seL4webserver reference application

This project contains an seL4 webserver application. Its purpose is to be a reference for implementing applications on seL4. Currently there is only a single configuration that runs a webserver inside a Linux VM component to serve a static website.

Current status

Currently there are two configurations for serving a static website from a webserver running inside a Linux guest on an odroid-xu4 on a local network. This includes a configuration with a single VM instance that serves a static website. The second configuration involves multiple VM’s serving a static website. The multiple VM configuration has an additional VM that acts as an network access point for the other VMs. It would be possible to modify which static website is being served by modifying the static html files located in /run/site/ in the Linux guest’s file system.

Plans

The purpose of this project is to build up a set of reference artifacts and system configurations that leverage seL4’s isolation guarantees and different board support packages. Currently everything is run inside a single camkes component and therefore doesn’t isolate different components. The next steps are to increase the amount of platforms that this app targets and to pull functionality out into separate isolated components. We also want to have an idea of performance characteristics for this system. Longer term steps involve constructing more complicated systems that have a network access point but also have functions that need to be strongly isolated in a secure way.

Short-term

  • Native application not involving Linux-VM
  • Additional platforms
  • Performance analysis/optimisation

Long-term

  • More complex system design

Setup

This project is based on an Arm VMM running inside a camkes system and therefore requires all of the Camkes dependencies described in Host Dependencies.

Additional dependencies required to run a lighttpd webserver serving docs.sel4.systems in a Linux guest:

  • docsite dependencies: Dependencies required to build docs.sel4.systems.
  • libpcre3-dev:armel
  • zlib compression library, armel arch: Required for building lighttpd (debian package: zlib1g-dev:armel)
  • pcre regex library, armel arch: Required for building lighttpd (debian package: libpcre3-dev:armel)
  • arm user binary emulation via qemu: Required for building lighttpd (debian package: qemu-user

Build instructions

# After initialising a fresh directory

# Obtain sources via repo tool
repo init -u https://github.com/SEL4PROJ/sel4webserver-manifest.git
repo sync

Configure: Single VM Webserver

# Initalise project build directory
mkdir build
cd build
../init-build.sh
# -- Configuring done
# -- Generating done
# -- Build files have been written to: /tmp/tmp.xmwD2Fc3FW/buildweb

Configure: Multi-VM Webserver

# Initalise project build directory
mkdir build
cd build
../init-build.sh -DMULTI_VM_LAN=1
# -- Configuring done
# -- Generating done
# -- Build files have been written to: /tmp/tmp.xmwD2Fc3FW/buildweb

Build Webserver

# build
ninja
# [0/1] Re-running CMake...
# -- Configuring done
# -- Generating done
# -- Build files have been written to: /tmp/tmp.xmwD2Fc3FW/buildweb
# [59/385] Performing CAmkES generation for 15 files
# ...
# [385/385] Generating images/capdl-loader-image-arm-exynos5

# Resulting artifacts:
ls images
# capdl-loader-image-arm-exynos5

See the Odroid XU4 hardware page on the docsite for additional information about running an seL4 image on an Odroid XU4.

Running the generated seL4webserver image will result in a running webserver listening on port 3000.

udhcpc: started, v1.27.2
[   10.485099] random: mktemp: uninitialized urandom read (6 bytes read)
udhcpc: sending [   10.504865] r8152 6-1:1.0 eth0: carrier on
discover
udhcpc: sending select for 10.13.1.7
udhcpc: lease of 10.13.1.7 obtained, lease time 3600
deleting routers
[   11.548877] random: mktemp: uninitialized urandom read (6 bytes read)
adding dns 10.13.0.8
adding dns 10.13.0.9

Welcome to Buildroot
buildroot login:

You could then navigate to 10.13.1.7:3000 in a web browser on the same local network.

Contributing

Contributions are welcome in the form of feature requests, documentation requests, or documentation/code contributions. See /Contributing for our general contribution guidelinies.

Current code contributions we would be interested to receive:

  • Additional platforms
  • Additional VM modules
  • Performance analysis

File included from github repo edit