RustShield Modbus Gateway v0.1.0 Lab Preview

RustShield Modbus Gateway v0.1.0 Lab Preview publishes the first public proof of concept for stateful semantic filtering of Modbus TCP traffic in a local OT/ICS lab simulation.

What Is Included

• Transparent Rust/Tokio TCP proxy for Modbus TCP traffic.
• Strict MBAP/PDU framing and validation.
• Passive observation of read responses for process-state tracking.
• Stateful policy decisions for a protected Write Single Coil command.
• Fail-safe blocking for unknown, stale, unsafe, or unsupported write paths.
• Read-only local health and Prometheus-style metrics.
• Reproducible loopback evidence with a synthetic PLC simulator.
• Grafana/Prometheus demo assets for local visualization.

Validation

• cargo fmt
• cargo test: 26 tests passing
• cargo check
• cargo clippy --all-targets --all-features -- -D warnings
• public-showcase sanitization scan for internal/private references

Scope And Safety Boundaries

• Proof of concept only.
• Local loopback simulation only.
• No real PLC validation.
• No production OT safety or security certification.
• No cryptographic authentication claim.
• Not a replacement for segmentation, access control, hardening, key management, or OT risk governance.