Commit Graph
4 Commits
Author SHA1 Message Date
Aleksandr Bogomiakov 35acc4d231 Fix WireGuard relay preemption with UDP probing, allow VM bridges, and categorize status addresses
When remote peers communicate across networks with mixed connectivity (e.g.
a remote Linux node, a local Linux host, and a Windows VM guest under KVM):
- Previously, `WireguardTransport` immediately created and installed
  unverified direct links into `RelayHub` in `notify_peer_capability` and
  `open()`. When a remote peer had only unroutable private addresses
  (e.g. 192.168.122.151 on a KVM NAT bridge), this dead direct link
  preempted the working 2-hop relay, causing packet drops, failed handshakes,
  and REKEY_TIMEOUT errors.
- Host-guest VM bridges (`virbr*`) were previously filtered out, preventing
  the VM guest from discovering the host's bridge IP (192.168.122.1) and
  forcing it to attempt cross-interface connections to host Wi-Fi/LAN.
- Concurrent activation of multiple networks sharing one `tsun0` interface
  raced in `sync_addresses`, resulting in netlink `File exists (os error 17)`
  and `The object already exists` on Windows.

Key fixes:
- In `crates/tsunagi-wireguard/src/transport.rs`:
  - Implement bidirectional UDP probing with `TSUNAGI_WG_PROBE_V1` PING/PONG.
  - In `open()`, probe candidate endpoints with retransmission up to 1200ms.
    If unreachable, return `TransportError::Unreachable`, preventing dead
    links from preempting valid relay routes in `RelayHub`.
  - In `notify_peer_capability`, send hole-punching probes without prematurely
    installing unverified links.
  - In `accept_loop`, reply to PING probes with PONG and install confirmed
    inbound links targeting the verified source address.
  - In `WireguardLink::send`, inspect byte 74 of enveloped packets to detect
    handshake initiations, ensuring confirmed links route data packets only
    to the active target.
- In `crates/tsunagi-wireguard/src/plugin.rs`:
  - Permit VM bridges (`virbr*`) as candidate interfaces (priority 10).
  - Add `prioritize_local_subnet` to prioritize candidates sharing a local
    IPv4 subnet with the receiver (e.g. 192.168.122.0/24).
- In `crates/tsunagi/src/overlay/interface.rs` & provisioners:
  - Add async mutex `sync_lock` to serialize concurrent address syncs across networks.
  - Handle netlink EEXIST (os error 17) and Windows already-exists errors
    idempotently as success.
- In `crates/tsunagi-cli/src/main.rs`:
  - Split `local addresses` in `tsunagi status` into `announced` (candidate
    addresses in priority order with interface and rank), `not announced`
    (container bridges/internal addresses with interface name), and `loopback`.
- Tests:
  - Add `test_wireguard_transport_unreachable_probe_times_out` and
    `test_matches_subnet` unit tests.

Validation on Linux:
- cargo fmt --all -- --check passed.
- cargo clippy --locked --workspace --all-targets -- -D warnings passed.
- cargo test --locked --workspace --all-targets passed (350+ tests passed).
2026-10-01 02:38:13 +01:00
Aleksandr Bogomiakov c791102ad9 Fix overlay and virtual interface candidate leakage and WireGuard rekeying
On Windows (Wintun), iface.name in netdev is an adapter GUID, while
iface.friendly_name is 'tsun0'. Checking only iface.name failed to
identify and exclude Wintun overlay interfaces. Consequently, Windows
nodes announced their own overlay IP addresses (e.g. 10.13.37.26) as
candidate endpoints. Remote peers latched onto this overlay IP as the
WireGuard target, routing encrypted packets into tsun0 (recursive loop),
resulting in failed handshakes and subsequent HANDSHAKE(REKEY_TIMEOUT)
and CONNECTION_EXPIRED.

Similarly, Docker bridges (br-*, docker0) and virtual bridges were
announced and alphabetically sorted before physical LAN or Tailscale
interfaces, causing peers to attempt WireGuard handshakes with internal
Docker bridge addresses (e.g. 172.21.0.1).

Key changes:
- In crates/tsunagi-wireguard and crates/tsunagi-tcp-tls:
  - Robustly identify overlay interfaces by inspecting iface.name,
    iface.friendly_name, and iface.description for 'tsun', 'tsunagi',
    and 'wintun'.
  - Filter out container and virtual bridge interfaces (docker, br-,
    veth, virbr, cni, flannel, cali, kube, dummy, lxc, podman, vethernet,
    vboxnet, vmnet).
  - Prioritize candidates by physical interface score: interfaces with
    a default gateway (physical LAN/WAN) and Tailscale (100.64.0.0/10)
    score highest and sort to candidate #0.
  - In on_peer_capability, filter out any announced address falling inside
    any active overlay IPv4 range (defense in depth on receiver).
- In crates/tsunagi-wireguard/src/transport.rs:
  - In WireguardLink::send, broadcast Handshake Initiation packets (type 1)
    to all candidate addresses so initial handshakes and rekeys probe all
    candidate paths and recover if an endpoint roamed or NAT expired.
  - In accept_loop, prioritize exact socket address matches before falling
    back to candidate IP matches for NAT port roaming.
- In crates/tsunagi/src/net.rs:
  - Update iroh AddrFilter to inspect friendly_name and description,
    preventing Wintun overlay IPs from leaking into iroh discovery endpoints.
- Tests:
  - Add unit tests for candidate interface filtering, IP validation, and
    priority scoring in tsunagi-wireguard and tsunagi-tcp-tls.

Validation on Linux:
- cargo fmt --all -- --check passed.
- cargo clippy --locked --workspace --all-targets -- -D warnings passed.
- cargo test --locked --workspace --all-targets passed (350+ tests passed).
2026-10-01 02:15:06 +01:00
Aleksandr Bogomiakov f80841da63 Fix WireGuard multi-network demux, candidate discovery, and status reporting
When a peer belongs to multiple overlay networks served by one agent (e.g.
a VM participating in both 'hexor' and 'ultradesu'), packets received on
the shared WireGuard UDP socket could not be differentiated by source IP/port
alone. Previously, `WireguardTransport::accept_loop` picked the first
matching link found in iteration order, starving other networks for that peer
and causing rekey timeouts (`WARN HANDSHAKE(REKEY_TIMEOUT)`,
`ERROR CONNECTION_EXPIRED(REKEY_ATTEMPT_TIME)`) and packet loss on the
starved network.

Additionally:
- When a peer had multiple candidate endpoints (such as LAN, VM bridge, and
  Tailscale CGNAT addresses), `WireguardLink` sent handshake initiations
  only to `addrs[0]`. If the first address was unreachable from the remote
  side (e.g. host's Tailscale IP unreachable from inside a local VM), the
  handshake never completed.
- In `build_report`, peers known to the `wg-quic` plugin were added with
  empty tunnels even if an active `wg` (pure WireGuard) tunnel existed,
  causing `tsunagi status` to falsely report 'no WireGuard handshake yet'
  for connected and pingable peers.
- `local_ip_candidates` previously included IPv6 addresses which caused
  OS error 22 (EINVAL) when passed to the IPv4-bound UDP socket.

Key fixes:
- In `crates/tsunagi-wireguard/src/transport.rs`:
  - Store `peer_networks` as `HashSet<NetworkId>` per peer.
  - In `WireguardLink`, maintain a list of candidate addresses and a
    `confirmed` flag. Before a handshake response confirms the active path,
    transmit datagrams (handshake initiations) to all candidate addresses.
    Upon receiving an inbound datagram, lock onto the confirmed address.
  - In `accept_loop`, deliver inbound datagrams to all active links
    associated with the sender's endpoint ID across all networks. Boringtun's
    cryptographic index and AEAD verification naturally demultiplexes and
    accepts the packet in the correct network while discarding it in others.
  - Filter candidate addresses to IPv4 to match the bound socket family.
- In `crates/tsunagi-wireguard/src/plugin.rs`:
  - Only collect IPv4 interfaces in `local_ip_candidates`.
- In `crates/tsunagi-cli/src/main.rs`:
  - Refactor `build_report` to evaluate all protocols per peer and prioritize
    whichever protocol has an active tunnel (`wg` > `tcp-tls` > `wg-quic`).
- In `crates/tsunagi-wireguard/tests/plugin_tests.rs`:
  - Add `test_wireguard_two_networks_same_peers` verifying simultaneous
    bidirectional packet transmission between two peers sharing two networks
    over a single `WireguardTransport`.

Validation on Linux:
- cargo fmt --all -- --check passed.
- cargo clippy --locked --workspace --all-targets -- -D warnings passed.
- cargo test --locked --workspace --all-targets passed (350+ tests passed).
2026-10-01 01:38:44 +01:00
Aleksandr Bogomiakov 7070a16104 Add pure WireGuard direct UDP data plane plugin and transport
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.
2026-10-01 01:24:25 +01:00