Add link_mtu(&TransportAddr) method to the Transport trait with a
default implementation that falls back to the transport-wide mtu().
This enables transports like BLE to report per-connection MTU values
while maintaining backward compatibility for UDP and other transports
that use a single MTU for all links.
Update the forwarding and session send paths to query link_mtu() with
the next-hop peer's current address, falling back to transport-wide
mtu() when no address is available.
Log a warning when the kernel clamps SO_RCVBUF or SO_SNDBUF below
the requested size, directing the operator to increase rmem_max or
wmem_max. Document buffer size defaults and sysctl requirements in
the Docker config template.
Under high-throughput forwarding, the kernel default 212KB receive
buffer overflows, silently dropping ~11% of UDP datagrams at transit
nodes. Add configurable recv_buf_size and send_buf_size to UdpConfig
(default 2MB each) using socket2 for pre-bind buffer configuration.
Startup log now reports actual buffer sizes granted by the kernel.
Requires net.core.rmem_max >= 2097152 on the host for the full 2MB
to take effect; otherwise the kernel silently clamps.
Per-packet happy-path events (UDP send/receive, TUN I/O, MMP report
processing, TreeAnnounce/FilterAnnounce sent, RTT samples) moved from
debug to trace. Periodic maintenance and retry scheduling moved from
info to debug. Session state changes (established, initiated, torn
down) and transport stop promoted from debug to info. MMP report send
failures demoted from warn to debug (normal under churn).
Wire format:
- Add HandshakeMessageType enum (NoiseIKMsg1=0x01, NoiseIKMsg2=0x02)
- Define unified TLV framing for handshake and post-handshake messages
- Update fips-design.md and fips-protocol-flow.md with wire format details
Initialization:
- Defer TUN setup until after peer connections initiated
- Order: packet channel → transports → peers → TUN
Logging cleanup:
- Consolidate node/TUN info logs into aligned multi-line format
- TUN shutdown: single start/stop message, remove intermediate noise
- Remove ip link show callout and redundant Starting node message
- Change UDP transport stopped to debug level
- Add name field to UdpTransport for named config instances
- Add name() and local_addr() accessors to TransportHandle
- Update UdpTransport logging to include instance name
- Remove redundant Node-level transport startup logging
- Reorder Node::start() to initialize transports before TUN
- Added TransportHandle enum for polymorphic transport dispatch
- Node now owns transports via HashMap<TransportId, TransportHandle>
- Added packet channel fields (packet_tx, packet_rx) to Node
- Transport initialization in Node::start() with graceful degradation
- Transport shutdown in Node::stop() before TUN cleanup
- Factory method create_transports() instantiates from config
Configuration redesign:
- New transports section with TransportInstances<T> enum
- Single instance: config directly under transport type (no naming overhead)
- Named instances: nested under instance names
- #[serde(deny_unknown_fields)] ensures correct untagged enum matching
- Instance names are Option<&str> - None for single, Some(name) for named
Updated Node transport methods:
- transport_count(), get_transport(), get_transport_mut()
- transport_ids(), packet_rx()
All 189 tests pass (4 new config parsing tests).
- Convert transport.rs to module directory (transport/mod.rs + transport/udp.rs)
- Add packet channel types for transport→Node communication:
- ReceivedPacket struct with transport_id, remote_addr, data, timestamp
- PacketTx/PacketRx type aliases for tokio mpsc channels
- packet_channel() constructor function
- Add UdpConfig to config.rs (enabled, bind_addr, mtu)
- Implement UdpTransport with async lifecycle:
- start_async(): binds socket, spawns receive loop
- stop_async(): aborts receive task, closes socket
- send_async(): sends packet with MTU validation
- discover(): returns empty (peer config is node-level)
- Update lib.rs with new re-exports
- Add tokio net and time features to Cargo.toml
All 185 tests pass.
Johnathan Corgan