ChimeraDesk

A simple, fast and flexible DIY Remote Desktop software

Glossary

• remote computer : the one you want to connect to
• local computer : the one you can physically type on
• remote/pubblic server : (for reverse ssh configuration) it can be a VPS or generally any public server under no NAT network

Requirements

• On the remote pc: ffmpeg libnotify-bin

Infrastructure

You can use this ChimeraDesk

• In centralized mode Local --> Public Server <-- Remote (TW-style) if you can't/don't want to open ports on your router, or
• In p2p mode Local --> Remote (RDP-style) if you can/want to open ports on your router.

Setup for centralized mode (optional)

If you need to connect between two NAT networks without opening ports on either side (like t.w. does)

1. On a public server you own, configure ssh gateway ports by adding GatewayPorts clientspecified to sshd_config
2. On the remote computer you want to connect to, enable ssh and optionally create a key to be used to connect without password:

systemctl enable --now ssh
ssh-keygen -t rsa -f ~/.ssh/reverse-key
ssh-copy-id -i ~/.ssh/reverse-key <user@server>

3. Now create a tunnel so you can forward all ssh requests (on port 8080 for example) to the ssh service running on your remote machine:

ssh -i ~/.ssh/reverse-key -Ng -R *:8080:localhost:22 user@server

USAGE

In the following section we will refer to IP as:

• Your public server IP if you are running in centralized mode
• Your remote computer IP if you can open port 22 on the remote computer NAT network (p2p mode). In such case -p 8080 must be omitted unless you decide to open port 8080 to 22 in your router (suggested).

1. Connect to the remote computer and forward local requests on ports 12345 and 12346 to localhost:

ssh -R 12344:127.0.0.1:12344 -R 12345:127.0.0.1:12345 -R 12346:127.0.0.1:12346 user@IP -p 8080
# This will also yield a shell you can use on step 3.

2. Launch ChimeraDesk-x86_64.AppImage on your local computer.
3. Launch ChimeraDesk-KVM-x86_64.AppImage on your remote computer

That's it!

You should now be able to see and control the remote screen.

Please note that the 'viewer' AppImage can be twice as heavy on the CPU compared to the natively built executable. Check the building instructions if you care about efficiency. It's simple enough and performs much better :)

Streaming desktop audio

Due to video + audio muxing latency issues, desktop audio needs to be carried over by a separate stream. At this point in time I've not integrated this feature in the ChimeraDesk App yet, but the KVM already streams the audio on port 12344 and you can listen to it with ffplay.

BEFORE running the KVM component on the remote side, start listening on your local (controller) machine with:

ffplay -f s16le -ar 44100 -ac 2 -probesize 32 -analyzeduration 0 -sync ext "tcp://0.0.0.0:12344?listen"

There you go!

Configuration

Configuration is kept minimal and you get (arguably) reasonable default settings out of the box.

Network configuration

Everything is binding on localhost to let the user tunnel the traffic the way he/she wants. In order to maximize flexibility and keep the code simple, the application should not care about network configuration and encryption. Plese note that encryption is not provided so SSH (or equivalent encrypted tunneling such as VPN) is highly recommended.

FFMPEG streaming configuration

On first launch, the application writes a default ffmpeg command line under ~/.config/hprdpvideo.sh:

echo $BASHPID > /tmp/ffmpeg.pid; ffmpeg ... some other stuff ....

You are free to change anything at your will, but be sure to keep the echo $BASHPID > /tmp/ffmpeg.pid; prefix as it's needed for terminating ffmpeg via UI dialog.

Please note that this file is considered user configuration and therefore never updated again by the program. If you expirience issues with the video configuration, try removing it before restarting the kvm component.

Building Instruction

Example building on Ubuntu 18.04

Build the App on GNU/Linux

On Ubuntu 18.04 You need the latest libmpv-dev so add this PPA first: sudo add-apt-repository ppa:mc3man/bionic-media

1. Install build dependencies: sudo apt install git gcc libmpv-dev libsdl2-dev libsdl2-ttf-dev
2. Clone this repo: git clone https://github.com/morrolinux/ChimeraDesk.git
3. Move to the App directory: ChimeraDesk/App/sdl/
4. And build it with: gcc -o main main.c $(pkg-config --libs --cflags mpv sdl2 SDL2_ttf) -std=c99

If everything went fine (no errors) you can run ./main TCP (or UDP, IF and only if you are on a local trusted network)

Now you can even build the AppImage:

1. Install AppImage build dependencies:sudo apt install libfuse2 fuse3 file
2. Move to the AppImage folder and build it:cd AppImage && bash package.sh
3. The result will be under _out.

You can run the ChimeraDesk AppImage executable with ./ChimeraDesk.Appimage - TCP (or UDP, IF and only if you are on a local trusted network)

Build the App on MacOS

1. Install brew
2. Install the required deps: brew install gcc mpv sdl2 sdl2_image sdl2_ttf pkg-config
3. Set the correct env var. according to your installed mpv version, like: export PKG_CONFIG_PATH=/System/Volumes/Data/opt/homebrew/Cellar/mpv/0.35.1_2/lib/pkgconfig/
4. Clone this repo: git clone https://github.com/morrolinux/ChimeraDesk.git
5. Move to the App directory: ChimeraDesk/App/sdl/
6. And build it with: /opt/homebrew/bin/gcc-13 -o main main.c $(pkg-config --libs --cflags mpv sdl2 SDL2_ttf) -std=c99

If everything went fine (no errors) you can now run the program:

1. First you'll need to export DYLD_LIBRARY_PATH=DYLD_LIBRARY_PATH:"/System/Volumes/Data/opt/homebrew/Cellar/mpv/0.35.1_2/lib/"
2. Then run it like so: ./main.

Build the (Remote) KVM component

1. Move to the kvm/Appimage folder: cd ChimeraDesk/kvm/AppImage
2. And build everything into an AppImage like so: bash package.sh
3. The result will be under _out.