---
name: "dnsjit"
section: "1"
platform: "linux"
package: "dnsjit"
version: "1.5.0-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dnsjit"
---

# dnsjit(1)

DNS engine based around LuaJIT for capturing, parsing, replaying and statistics gathering

## NAME

dnsjit - DNS engine based around LuaJIT for capturing, parsing, replaying and statistics gathering

## SYNOPSIS

### Run a Lua script

**dnsjit** *file.lua* *...*

### Shebang-style

  \#!/usr/bin/env dnsjit\
   ...

## DESCRIPTION

**dnsjit** is a combination of parts taken from **dsc**, **dnscap**, **drool,** and put together around Lua to create a script-based engine for easy capturing, parsing and statistics gathering of DNS message while also providing facilities for replaying DNS traffic.

One of the core functionality that **dnsjit** brings is to tie together C and Lua modules through a receiver/receive interface. This allows creation of custom chains of functionality to meet various requirements. Another core functionality is the ability to parse and process DNS messages even if the messages are non-compliant with the DNS standards.

**NOTE** current implementation is *ALPHA* which means functionality are not set and may be changed or removed.

## MODULE CATEGORIES

The following Lua module categories exists:

- **dnsjit.core**

  Core modules for handling things like logging, DNS messages and receiver/receive functionality.

- **dnsjit.lib**

  Various Lua libraries or C library bindings.

- **dnsjit.input**

  Input modules used to read DNS messages in various ways.

- **dnsjit.filter**

  Filter modules to process or manipulate DNS messages.

- **dnsjit.output**

  Output modules used to display DNS message, export to various formats or replay them against other targets.

See each category's man-page for more information.

## LUA GLOBALS

The following Lua global variables are defined:

- **DNSJIT\_VERSION**

  A string with the full version.

- **DNSJIT\_MAJOR\_VERSION**

  An integer with the major version number.

- **DNSJIT\_MINOR\_VERSION**

  An integer with the minor version number.

- **DNSJIT\_PATCH\_VERSION**

  An integer with the patch version number.

- **DNSJIT\_BUGREPORT**

  A string with the email address to file bug reports to.

- **DNSJIT\_URL**

  A string with the URL to the repository issue tracker, preferred place to file bug reports.

## EXAMPLE

Following example display the DNS ID found in queries.

  local input = require("dnsjit.input.pcapthread").new()\
   local output = require("dnsjit.filter.lua").new()

  output:func(function(filter, object)\
       local packet = object:cast()\
       local dns = require("dnsjit.core.object.dns").new(packet)\
       dns:parse()\
       print(dns.id)\
   end)

  input:open\_offline("file.pcap")\
   input:only\_queries(true)\
   input:receiver(output)\
   input:run()

See more examples in the *examples* directory.

## SEE ALSO

[**dnsjit.core**(3)](/dnsjit.core/3.md), [**dnsjit.lib**(3)](/dnsjit.lib/3.md), [**dnsjit.input**(3)](/dnsjit.input/3.md), [**dnsjit.filter**(3)](/dnsjit.filter/3.md), [**dnsjit.output**(3)](/dnsjit.output/3.md)

## AUTHORS

Jerry Lundström, DNS-OARC

Maintained by DNS-OARC

*https://www.dns-oarc.net/*

## BUGS

For issues and feature requests please use:

*https://github.com/DNS-OARC/dnsjit/issues*

For question and help please use:

*admin@dns-oarc.net*