HTTPAsm

The world's crappiest webserver and TCP/IP stack written in MIPS assembly.

Features

100% MIPS assembly.
Runs on GXemul.
Serves a small static web page with GET method.
Server can be remotely shut down with POST method.
Works with Google Chrome.
Requires no network configuration. It assumes all IP addresses and TCP ports.
Responds to ping.
Contains a terribly hacky stateless TCP/IP implementation.
Difficult to read.

Build the project

Use Ubuntu 16.10 64b.
Install gcc-5-mips-linux-gnu.
Run ./build.sh.

Run the project

You will need GXemul with TAP network interface. A binary is provided for 64b Ubuntu 16.10 for your convenience.

Run sudo ./run.sh to run the program on using the prebuilt gxemul binary.
Configure the new network interface. This will most likely be called tap0. You can assign any IP address to this interface. I usually run sudo ifconfig tap0 192.168.81.1
Visit the page in your browser. You just have to pick an IP from the assigned subnet. If you used the command above, 192.168.81.2 will work. (or 192.168.81.3,4,5,6,...)

How does this work?

Well, you could read the code and try to understand it. I have to warn you though: it is extremely ugly. It also does not look like what you would expect from a MIPS assembly program.

A few notable things:

The stack is not used.
There are no variables.
The entire server is a single big loop.
No state is preserved between received Ethernet frames.
The TCP implementation is stateless, so the HTTP requests and responses have to fit in a single Ethernet frame.
You could crash the server by sending it invalid TCP/IP frames, but you probably have something better to do anyway.
This works mostly because network stacks and browsers are well written and forgiving. It is otherwise an awful example for TCP/IP and HTTP.

Why?