package charrua-client-mirage

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A DHCP client for MirageOS


Dune Dependency






charrua-client-mirage exposes an additional Dhcp_client_mirage for direct use with the MirageOS library operating system.



Published: 19 Jul 2019


Charrua DHCP - a DHCP client, server and wire frame encoder and decoder

charrua is an ISC-licensed DHCP library implementation in OCaml. It provides five packages:

  • charrua: a library that handles wire traffic parsing

  • charrua-server: a DHCP server implementation

  • charrua-client: a library for handling DHCP client state and messages

  • charrua-client-lwt: a DHCP client library with timeouts and network read/write

  • charrua-client-mirage: a MirageOS-compatible set of interfaces to charrua-client-lwt

  • charrua-unix: a Unix DHCP server implementation


The name charrua is a reference to the, now extinct, semi-nomadic people of southern South America.

Charrua consists of the single module Dhcp_wire responsible for parsing and constructing DHCP messages,

You can browse the API for charrua at

  • Dhcp_wire provides marshalling and unmarshalling utilities for DHCP, it is the base for Dhcp_server.

  • Logic/sequencing is agnostic of IO and platform, so it can run on Unix as a process, as a Mirage unikernel or anything else.

  • All DHCP options are supported at the time of this writing.

  • Code is purely applicative.

  • It's in OCaml, so it's pretty cool.


The module Dhcp_server supports a stripped down ISC dhcpd.conf, so you can probably just use your old dhcpd.conf. It also supports manual configuration building in OCaml.

dhcp is a MirageOS DHCP unikernel server based on charrua, included as a part of the MirageOS unikernel example and starting-point repository.


charrua-client is a DHCP client powered by charrua.

The base library exposes a simple state machine in Dhcp_client for use in acquiring a DHCP lease.

charrua-client-lwt extends charrua-client with a functor Dhcp_client_lwt, using the provided modules for timing and networking logic, for convenient use by a program which might wish to implement a full client.

charrua-client-mirage exposes an additional Dhcp_client_mirage for direct use with the MirageOS library operating system.

Charrua-unix Server

charrua-unix is an ISC-licensed Unix DHCP daemon based on charrua.

  • Supports a stripped down ISC dhcpd.conf. A configuration sample can be found here

  • Privilege dropping: the daemon doesn't run as root.

  • Almost purely-functional code.

  • Support for multiple interfaces/subnets.

Try charruad --help for options.

This project became one of the Mirage Pioneer projects.

Dependencies (11)

  1. lwt
  2. logs
  3. mirage-protocols-lwt >= "2.0.0" & < "5.0.0"
  4. mirage-net-lwt >= "2.0.0"
  5. mirage-time-lwt
  6. mirage-clock < "3.0.0"
  7. mirage-random >= "1.0.0" & < "2.0.0"
  8. ipaddr >= "3.0.0"
  9. charrua-client-lwt = version
  10. ocaml >= "4.04.2"
  11. dune >= "1.2"

Dev Dependencies


Used by (1)

  1. vpnkit >= "0.1.1"




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