Documentation
¶
Overview ¶
Package transport defines the L2 datagram-I/O abstraction the daemon uses for the central tunnel socket.
Today there is one implementation: *udpio.Socket. v1.10.2 introduces a second one — pkg/daemon/transport/wss — that tunnels Pilot packets over a WebSocket Secure connection to the beacon for compat-mode daemons running in UDP-blocked environments (Docker on Render/Railway/Vercel/ Lambda). See docs/SPEC-compat-mode.md.
The interface uses *net.UDPAddr as the address type even for non-UDP transports. The WSS implementation will pass a synthetic address that represents "the beacon" so all of L3+ (tunnel manager, routing manager, dispatch) stays transport-agnostic. The synthetic address is opaque to upper layers — they only key on the source nodeID inside the Pilot packet header, not the wire-level src addr.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrClosed = errors.New("transport: closed")
ErrClosed is the sentinel returned by Transport.Recv after the transport has been Close()d (or a remote close has propagated, for stream-oriented transports like WSS). The readLoop in pkg/daemon checks this with errors.Is to distinguish "I/O error on this frame" (continue + log) from "transport is gone" (exit cleanly).
Both implementations — udpio.Socket and the planned WSS transport — must return ErrClosed (or wrap it) on a closed transport.
Functions ¶
This section is empty.
Types ¶
type Transport ¶
type Transport interface {
// Send writes frame to dst as one datagram. For UDP this is a
// kernel UDPConn.WriteToUDP; for WSS this is a single binary WS
// frame written to the beacon connection (dst is ignored — the
// destination is implicit). Returns bytes-written and the
// underlying error.
Send(frame []byte, dst *net.UDPAddr) (int, error)
// Recv reads one datagram. Returns the frame slice (valid until
// the next Recv call — caller must copy if retaining), the source
// address (real *net.UDPAddr for UDP; synthetic for WSS), and any
// I/O error. On Close, returns the implementation's sentinel
// closed-socket error.
Recv() ([]byte, *net.UDPAddr, error)
// LocalAddr returns the bind address for UDP transports; for WSS
// returns a synthetic address representing the local end of the
// compat tunnel. Never nil for a live transport.
LocalAddr() *net.UDPAddr
// Close releases resources. Idempotent.
Close() error
}
Transport is the L2 read/write interface. Implementations must be safe for one concurrent reader (Recv) and one concurrent writer (Send) — matches the contract today's pkg/daemon/tunnel.go relies on (single readLoop goroutine driving Recv; multiple Send goroutines from L4 routing serialized at the kernel level).
Close is idempotent. After Close, Recv must return a sentinel error the caller can identify (today: udpio.ErrClosed; the WSS transport will return the same error so the read-loop teardown is uniform).
Source Files
Directories