nftables-json 0.3.0

# meta nfproto ipv4
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv4"
        }
    }
]

# meta nfproto ipv6
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv6"
        }
    }
]

# meta nfproto {ipv4, ipv6}
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": {
                "set": [
                    "ipv4",
                    "ipv6"
                ]
            }
        }
    }
]

# meta nfproto != {ipv4, ipv6}
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
            "op": "!=",
            "right": {
                "set": [
                    "ipv4",
                    "ipv6"
                ]
            }
        }
    }
]

# meta nfproto ipv6 tcp dport 22
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv6"
        }
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "dport",
                    "protocol": "tcp"
                }
            },
	    "op": "==",
            "right": 22
        }
    }
]

# meta nfproto ipv4 tcp dport 22
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv4"
        }
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "dport",
                    "protocol": "tcp"
                }
            },
	    "op": "==",
            "right": 22
        }
    }
]

# meta nfproto ipv4 ip saddr 1.2.3.4
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv4"
        }
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "saddr",
                    "protocol": "ip"
                }
            },
	    "op": "==",
            "right": "1.2.3.4"
        }
    }
]

# meta nfproto ipv6 meta l4proto tcp
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv6"
        }
    },
    {
        "match": {
            "left": {
                "meta": { "key": "l4proto" }
            },
	    "op": "==",
            "right": "tcp"
        }
    }
]

# meta nfproto ipv4 counter ip saddr 1.2.3.4
[
    {
        "match": {
            "left": {
                "meta": { "key": "nfproto" }
            },
	    "op": "==",
            "right": "ipv4"
        }
    },
    {
        "counter": null
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "saddr",
                    "protocol": "ip"
                }
            },
	    "op": "==",
            "right": "1.2.3.4"
        }
    }
]

# meta ipsec exists
[
    {
        "match": {
            "left": {
                "meta": {
                    "key": "ipsec"
                }
            },
            "op": "==",
            "right": true
        }
    }
]

# meta secpath missing
[
    {
        "match": {
            "left": {
                "meta": { "key": "secpath" }
            },
	    "op": "==",
            "right": false
        }
    }
]

# meta mark set ct mark >> 8
[
    {
        "mangle": {
            "key": {
                "meta": {
                    "key": "mark"
                }
            },
            "value": {
                ">>": [
                    {
                        "ct": {
                            "key": "mark"
                        }
                    },
                    8
                ]
            }
        }
    }
]

# meta protocol ip udp dport 67
[
    {
        "match": {
            "left": {
                "meta": {
                    "key": "protocol"
                }
            },
            "op": "==",
            "right": "ip"
        }
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "dport",
                    "protocol": "udp"
                }
            },
            "op": "==",
            "right": 67
        }
    }
]

# meta protocol ip6 udp dport 67
[
    {
        "match": {
            "left": {
                "meta": {
                    "key": "protocol"
                }
            },
            "op": "==",
            "right": "ip6"
        }
    },
    {
        "match": {
            "left": {
                "payload": {
                    "field": "dport",
                    "protocol": "udp"
                }
            },
            "op": "==",
            "right": 67
        }
    }
]