unit fails";
          }
        }
        description "Configurable HA modes";
      }

      leaf ha-key {
        type string;
        description
          "HA key used to encrypt & authenticate HA messages betwen
          the peers. This is provided in clear-text by the client &
          expected to be hashed by the firewall in the configuration";
      }

      leaf ha-key-hashed {
        type oc-aaa-types:crypt-password-type;
        description
          "HA key,used to encrypt & authenticate HA messages between
          the peers, supplied as a hashed value using the notation
	        described in the definition of the crypt-password-type";
      }

      leaf ha-msg-encryption {
        type boolean;
        default 'false';
        description
          "When set to true all traffic between firewall units in a HA
        cluster are encrypted. If operator provided encryption key is
        supported, that value must be derived from the
        ha-key/ha-key-hashed leaf nodes. If that is not supported, the
        vendor is expected to derive it's own keying material";
      }

      leaf id {
        type uint8;
        description
          "The high availbility group id for a unit. This value MUST
        match across both units participating in a HA cluster";
      }

      leaf ha-device-id {
        type uint8;
        description
          "Specify the device-id to identify the firewall within a HA
        group. This value MUST be unique to the local-unit and MUST
        NOT clash with the peer within a ha-group";
      }

      leaf preempt {
        type boolean;
        default 'false';
        description
          "When set to true the firewall forces reelection of the active
         role after joining the cluster";
      }

      leaf priority {
        type uint8;
        description
          "Set priority value for the firewall. This value is used
        to participate in the election of the active unit in the HA
        cluster. Firewall with highest priority is elected as the
        ACTIVE unit";
      }

      uses ha-timers-config;

      uses oc-fw-linkmon:global-health-config;
    }  // grouping ha-parameters-config

    grouping ha-parameters-state {
      description
        "All parameters needed to monitor a HA cluster";
      leaf ha-state {
        type enumeration {
          enum "ACTIVE" {
            value 0;
            description
              "Firewall is 'active' and handling all traffic in a
              cluster";
          }
          enum "PASSIVE" {
            value 1;
            description
              "Firewall is 'passive' in a two-unit cluster ready to
              handle traffic if the 'active' unit fails";
          }
          enum "DEGRADED" {
            value 2;
            description
              "Firewall is in a 'degraded' state and unable to join
              the cluster due to config or operational failures";
          }
          enum "SUSPENDED" {
            value 3;
            description
              "This state represents a firewall which will not join
               the cluster due to 'ha-enable' set to, or left at it's
               default of, 'false'";
          }
        }
        description
          "Firewall's operational ha-state";
      }

      leaf ha-state-last-change {
        type oc-types:timeticks64;
        units "nanoseconds";
        description
          "Reports the time the firewall entered its current HA
        operational state. The value is the timestamp in nanoseconds
        relative to the Unix Epoch (Jan 1, 1970 00:00:00 UTC).";
      }

      leaf ha-config-sync {
        type boolean;
        description
          "Returns 'TRUE' if config sync is operational between HA
        peers. Returns 'FALSE' otherwise.";
      }

      leaf ha-session-sync {
        type boolean;
        description
          "Returns 'TRUE' if session sync is operational between HA
        peers. Returns 'FALSE' otherwise.";
      }

      leaf-list ha-mismatched-parameters {
        type identityref {
          base HA_PEER_MISMATCHED_ITEM;
        }
        description
          "List of HA parameters that are mismatched between peers. Use
        this list to highlight root cause of HA operational issues
        that an operator must fix";
      }

      uses oc-fw-linkmon:global-health-state;
    }  // grouping ha-parameters-state

    grouping control-link-backup {
      description
        "Structural grouping for backup HA control link";
      container backup {
        description
          "Data related to backup HA control link";
        container config {
          description
            "Configuration data related to backup HA control link";
          uses control-link-common-config;
        }  // container config

        container state {
          config false;
          description
            "Operational state data related to backup HA control link";
          uses control-link-common-config;
        }  // container state
      }  // container backup
    }  // grouping control-link-backup

    grouping control-link-top {
      description
        "Structural grouping for HA control link";
      container control-link {
        description
          "Top-level container for HA control link";
        container config {
          description
            "Configuration parameters related to primary HA control
          link";
          uses control-link-common-config;
        }  // container config

        container state {
          config false;
          description
            "Operational state data related to primary HA control link";
          uses control-link-common-config;
        }  // container state

        uses control-link-backup;
      }  // container control-link
    }  // grouping control-link-top

    grouping data-link-backup {
      description
        "Structural grouping for backup HA data link";
      container backup {
        description
          "Parameters related to backup HA data link";
        container config {
          description
            "Configuration parameters related to backup HA data link";
          uses data-link-common-config;
        }  // container config

        container state {
          config false;
          description
            "Operational state parameters related to backup HA data
          link";
          uses data-link-common-config;
        }  // container state
      }  // container backup
    }  // grouping data-link-backup

    grouping data-link-top {
      description
        "Structural grouping for HA data link";
      container data-link {
        description
          "Top-level container for HA data link";
        container config {
          description
            "Configuration parameters related to primary HA data link";
          uses data-link-common-config;
        }  // container config

        container state {
          config false;
          description
            "Operational state parameters related to primary HA data
          link";
          uses data-link-common-config;
        }  // container state

        uses data-link-backup;
      }  // container data-link
    }  // grouping data-link-top

    grouping ha-configuration-top {
      description
        "Top level grouping for HA configuration and operational state
         data";
      container ha-groups {
        description
          "Top level container for HA groups";
        list ha-group {
          key "id";
          description
            "HA group id used to create a logical HA group";
          leaf id {
            type leafref {
              path "../config/id";
            }
            description
              "References the group id key.";
          }

          container config {
            description
              "Config container for HA parameters";
            uses ha-parameters-config;
          }  // container config

          container state {
            config false;
            description
              "State container for HA parameters";
            uses ha-parameters-config;

            uses ha-parameters-state;
          }  // container state

          uses control-link-top;

          uses data-link-top;

          uses oc-fw-linkmon:interface-group-top;
        }  // list ha-group
      }  // container ha-groups
    }  // grouping ha-configuration-top

    uses ha-configuration-top;
  }  // module openconfig-fw-high-availability