{
  "nftables": [
    {
      "metainfo": {
        "version": "VERSION",
        "release_name": "RELEASE_NAME",
        "json_schema_version": 1
      }
    },
    {
      "table": {
        "family": "ip",
        "name": "x",
        "handle": 0
      }
    },
    {
      "chain": {
        "family": "ip",
        "table": "x",
        "name": "z",
        "handle": 0,
        "type": "filter",
        "hook": "input",
        "prio": 0,
        "policy": "accept"
      }
    },
    {
      "set": {
        "family": "ip",
        "name": "y",
        "table": "x",
        "type": "ipv4_addr",
        "handle": 0,
        "size": 65535,
        "flags": [
          "timeout",
          "dynamic"
        ]
      }
    },
    {
      "rule": {
        "family": "ip",
        "table": "x",
        "chain": "z",
        "handle": 0,
        "expr": [
          {
            "set": {
              "op": "add",
              "elem": {
                "payload": {
                  "protocol": "ip",
                  "field": "saddr"
                }
              },
              "set": "@y"
            }
          }
        ]
      }
    },
    {
      "rule": {
        "family": "ip",
        "table": "x",
        "chain": "z",
        "handle": 0,
        "expr": [
          {
            "set": {
              "op": "update",
              "elem": {
                "elem": {
                  "val": {
                    "payload": {
                      "protocol": "ip",
                      "field": "saddr"
                    }
                  },
                  "timeout": 30
                }
              },
              "set": "@y"
            }
          }
        ]
      }
    },
    {
      "rule": {
        "family": "ip",
        "table": "x",
        "chain": "z",
        "handle": 0,
        "expr": [
          {
            "match": {
              "op": "==",
              "left": {
                "payload": {
                  "protocol": "ip",
                  "field": "saddr"
                }
              },
              "right": "@y"
            }
          }
        ]
      }
    }
  ]
}