# Firewall

**Zoraxy plugin** — Inline WAF inspection proxy with health checks, circuit breaker, and fail-open bypass. Works with Wallarm, ModSecurity, Coraza, or any inspection service that returns HTTP status codes.

---

## Quick Install

The plugin is built into Zoraxy — just enable it from the Plugins panel. If you need to build from source:

```bash
git clone https://git.lohmar.co.uk/cclohmar/zoraxy-waf.git /opt/zoraxy/plugins/zoraxy-waf
cd /opt/zoraxy/plugins/zoraxy-waf
go build -buildvcs=false -o zoraxy-waf .
chown -R zoraxy:zoraxy /opt/zoraxy/plugins/zoraxy-waf
systemctl restart zoraxy
```

Then enable **Firewall** in Zoraxy → Plugins.

---

## Configuration

Open the Firewall panel at `/plugin.ui/zoraxy-firewall/`:

| Setting | Default | Description |
|---------|---------|-------------|
| **Enable** | Off | Toggle WAF inspection on/off |
| **WAF Inspection URL** | `http://127.0.0.1:8080` | Inspection endpoint — receives `POST /inspect` |
| **Return Port** | `8080` | Port for async WAF callbacks/alerts |
| **Health Interval** | `5s` | How often to ping the WAF |
| **Timeout** | `500ms` | Max wait time for a verdict |

---

## How It Works

```
Client → Zoraxy
            │
            ▼
     ┌──────────────────┐
     │  Firewall Plugin  │──► POST http://waf:8080/inspect
     │  (static capture) │    {method, url, headers, body_sample}
     └────┬─────────────┘
          │
     ┌────┴────────────────────────────┐
     │ WAF returns 403                 │ → 280 (BLOCK)    → Request dropped
     │ WAF returns 2xx                 │ → 284 (FORWARD)  → Zoraxy routes to backend
     │ WAF unreachable / breaker OPEN  │ → 284 (FAIL-OPEN)→ Zoraxy routes to backend
     └─────────────────────────────────┘
```

### Circuit Breaker

If the WAF fails 5 times within a 30-second window, the breaker opens. All traffic bypasses inspection (fail-open) for 10 seconds. After the cooldown, the next successful health check closes the breaker.

### Health Check

The plugin periodically sends a `HEAD` request to the WAF URL. If the WAF responds with < 500, the circuit breaker records success. If it fails or returns 5xx, it records a failure.

---

## Inspection Protocol

The plugin sends this JSON payload to `{WAF_URL}/inspect`:

```json
{
  "method": "GET",
  "url": "/some/path",
  "host": "example.com",
  "remote_addr": "10.1.0.5:12345",
  "content_type": "application/json",
  "content_length": 256,
  "headers": {...},
  "body_sample": "<first 4KB of request body>"
}
```

The WAF inspects and returns an HTTP status code:
- **200–299** → Request is clean, Zoraxy forwards to backend
- **403** → Request is malicious, plugin blocks it
- **5xx / timeout** → Plugin fails open, records breaker failure

Any WAF that accepts a POST and returns the appropriate status code is compatible. No special Wallarm integration required.

---

## Zoraxy Integration

To activate the plugin for specific proxy rules:

1. Zoraxy → Plugins → enable **Firewall**
2. Create a plugin group (e.g., "waf") → add the Firewall plugin
3. Edit proxy rules → add the "waf" tag

The plugin uses Zoraxy's **static capture** to intercept all requests matched by tagged proxy rules.

---

## API Endpoints

| Method | Path | Purpose |
|--------|------|---------|
| `GET` | `/ui/api/config` | Get current configuration |
| `POST` | `/ui/api/config/save` | Save configuration |
| `GET` | `/ui/api/stats` | Inspect/bock/bypass metrics + breaker state |
| `POST` | `/inspect` | Static capture — Zoraxy sends traffic here |
| `POST` | `/verdict` | Return port — WAF sends async callbacks here |

---

## Architecture

```
/opt/zoraxy/plugins/zoraxy-waf/
├── zoraxy-waf              # Compiled plugin binary
├── waf_config.json          # Runtime configuration (auto-created)
├── config.go                # Config load/save (thread-safe)
├── main.go                  # Plugin entry, UI router, return listener
├── middleware.go             # Inspection handler + metrics
├── proxy.go                 # WAF HTTP client (body sample + request forwarding)
├── circuit_breaker.go       # Fail-open state machine
├── health.go                # Background health check goroutine
├── web/                     # Config panel UI
│   ├── index.html
│   ├── style.css
│   └── app.js
├── cmd/mockwallarm/         # Test mock WAF server
└── zoraxy_plugin/           # Vendored Zoraxy plugin SDK (LGPL)
```

---

## Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| *none* | — | All config is managed through the UI and persisted to `waf_config.json` |

---

## License

Zoraxy plugin SDK is LGPL. This plugin is open source.

---

## Credits

- [Zoraxy](https://github.com/tobychui/zoraxy) — Reverse proxy and plugin system
- Compatible with any WAF that returns HTTP verdicts (Wallarm, ModSecurity, Coraza, custom)