flatten tio.Capabilities

overlay/overlaytest/noop.go

@@ -15,6 +15,10 @@ import (
 // exercise the datapath.
 type NoopTun struct{}
 
+func (NoopTun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (NoopTun) RoutesFor(addr netip.Addr) routing.Gateways {
 	return routing.Gateways{}
 }

overlay/tio/tio.go

@@ -34,15 +34,16 @@ type Queue interface {
 	// Read returns one or more packets. The returned Packet.Bytes slices
 	// are borrowed from the Queue's internal buffer and are only valid
 	// until the next Read or Close on this Queue - callers must encrypt
-	// or copy each slice before the next call. A Packet may carry a
-	// GSO/USO superpacket (see GSOInfo); when GSO.IsSuperpacket() is
-	// true the caller must segment Bytes before treating it as a single
-	// IP datagram. Not safe for concurrent Reads.
+	// or copy each slice before the next call.
 	Read() ([]Packet, error)
 
 	// Write emits a single packet on the plaintext (outside→inside)
 	// delivery path. Not safe for concurrent Writes.
 	Write(p []byte) (int, error)
+
+	// Capabilities returns the Queue's negotiated offload capabilities,
+	// or the zero value when q does not advertise any.
+	Capabilities() Capabilities
 }
 
 // Packet is the unit Queue.Read returns. Bytes points into the queue's
@@ -79,38 +80,6 @@ type GSOInfo struct {
 // and sent on the wire.
 func (g GSOInfo) IsSuperpacket() bool { return g.Size > 0 }
 
-// Clone returns a Packet whose Bytes is a freshly allocated copy of p.Bytes,
-// safe to retain past the next Read or Close on the originating Queue.
-// GSO metadata is copied verbatim. Use this only when a caller genuinely
-// needs to outlive the borrowed-slice contract — the hot path reads should
-// continue to consume the borrow synchronously to avoid the allocation.
-func (p Packet) Clone() Packet {
-	if p.Bytes == nil {
-		return p
-	}
-	cp := make([]byte, len(p.Bytes))
-	copy(cp, p.Bytes)
-	return Packet{Bytes: cp, GSO: p.GSO}
-}
-
-// CapsProvider is an optional interface implemented by Queues that
-// successfully negotiated kernel offload features at open time. Callers
-// pick a write-path coalescer based on the result. Queues that don't
-// implement it are treated as having no offload capability — callers must
-// fall back to plain per-packet writes.
-type CapsProvider interface {
-	Capabilities() Capabilities
-}
-
-// QueueCapabilities returns q's negotiated offload capabilities, or the
-// zero value when q does not advertise any.
-func QueueCapabilities(q Queue) Capabilities {
-	if cp, ok := q.(CapsProvider); ok {
-		return cp.Capabilities()
-	}
-	return Capabilities{}
-}
-
 // GSOProto selects the L4 protocol for a GSO superpacket. Determines which
 // VIRTIO_NET_HDR_GSO_* type the writer stamps and which checksum offset
 // inside the transport header virtio NEEDS_CSUM expects.

overlay/tun_android.go

@@ -128,3 +128,7 @@ func (t *tun) NewMultiQueueReader() error {
 func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
+
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}

overlay/tun_darwin.go

@@ -573,3 +573,7 @@ func (t *tun) NewMultiQueueReader() error {
 func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
+
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}

overlay/tun_disabled.go

@@ -33,6 +33,10 @@ type disabledQueue struct {
 	batchRet [1]tio.Packet
 }
 
+func (q *disabledQueue) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (q *disabledQueue) Read() ([]tio.Packet, error) {
 	r, ok := <-q.parent.read
 	if !ok {

overlay/tun_freebsd.go

@@ -609,6 +609,10 @@ func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
 
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (t *tun) removeRoutes(routes []Route) error {
 	for _, r := range routes {
 		if !r.Install {

overlay/tun_ios.go

@@ -184,3 +184,7 @@ func (t *tun) NewMultiQueueReader() error {
 func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
+
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}

overlay/tun_netbsd.go

@@ -84,6 +84,10 @@ func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
 
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 var deviceNameRE = regexp.MustCompile(`^tun[0-9]+$`)
 
 func newTunFromFd(_ *config.C, _ *slog.Logger, _ int, _ []netip.Prefix) (*tun, error) {

overlay/tun_openbsd.go

@@ -383,6 +383,10 @@ func (t *tun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
 
+func (t *tun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func addRoute(prefix netip.Prefix, gateways []netip.Prefix) error {
 	sock, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
 	if err != nil {

overlay/tun_tester.go

@@ -197,6 +197,10 @@ func (t *TestTun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
 
+func (t *TestTun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (t *TestTun) SupportsMultiqueue() bool {
 	return false
 }

overlay/tun_windows.go

@@ -284,6 +284,10 @@ func (t *winTun) Readers() []tio.Queue {
 	return []tio.Queue{t}
 }
 
+func (t *winTun) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (t *winTun) Close() error {
 	// It seems that the Windows networking stack doesn't like it when we destroy interfaces that have active routes,
 	// so to be certain, just remove everything before destroying.

overlay/user.go

@@ -42,6 +42,10 @@ type UserDevice struct {
 	batchRet [1]tio.Packet
 }
 
+func (d *UserDevice) Capabilities() tio.Capabilities {
+	return tio.Capabilities{}
+}
+
 func (d *UserDevice) Read() ([]tio.Packet, error) {
 	if d.readBuf == nil {
 		d.readBuf = make([]byte, defaultBatchBufSize)