# Moblink (Rust🦀 edition)
Use spare devices as extra SRTLA bonding connections. The same functionality is part of [Moblin](https://github.com/eerimoq/moblin) on iOS.
Originally inspired by the Moblink Kotlin/Android code.
## Features
- **WebSocket Connection**: Connects to Moblin via WebSocket (e.g., `wss://...`)
- **Auth Handling**: Implements the same challenge–response authentication logic as the Android client
- **UDP Relay**: Forwards UDP packets between the remote streamer and a local destination.
- **mDNS**: Automatically connect to nearby Moblink devices.
## Requirements
- **Rust** (stable, e.g., 1.85+)
- **Cargo** (for building)
## Usage
### Use on Belabox
```bash
ssh user@belabox.local
```
password: See belabox under advanced / developer
ssh to your belabox and run this:
```bash
Then start a Moblink relay and open <http://belabox.local/> in your browser.
If not, make sure your relay has a short name. At most ~10 characters
--> Make sure the password is "1234" and put it on AUTO on the android phone.
### Build
```bash
# 1. Clone this repository (or copy the code)
git clone https://github.com/datagutt/moblink-rust.git
cd moblink-rust
# Set nightly (optional)
rustup override set nightly
# 2. Build the project
cargo build --release
```
### Run Relay
```bash
./target/release/moblink-relay \
--name "RelayName" \
--id "UUID" \
--streamer-url ws://192.168.1.2:7777 \
--password "secret123" \
--bind-address 192.168.1.10
--log-level debug
```
#### Command-Line Arguments
| `--name` | Name to identify the relay | Hostname | `--name CameraRelay1` |
| `--id` | UUID to identify the Relay | Generated | `--id UUID` |
| `--streamer-url` | WebSocket URL to connect to the streamer | _None_ (multicast DNS) | `--streamer-url wss://example.com/ws` |
| `--password` | Password used in the challenge–response authentication | `1234` | `--password mySecret` |
| `--log-level` | Logging verbosity (e.g., error, warn, info, debug, trace) | `info` | `--log-level debug` |
| `--bind-address` | Local modem IP address to bind for UDP socket | `0.0.0.0` | `--bind-address 192.168.1.10` |
| `--status-executable` | Status executable. Print status to standard output on format {"batteryPercentage": 93} | _None_ | `--status-executable ./status.sh` |
| `--status-file` | Status file. Contains status on format {"batteryPercentage": 93} | _None_ | `--status-file status.json` |
Relay status (today only battery percentage) is sent to the streamer if `--status-executable` or `--status-file` is given and outputting a valid JSON object as seen above.
### Run Relay Service
`moblink-relay` connects a single network interface. `moblink-relay-service` is a supervisor that watches every eligible network interface and starts one relay per interface automatically. It is useful on machines with several uplinks (for example a router with Ethernet, Wi-Fi, and cellular), where each uplink becomes an independent bonding path.
```bash
./target/release/moblink-relay-service \
--password "secret123" \
--interface-name-override eth0=WAN \
--interface-name-override wwan0=LTE \
--runtime-status-file /tmp/moblink-relay-status.json
```
By default the service discovers streamers over multicast DNS. Pass one or more `--streamer-url` to connect to fixed streamers instead, which is helpful where multicast DNS is unreliable (for example across router uplinks behind NAT).
#### Command-Line Arguments
| `--password` | Password used in the challenge response authentication | `1234` | `--password mySecret` |
| `--network-interfaces-to-allow` | Regex of interface names to allow (`^`/`$` anchors added automatically). Repeatable. Localhost is never allowed. | _All_ | `--network-interfaces-to-allow 'eth.*'` |
| `--network-interfaces-to-ignore` | Regex of interface names to ignore (`^`/`$` anchors added automatically). Repeatable. | _None_ | `--network-interfaces-to-ignore 'docker.*'` |
| `--streamer-url` | Connect to this streamer URL directly instead of discovering over multicast DNS. Repeatable. | _None_ (multicast DNS) | `--streamer-url ws://192.168.1.2:7777` |
| `--interface-name-override` | Rename the relay shown in the Moblin app for a given interface, as `interface=label`. Repeatable. | _None_ | `--interface-name-override eth0=WAN` |
| `--runtime-status-file` | Write relay and streamer state as JSON to this file, for external UIs to display connection status and streamer IPs. | _None_ | `--runtime-status-file status.json` |
| `--status-executable` | Status executable. Print status to standard output on format {"batteryPercentage": 93} | _None_ | `--status-executable ./status.sh` |
| `--status-file` | Status file. Contains status on format {"batteryPercentage": 93} | _None_ | `--status-file status.json` |
| `--database` | File storing the per-interface relay identities | `moblink-relay-service.json` | `--database /etc/moblink/relays.json` |
| `--log-level` | Logging verbosity (e.g., error, warn, info, debug, trace) | `info` | `--log-level debug` |
The runtime status file is rewritten whenever relays or streamers change. It contains a JSON object with `connected`, `manual_streamer`, a `streamers` array, and a `relays` array (each relay reporting its interface name, interface address, and the streamer name, URL, and host it serves).
### Run Streamer
```bash
./target/release/moblink-streamer \
--websocket-server-address 192.168.1.2 \
--destination-address 172.120.50.214 \
--destination-port 5000
```
#### Command-Line Arguments
| `--name` | Name to identify the streamer | Hostname | `--name CameraRelay1` |
| `--id` | Id to identify the streamer using multicast DNS | Hostname | `--id UUID` |
| `--password` | Password used in the challenge–response authentication | `1234` | `--password mySecret` |
| `--log-level` | Logging verbosity (e.g., error, warn, info, debug, trace) | `info` | `--log-level debug` |
| `--websocket-server-address` | Local IP address to bind websocket server to | | `--websocket-server-address 192.168.1.10` |
| `--websocket-server-port` | Local port to bind the websocket server to | `7777` | `--websocket-server-port 7778` |
| `--tun-ip-network` | TUN IP network (CIDR notation). TUN network interfaces will be assigned IP addresses from this network. | `10.3.3.0/24` | `--tun-ip-network 10.1.1.0/24` |
| `--destination-address` | Streaming destination address | | `--status-file status.json` |
| `--destination-port` | Streaming destination port | | `--status-file status.json` |
## Relay Architecture
1. **WebSocket Connection**
- Establishes a WebSocket to `streamer_url`, or if not provided, tries to find nearby Moblink streamers through multicast DNS.
- Handles “Hello” messages, calculates authentication, and sends an “Identify” message.
2. **Handling Requests**
- When a `startTunnel` request is received, the relay spawns two async tasks:
- **(relay_to_destination)**: Forwards traffic from streamer → destination
- **(relay_to_streamer)**: Forwards traffic from destination → streamer
3. **UDP Binding**
- By default, it binds a UDP socket to whatever we deem to be the main network interface.
## FAQ
**Q:** How do I integrate this into my own application?
**A:** Use the moblink-rust [crate](https://crates.io/crates/moblink-rust)
---
**License**: This project is distributed under the terms of the MIT license.
Enjoy using **Moblink**!