{
  "nftables": [
    {
      "metainfo": {
        "version": "VERSION",
        "release_name": "RELEASE_NAME",
        "json_schema_version": 1
      }
    },
    {
      "table": {
        "family": "inet",
        "name": "t",
        "handle": 0
      }
    },
    {
      "chain": {
        "family": "inet",
        "table": "t",
        "name": "c",
        "handle": 0
      }
    },
    {
      "set": {
        "family": "inet",
        "name": "s",
        "table": "t",
        "type": [
          "ipv4_addr",
          "inet_service"
        ],
        "handle": 0,
        "size": 65536,
        "flags": [
          "timeout",
          "dynamic"
        ],
        "elem": [
          {
            "concat": [
              "192.168.7.1",
              22
            ]
          }
        ]
      }
    },
    {
      "rule": {
        "family": "inet",
        "table": "t",
        "chain": "c",
        "handle": 0,
        "expr": [
          {
            "match": {
              "op": "==",
              "left": {
                "payload": {
                  "protocol": "tcp",
                  "field": "dport"
                }
              },
              "right": 21
            }
          },
          {
            "set": {
              "op": "add",
              "elem": {
                "elem": {
                  "val": {
                    "concat": [
                      {
                        "payload": {
                          "protocol": "ip",
                          "field": "saddr"
                        }
                      },
                      22
                    ]
                  },
                  "timeout": 60
                }
              },
              "set": "@s"
            }
          }
        ]
      }
    }
  ]
}