Muenfs

Introduction

The muenfs Linux kernel module implements a virtual file system that facilitates user-space access to shared memory channels provided by the Muen Separation Kernel.

For each detected channel, a file of matching size and permission is shown in the file system. A user-space application can use stat(2) calls to get the permissions (rw or r/o) of the files and the size of the region. For accessing file contents read(2), write(2), and mmap(2) operations are supported.

Usage

$ modprobe muenfs
$ mkdir -p /muenfs
$ mount -t muenfs none /muenfs

Example Code

See the test/muenfs-test.c program for example code on how to map a channel file and access its contents. The test/muenfs-example.c program illustrates how to use poll(2) to wait for an incoming event.

Authentication

The current authentication model is that the files are created with uid and gid set to 0. Depending on the type of the region the files have permissions 0400 or 0600. No further capability checking is done by this module.