# Contributing
Thank you for your interest in contributing to ttl!
## Development Setup
### Prerequisites
- Rust 1.88+ (edition 2024)
- Linux or macOS (Windows not currently supported)
- `CAP_NET_RAW` capability or root access for testing
### Building
```bash
git clone https://github.com/lance0/ttl
cd ttl
cargo build
```
### Running
```bash
# Development build
sudo cargo run -- 8.8.8.8
# Or set capability on release binary
cargo build --release
sudo setcap cap_net_raw+ep target/release/ttl
./target/release/ttl 8.8.8.8
```
## Code Style
This project uses standard Rust formatting and linting:
```bash
# Format code
cargo fmt
# Run clippy with warnings as errors
cargo clippy -- -D warnings
```
All PRs must pass:
- `cargo build`
- `cargo test`
- `cargo clippy -- -D warnings`
- `cargo fmt -- --check`
## Testing
```bash
# Run all tests
cargo test
# Run tests with output
cargo test -- --nocapture
```
Note: Many features require raw socket access and are difficult to test in CI. Manual testing is often necessary.
## Project Structure
See [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md) for detailed module documentation.
Key directories:
- `src/probe/` - Packet crafting and ICMP parsing
- `src/trace/` - Probe orchestration and response handling
- `src/state/` - Session and hop state management
- `src/tui/` - Terminal user interface
- `src/lookup/` - ASN, GeoIP, DNS enrichment
- `src/export/` - Output formats (JSON, CSV, report)
## Pull Request Process
1. Fork the repository
2. Create a feature branch from `master`
3. Make your changes
4. Ensure all checks pass (`cargo build && cargo test && cargo clippy -- -D warnings && cargo fmt -- --check`)
5. Submit a pull request
### Commit Messages
- Use clear, descriptive commit messages
- Start with a verb (Add, Fix, Update, Remove, Refactor)
- Keep the first line under 72 characters
Good examples:
- `Add IPv6 support for TCP probes`
- `Fix PMTUD binary search off-by-one error`
- `Update ratatui to 0.30 for security fix`
### What to Include
- **Bug fixes**: Include steps to reproduce and verify the fix
- **New features**: Update README.md and relevant docs
- **Breaking changes**: Note in CHANGELOG.md
## Reporting Issues
When reporting bugs, please include:
- OS and version (e.g., Ubuntu 22.04, macOS 14)
- Rust version (`rustc --version`)
- ttl version (`ttl --version`)
- Steps to reproduce
- Expected vs actual behavior
- Any error messages
## License
By contributing, you agree that your contributions will be licensed under the same dual MIT/Apache-2.0 license as the project.
