Commit Graph
4 Commits
Author SHA1 Message Date
Aleksandr Bogomiakov 3930dff2dc Detect WireGuard tunnel rekey failure and trigger automatic fallback
Previously, because UDP is connectionless, when a pure WireGuard tunnel
encountered handshake or rekey failures (e.g. boringtun logging
`WARN HANDSHAKE(REKEY_TIMEOUT)` and `CONNECTION_EXPIRED`), the
`WireguardLink` never closed. It remained active in `agent.links` and
as a direct hop in `RelayHub.raw`. Consequently, outgoing packets
continued to be blackholed over the dead direct path, preventing
`RelayHub` from using working multihop relay routes and preventing
the agent from falling back to alternative protocols (`tcp-tls` or
`wg-quic`).

Key changes:
- In `crates/tsunagi-wireguard/src/device.rs`:
  - In `FlowTunnel`, track active handshake and rekey attempts via
    `handshake_started_at`. If an active handshake attempt remains
    unanswered beyond `HANDSHAKE_TIMEOUT` (15s) or boringtun reports
    `ConnectionExpired`, declare the tunnel dead.
  - Reset timeout timers upon successful handshake reception in
    `decapsulate`.
  - In `drive_timers`, when tunnel failure is detected, trigger
    `inner.on_tunnel_failed(peer)`, which closes the direct transport
    link and notifies the agent via `PluginContext::report_peer_protocol_failure`.
- In `crates/tsunagi-wireguard/src/transport.rs`:
  - Add `WireguardLink::close` to transition `is_closed` to true and
    notify `closed_notify`.
  - In `WireguardLink::recv`, select on `closed_notify` so readers
    unblock and return `None` immediately on close.
  - Add `WireguardTransport::close_link` to close active links by
    network and peer.
- In `crates/tsunagi/src/dataplane/mod.rs`:
  - Add `PluginRequest::ProtocolFailure` and public helper
    `PluginContext::report_peer_protocol_failure`.
- In `crates/tsunagi/src/agent/mod.rs` and `crates/tsunagi/src/agent/network.rs`:
  - Add `NetCommand::ProtocolFailure` to runtime command handling.
  - On protocol failure: remove dead direct link from `self.links`,
    clear it from `RelayHub.raw` (so `RelayHub` immediately routes
    over available multihop relays), record failure on `wg` for that
    peer with exponential backoff cooldown, emit `DataLinkDown`, and
    immediately call `ensure_links()` to dial the next mutually supported
    protocol (`tcp-tls` or `wg-quic`).
- Tests:
  - Add `test_flow_tunnel_rekey_timeout_triggers_failure` and
    `test_flow_tunnel_reset_on_handshake` unit tests in `device.rs`.
  - Add `test_wireguard_link_close_and_transport_close_link` in
    `transport_tests.rs`.
  - Add `test_protocol_dial_state_cooldown_and_fallback_selection` in
    `network.rs`.

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).
- Built release binary: target/release/tsunagi.
2026-10-01 03:02:09 +01:00
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 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