blekin/README.md

blekin

A Rust proxy that translates the Belkin OmniView Remote IP Manager's proprietary e-RIC RFB protocol (Peppercon LARA, originally served via a Java applet) into a modern HTML5 KVM console. No Java anywhere in the stack.

What it does

Browser (Vite + TypeScript)
   │ WebSocket (binary, RGBA blits + input events)
   ▼
blekin proxy (Rust, tokio + axum)
   │ HTTP session (cookie + APPLET_ID extraction)
   │ TCP to OmniView:443 (e-RIC RFB)
   ▼
Belkin OmniView Remote IP Manager → downstream KVM switch → servers

The proxy authenticates with the OmniView's web interface, establishes an e-RIC RFB session over TCP, decodes the proprietary 8bpp protocol to RGBA, and bridges video frames and input events to a browser-based console over WebSocket.

Features

• Full KVM console: keyboard, mouse, scroll wheel
• Encodings: Raw, CopyRect, Hextile, Tight (with zlib), IIP tile cache, Raw-tile
• Send Key menu for browser-intercepted keys (Print Screen, Scroll Lock, etc.)
• Port switching with downstream KVM support (Avocent OSCAR tested)
• Port configuration: naming, hotkeys, visibility
• Auto-reconnect with exponential backoff
• Session persistence across page refreshes
• Dark theme, fullscreen mode

Building

# Backend
cargo build --release -p ericrfb-proxy

# Frontend
cd crates/ericrfb-frontend
npm ci
npm run build   # outputs to ../../dist/

Configuration

The proxy reads config.toml or falls back to the BLEKIN_HOST environment variable:

bind = "0.0.0.0:3000"
static_dir = "dist"

[omniview]
host = "10.3.0.130"
http_port = 80
rfb_port = 443

Deployment

The systemd unit runs the proxy as a service. Nginx serves the static frontend and reverse-proxies /api/ to the proxy:

# Backend
sudo cp target/release/ericrfb-proxy /usr/local/bin/
sudo cp asset/systemd/blekin.service /etc/systemd/system/
sudo systemctl enable --now blekin.service

# Frontend
sudo cp -r dist/* /var/www/blekin.example.com/
sudo cp asset/nginx/blekin.example.conf /etc/nginx/sites-available/
sudo ln -sf /etc/nginx/sites-available/blekin.example.conf /etc/nginx/sites-enabled/
sudo nginx -t && sudo systemctl reload nginx

Port switching with downstream KVM

The Belkin OmniView can control a downstream KVM switch (e.g., Avocent AutoView) by sending configurable hotkey sequences when switching ports. Configure these in the Ports page of the blekin interface.

Avocent OSCAR setup

The Avocent OSCAR menu is invoked with Print Screen, then expects the port's EID (Electronic ID) typed as digits, followed by Enter. Each phase needs a pause to let the OSCAR process the input.

Recommended settings:

• Key pause: 1000 ms (in the Ports page global settings)
• Hotkey format: PRINTSCREEN-***<EID digits>-***ENTER

The * character inserts a pause of the configured duration. Three *** = 3 seconds, which gives the OSCAR reliable processing time.

Examples (with key pause = 1000ms):

Server	Avocent EID	Hotkey
server-a	01	PRINTSCREEN-***1-***ENTER
server-b	05	PRINTSCREEN-***5-***ENTER
server-c	17	PRINTSCREEN-***1-7-***ENTER
server-d	22	PRINTSCREEN-***2-2-***ENTER
server-e	31	PRINTSCREEN-***3-1-***ENTER

Note: don't type the leading zero in EIDs (per Avocent OSCAR convention).

Hotkey syntax reference

The Belkin hotkey syntax uses key names connected by operators:

Operator	Meaning
+	Press additionally (hold previous, press next)
-	Release all pressed keys
>	Release most recently pressed key only
*	Pause for the configured key pause duration

Key names: A-Z, 0-9, F1-F12, PRINTSCREEN, ENTER, ESCAPE, LCTRL/CTRL, LALT/ALT, LSHIFT/SHIFT, SPACE, TAB, DELETE, INSERT, HOME, END, PAGE_UP, PAGE_DOWN, UP, DOWN, LEFT, RIGHT, BACK_SPACE, NUM_LOCK, NUMPAD0-NUMPAD9, NUMPADPLUS, NUMPADMINUS, NUMPADMUL, NUMPAD/, NUMPADENTER, SCROLL_LOCK, BREAK, CAPS_LOCK.

Protocol heritage

The e-RIC RFB protocol is a proprietary variant of VNC/RFB developed by Peppercon (later acquired by Raritan) under the name "LARA" (LAN Attached Remote Access). It was used in several KVM-over-IP products including the Belkin OmniView Remote IP Manager (F1DE101H). The protocol shares structural similarities with standard RFB but uses its own handshake, pixel format negotiation, and encoding extensions.

This implementation was reverse-engineered from the CFR-decompiled rc.jar Java applet that originally provided the browser-based console.

License

MIT