Method OnConnect

internal/handler/forwarder.go:34–84

OnConnect establishes a UDP session to the backend.

(ctx *Context)

// OnConnect establishes a UDP session to the backend.
func (h *ForwarderHandler) OnConnect(ctx *Context) Result {
	// Get backend from context (set by router handler)
	backend := ctx.GetString("backend")
	if backend == "" {
		return Result{Action: Drop, Error: errors.New("no backend address")}
	}

	// Resolve backend address
	backendAddr, err := net.ResolveUDPAddr("udp", backend)
	if err != nil {
		return Result{Action: Drop, Error: err}
	}

	// Create UDP connection to backend
	backendConn, err := net.DialUDP("udp", nil, backendAddr)
	if err != nil {
		return Result{Action: Drop, Error: err}
	}

	// Create session
	now := time.Now()
	session := &Session{
		ID:          h.sessionCounter.Add(1),
		BackendAddr: backendAddr,
		BackendConn: backendConn,
		CreatedAt:   now,
	}
	session.SetClientAddr(ctx.ClientAddr)
	session.LastActivity.Store(now.Unix())
	ctx.Session = session

	log.Printf("[forwarder] session=%d %s -> %s", session.ID, ctx.ClientAddr, backend)

	// Forward the initial packet to backend
	if len(ctx.InitialPacket) > 0 {
		_, err := backendConn.Write(ctx.InitialPacket)
		if err != nil {
			log.Printf("[forwarder] failed to forward initial packet: %v", err)
			backendConn.Close()
			return Result{Action: Drop, Error: err}
		}
	}

	// Clear InitialPacket to free memory (~1.4KB per session)
	ctx.InitialPacket = nil

	// Start goroutine to read from backend and send to client
	go h.backendToClient(ctx, session)

	return Result{Action: Handled}
}

// OnPacket forwards packets from client to backend.
func (h *ForwarderHandler) OnPacket(ctx *Context, packet []byte, dir Direction) Result {