iconara / dennis

DNS proxy for OSX

Dennis

Dennis is a DNS proxy intended to work in Mac OS X. In principle, it allows the user to map any domain to any other domain. It is meant to be used in conjunction with the resolver system.

For example it can be used to map any lookup of a .ilovemyself domain to .com.

Installation

Dennis is most easily installed using

$ npm install -g dennis

Dennis needs a configuration file, which is read from ~/.dennis.json. Then run

$ dennis install

to get instructions for how dennis can be run in the background.

Configuration

An example Dennis configuration located in ~/.dennis.json looks like

{
  "port": 1553,
  "domains": {
    "ilovemyself": {
      "host": "8.8.8.8",
      "suffix": "com"
    }
  }
}

This configuration would make Dennis run on port 1553. For any query to a .ilovemyself domain, let's say example.ilovemyself, it would proxy the query to 8.8.8.8 but rewrite the name to example.net. Effectively Dennis would make .ilovemyself a mirror of .net.

The options for the configuration are:

• port (default: 1553) -- the port which Dennis will bind to
• domains (required)

Each key of domains is a domain to proxy, for which the following options are accepted:

• host (required) -- the host to proxy the request to
• port (default: 53) -- the port to use
• suffix (optional) -- the suffix to append to the domain, after removing the key itself. If no suffix is specified nothing will be appended. For example, given a request for example.com the proxy request will be example.
• proto (default: udp) -- the protocol to use, udp or tcp
• timeout (default: 1000) -- the number of milliseconds before considering the request timed out

Setting up resolver

For each entry to domains a corresponding mapping in the resolver system is required for Dennis to be used as a proxy. Let's say you want to use dennis for .ilovemyself. Then create /etc/resolver/ilovemyself with contents:

nameserver 127.0.0.1
port 1553