Prevent a DOS-attack / OS-crash by flooding /tmp by including a confirmation-dialogue

[Tobias Baldauf]

Right now, there is no limit as to the size of files an uploader can sent to woof -U's webserver.

Therefore, it is possible to crash the Host's OS by sending a really large file (e.g. > 2GB) because it will be temporarily stored in /tmp, which will fill up the partition on which it is being written. Once the partition containing /tmp is full, the OS will become unresponsive.

The easiest solution - without restricting Woof's usability in sending whatever kind of file - is to enforce a confirmation-dialogue on the Host-machine when certain boundaries are crossed: Say, if an uploader wants to send more than X megabytes of data, this needs to be manually confirmed by the host.

There a 2 problems to this:
a) How do we determine the correct file-size of the file that the uploader wants to transmit? If we use client-side technology (JS), this may easily be manipulated.
b) How do we display a confirmation-dialogue if one of Woof's main goals is to keep out of the way & not to rely on GTK-windows as a GUI?

This problem needs research. Input on how to fix it is always welcome!