# badnet
Simulate bad network conditions in Rust integration tests using Linux `tc-netem`.
Each `BadNet` instance provisions a loopback address pair wired through a configurable netem qdisc. Traffic sent between the two addresses passes through the impairment rules. Everything is cleaned up when the handle is dropped.
## Usage
```rust
use std::time::Duration;
use badnet::BadNet;
let net = BadNet::builder()
.seed(42) // reproducible pattern across runs
.loss(0.10) // 10% packet loss
.corrupt(0.02) // 2% bit-flip (appears as loss at the socket layer)
.duplicate(0.05) // 5% duplication
.delay(Duration::from_millis(50))
.reorder(0.20) // 20% of packets skip the delay and arrive early
.build()?;
// Bind sockets to the two ends and communicate normally.
let tx = UdpSocket::bind(format!("{}:0", net.left_addr()))?;
let rx = UdpSocket::bind(format!("{}:9000", net.right_addr()))?;
```
`reorder` requires `delay`. `gap` (periodic deterministic reorder) requires both:
```rust
let net = BadNet::builder()
.delay(Duration::from_millis(20))
.reorder(1.0)
.gap(5) // every 5th packet is sent immediately
.build()?;
```
## Requirements
Linux only. Requires `CAP_NET_ADMIN`. Grant it with `setcap` or run as root:
```sh
sudo setcap cap_net_admin+eip target/debug/deps/<test_binary>
```