DD-WRT

I spent some time today dissecting DD-WRT, which is an open source operating system used on many routers and embedded devices (that use Wireless technologies, especially 802.x).

Looks like it uses BusyBox for most of the binaries. BusyBox appears to be a single binary that can run many of the GNU / POSIX unix/linux-descended binaries. It's supposed to be more compact. For example, options have been stripped away or replaced on many of the binaries in the name of compact simplified code (lower footprint).  It is open source, so one can download, inspect, compile, etc.

For ssh, it uses something called DropBear. Again, a compact ssh server.

The webserver, httpd, looks to be an in-house developed web server (meaning, written by developers of dd-wrt). Chillispot is the access point controller.  ttraff is used as the traffic counter. dnsmasq is used as the DHCP server on the box.

All in all, the box looked very tight - with 40M used of 256M,

In some ways interesting, in other ways, uninteresting - which is a good thing for embedded devices.