module sonic-loopback-interface {

    yang-version 1.1;

    namespace "http://github.com/sonic-net/sonic-loopback-interface";
    prefix lointf;

    import sonic-types {
        prefix stypes;
    }

    import sonic-extension {
        prefix ext;
    }

    import sonic-vrf {
        prefix vrf;
    }

    description
        "SONIC LOOPBACK INTERFACE";

    revision 2021-04-05 {
        description "Modify the type of vrf name";
    }

    revision 2020-02-05 {
        description "First Revision";
    }

    container sonic-loopback-interface {

        container LOOPBACK_INTERFACE {

            list LOOPBACK_INTERFACE_LIST {
                key "name";

                leaf name{
                    type string;
                }

                leaf vrf_name {
                    type leafref {
                        path "/vrf:sonic-vrf/vrf:VRF/vrf:VRF_LIST/vrf:name";
                    }
                }

                leaf nat_zone {
                    description "NAT Zone for the loopback interface";
                    type uint8 {
                        range "0..3" {
                            error-message "Invalid nat zone for the loopback interface.";
                            error-app-tag nat-zone-invalid;
                        }
                    }
                    default "0";
                }
            }
            /* end of LOOPBACK_INTERFACE_LIST */

            list LOOPBACK_INTERFACE_IPPREFIX_LIST {

                key "name ip-prefix";

                leaf name{
                    description "Loopback interface name";

                    type leafref {
                        path "../../LOOPBACK_INTERFACE_LIST/name";
                    }
                }

                leaf ip-prefix {
                    type union {
                        type stypes:sonic-ip4-prefix;
                        type stypes:sonic-ip6-prefix;
                    }
                }

                leaf scope {
                    type enumeration {
                        enum global;
                        enum local;
                    }
                }

                leaf family {

                    /* family leaf needed for backward compatibility
                       Both ip4 and ip6 address are string in IETF RFC 6021,
                       so must statement can check based on : or ., family
                       should be IPv4 or IPv6 according.
                     */

                    must "(contains(../ip-prefix, ':') and current()='IPv6') or
                        (contains(../ip-prefix, '.') and current()='IPv4')";
                    type stypes:ip-family;
                }
            }
        }
        /* end of LOOPBACK_INTERFACE_IPPREFIX_LIST */
    }
}