Show HN: Detect software running from JavaScript in a browser

The demo currently only looks for these services but in theory could detect anything that opens a listener on a fixed port number: MySQL, Redis, ElasticSearch, MongoDB, Dropbox, Steam, DAAP media players, and Tor (daemon, browser, or Brave Tor mode).<p>I&#x27;ve been trying to accumulate a list of some of the more popular services that can be discovered this way here: <a href="https:&#x2F;&#x2F;github.com&#x2F;wybiral&#x2F;localtoast&#x2F;blob&#x2F;master&#x2F;js&#x2F;index.js" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;wybiral&#x2F;localtoast&#x2F;blob&#x2F;master&#x2F;js&#x2F;index.j...</a><p>It works in Chrome, Firefox, and curiously enough even the Tor mode of Brave Browser. Safari doesn&#x27;t seem to allow these types of requests.

You could also check for the LAN IP with WebRTC and scan (at least that network as a &#x2F;24) for services. You&#x27;d probably want to do something like that in a worker. Besides that, obviously browsers should seek permission for web sites to access resources from loopback&#x2F;RFC1918&#x2F;RC4193 addresses. You will however usually not be able to get information from them (CORS) but might affect services (get a ROKU to open an app etc.) with GET&#x2F;POSTS to certain services or devices.

User configuration options would help, so that in the browser you can specifically configure what connections are permitted.