Peers communicating on uncensored networks can benefit from raw WireGuard
performance over direct UDP without QUIC framing or double-encryption
overhead. This provides Tailscale-like direct tunnel performance while
preserving Tsunagi's decentralized mesh architecture.
Key changes:
- Create `tsunagi-wireguard` crate implementing the `IpPlugin` and
`PacketTransport` contracts:
- `WG_PROTOCOL = "wg"` with wire version 1.
- Bounded `WgAnnouncement` carrying WireGuard public keys, listening UDP
ports, and candidate IP addresses (filtering out overlay interfaces).
- `WgKeyStore` managing persistent per-network WireGuard X25519 keys
in SQLite with zeroization on drop.
- `WireguardTransport` providing direct UDP packet transmission, candidate
address tracking, inbound link delivery, and roaming support.
- `WireguardDevice` running userspace WireGuard encryption via `boringtun`,
timer maintenance, and AllowedIPs source enforcement.
- Integrate `wg` into `tsunagi-cli`:
- Set default protocols to `"wg,tcp-tls,wg-quic"` so all protocols are
enabled by default in order of throughput and performance.
- Support `"wireguard"` as a convenience alias for `"wg"` in `--protocol`.
- Bind `PureWgTransport` and launch the inbound datagram accept loop on `up`.
- Pass `pure_wg` plugin to `AgentControl` and update `build_report` so
active WireGuard tunnels and overlay metrics are reported in `tsunagi status`.
- Clean up WireGuard keys on network removal in `forget_protocol_state`.
- Comprehensive test coverage in `tsunagi-wireguard`:
- `announcement_tests`: round-trip serialization and verification of malformed,
mismatched network, zero port, or self-claiming announcements.
- `transport_tests`: loopback UDP link delivery between transports.
- `plugin_tests`: end-to-end two-peer handshake and bidirectional IP packet
transit over direct UDP.
Validation on Linux:
- cargo fmt --all -- --check passed.
- cargo clippy --locked --workspace --all-targets -- -D warnings passed.
- cargo test --locked --workspace --all-targets passed.
