SimpleMod

A small extendable linux kernel module based on ioctl calls. Extending the module is as simple as adding a new ioctl constant, and handling it in the kernel module.

Installation

The simplelib library relies on the simple_mod kernel module. Both the library and the the kernel module can be build by running

make

The library can be used by linking it to the application, or as a single header (simplelib.h) which can be directly included.

Requirements

The library requires a recent Linux kernel (tested on 4.11, but should also work on 3.x kernels). The library does not rely on any other library. It uses only standard C functionality.

Example

The basic functionality (simplelib_init and simplelib_cleanup) is always required. After the initialization, all functions provided by the library can be used. The basic implementation also provides the ioctl template in form of simplelib_hello, which makes a ioctl call to the kernel module. The kernel module handles such calls in the device_ioctl function, similarly to how a simple kernel implementation might handle syscalls.

To add a new ioctl call:

• Add a new constant in simple-mod.h
• Handle the constant in a switch case inside function device_ioctl in simple-mod.c
• Add a library wrapper inside simple.c
• make the module and library again
• Install the kernel module with insmod