hauntstack

"A haunted network simulator"

This is a learning project to implement Layer 2-4 of the Open Systems Interconnection (OSI) model via haunted hardware. A haunted piece of hardware is unpredictable and may fail in many ways. My understanding is that these layers are supposed to be robust even in these conditions.

Parts

• Two network interface cards (NICs) connected via a perfect wire
• Multi-port switch with learning and flooding
• IPv4
• ARP
• UDP
• TCP

Later

• Topology DSL, define endpoints with names/options and wires which connect endpoints
• MAC registry service, start with globally unique MAC addresses
• Tap is an endpoint which simply records what it received
• Set up OTEL tracing for packets and metrics for components

Haunting ideas

• Wires
  • Latency (via event based clock)
  • Loss
  • Corruption
  • Re-ordering (needs a buffer to support this)
  • Bandwidth (via event based clock)
• NIC
  • MAC address change
  • MAC address overlap (via MAC registry)

Local Development

Re-run nix flake check

# Get current system value
$ nix eval --impure --raw --expr 'builtins.currentSystem'
# Get nix store paths we would need to delete to re-run the checks
$ nix path-info .#checks.<system>.ct .#checks.<system>.eunit .#checks.<system>.treefmt
# Delete the store paths from the store
$ nix-store --delete <paths...>
# Re-run the checks, printing the build output and with more verbosity
$ nix flake check -L -v

Potential inspiration

• Simulate bad network connections with comcast
• Chaos engineering for Kubernetes with Chaos Mesh