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jc.parsers.nftables

jc - JSON Convert nftables command output parser

Parses nft list ruleset, nft list tables, and nft list table <family> <name>, with or without -a.

Rules and set/map elements are kept as nft prints them, minus the # handle N comment. Inline rule counters are also copied into counter_packets and counter_bytes. Named counter, quota, flowtable, limit, secmark, synproxy, and ct blocks are skipped. nft -j and nft monitor output are not supported.

Usage (cli):

$ nft list ruleset | jc --nftables

or

$ jc nft list ruleset

Usage (module):

import jc
result = jc.parse('nftables', nft_command_output)

Schema:

[
  {
    "family":                   string,
    "name":                     string,
    "handle":                   integer,    # [0]
    "comment":                  string,     # [1]
    "flags": [
                                string
    ],
    "chains": [
      {
        "name":                 string,
        "handle":               integer,    # [0]
        "type":                 string,     # [2]
        "hook":                 string,     # [1]
        "devices": [
                                string
        ],
        "priority":             string,     # [1]
        "policy":               string,     # [1]
        "comment":              string,     # [1]
        "rules": [
          {
            "rule":             string,
            "handle":           integer,    # [0]
            "counter_packets":  integer,    # [1]
            "counter_bytes":    integer     # [1]
          }
        ]
      }
    ],
    "sets": [
      {
        "name":                 string,
        "handle":               integer,    # [0]
        "type":                 string,     # [3]
        "flags": [
                                string
        ],
        "timeout":              string,     # [1]
        "gc_interval":          string,     # [1]
        "size":                 integer,    # [1]
        "policy":               string,     # [1]
        "auto_merge":           boolean,
        "counter":              boolean,
        "comment":              string,     # [1]
        "elements": [
                                string
        ]
      }
    ],
    "maps": [
      {
        # same fields as sets, plus:
        "value_type":           string      # [3]
      }
    ]
  }
]

[0] null unless `-a` was used
[1] null if not set
[2] null for a regular chain
[3] the `typeof` expression when the set or map is declared with
    `typeof` instead of `type`

Examples:

$ nft -a list ruleset | jc --nftables -p
[
  {
    "family": "inet",
    "name": "filter",
    "handle": 1,
    "comment": null,
    "flags": [],
    "chains": [
      {
        "name": "input",
        "handle": 1,
        "type": "filter",
        "hook": "input",
        "devices": [],
        "priority": "filter",
        "policy": "drop",
        "comment": null,
        "rules": [
          {
            "rule": "tcp dport 8080 counter packets 12 bytes 720 accept",
            "handle": 8,
            "counter_packets": 12,
            "counter_bytes": 720
          }
        ]
      }
    ],
    "sets": [],
    "maps": []
  }
]

$ nft -a list ruleset | jc --nftables -p -r
[
  {
    "family": "inet",
    "name": "filter",
    "handle": "1",
    "comment": null,
    "flags": [],
    "chains": [
      {
        "name": "input",
        "handle": "1",
        "type": "filter",
        "hook": "input",
        "devices": [],
        "priority": "filter",
        "policy": "drop",
        "comment": null,
        "rules": [
          {
            "rule": "tcp dport 8080 counter packets 12 bytes 720 accept",
            "handle": "8",
            "counter_packets": "12",
            "counter_bytes": "720"
          }
        ]
      }
    ],
    "sets": [],
    "maps": []
  }
]

parse

def parse(data: str,
          raw: bool = False,
          quiet: bool = False) -> List[Dict[str, Any]]

Main text parsing function

Parameters:

data:        (string)  text data to parse
raw:         (boolean) unprocessed output if True
quiet:       (boolean) suppress warning messages if True

Returns:

List of Dictionaries. Raw or processed structured data.

Parser Information

Compatibility: linux

Source: jc/parsers/nftables.py

Version 1.0 by Tung Lam (53996158+tunglambk@users.noreply.github.com)