Pass buffer.Prependable by value

PiperOrigin-RevId: 213053370
Change-Id: I60ea89572b4fca53fd126c870fcbde74fcf52562

9 files changed, 22 insertions, 22 deletions

diff --git a/pkg/tcpip/link/channel/channel.go b/pkg/tcpip/link/channel/channel.go
index a927a1b3f..8b680de7c 100644
--- a/pkg/tcpip/link/channel/channel.go
+++ b/pkg/tcpip/link/channel/channel.go
@@ -109,7 +109,7 @@ func (e *Endpoint) LinkAddress() tcpip.LinkAddress {
 }
 
 // WritePacket stores outbound packets into the channel.
-func (e *Endpoint) WritePacket(_ *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *Endpoint) WritePacket(_ *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	p := PacketInfo{
 		Header:  hdr.View(),
 		Proto:   protocol,
diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go
index 0b985928b..0b0d6c1e2 100644
--- a/pkg/tcpip/link/fdbased/endpoint.go
+++ b/pkg/tcpip/link/fdbased/endpoint.go
@@ -158,7 +158,7 @@ func (e *endpoint) LinkAddress() tcpip.LinkAddress {
 
 // WritePacket writes outbound packets to the file descriptor. If it is not
 // currently writable, the packet is dropped.
-func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	if e.handleLocal && r.LocalAddress != "" && r.LocalAddress == r.RemoteAddress {
 		views := make([]buffer.View, 1, 1+len(payload.Views()))
 		views[0] = hdr.View()
diff --git a/pkg/tcpip/link/fdbased/endpoint_test.go b/pkg/tcpip/link/fdbased/endpoint_test.go
index 21d2f10b0..f7890e031 100644
--- a/pkg/tcpip/link/fdbased/endpoint_test.go
+++ b/pkg/tcpip/link/fdbased/endpoint_test.go
@@ -158,7 +158,7 @@ func TestWritePacket(t *testing.T) {
 					payload[i] = uint8(rand.Intn(256))
 				}
 				want := append(hdr.UsedBytes(), payload...)
-				if err := c.ep.WritePacket(r, &hdr, payload.ToVectorisedView(), proto); err != nil {
+				if err := c.ep.WritePacket(r, hdr, payload.ToVectorisedView(), proto); err != nil {
 					t.Fatalf("WritePacket failed: %v", err)
 				}
 
diff --git a/pkg/tcpip/link/loopback/loopback.go b/pkg/tcpip/link/loopback/loopback.go
index 884de83c9..554ad64de 100644
--- a/pkg/tcpip/link/loopback/loopback.go
+++ b/pkg/tcpip/link/loopback/loopback.go
@@ -72,7 +72,7 @@ func (*endpoint) LinkAddress() tcpip.LinkAddress {
 
 // WritePacket implements stack.LinkEndpoint.WritePacket. It delivers outbound
 // packets to the network-layer dispatcher.
-func (e *endpoint) WritePacket(_ *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *endpoint) WritePacket(_ *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	views := make([]buffer.View, 1, 1+len(payload.Views()))
 	views[0] = hdr.View()
 	views = append(views, payload.Views()...)
diff --git a/pkg/tcpip/link/sharedmem/sharedmem.go b/pkg/tcpip/link/sharedmem/sharedmem.go
index 0dd23794b..887612957 100644
--- a/pkg/tcpip/link/sharedmem/sharedmem.go
+++ b/pkg/tcpip/link/sharedmem/sharedmem.go
@@ -184,7 +184,7 @@ func (e *endpoint) LinkAddress() tcpip.LinkAddress {
 
 // WritePacket writes outbound packets to the file descriptor. If it is not
 // currently writable, the packet is dropped.
-func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	// Add the ethernet header here.
 	eth := header.Ethernet(hdr.Prepend(header.EthernetMinimumSize))
 	eth.Encode(&header.EthernetFields{
diff --git a/pkg/tcpip/link/sharedmem/sharedmem_test.go b/pkg/tcpip/link/sharedmem/sharedmem_test.go
index 682c38400..9a0348deb 100644
--- a/pkg/tcpip/link/sharedmem/sharedmem_test.go
+++ b/pkg/tcpip/link/sharedmem/sharedmem_test.go
@@ -270,7 +270,7 @@ func TestSimpleSend(t *testing.T) {
 		randomFill(buf)
 
 		proto := tcpip.NetworkProtocolNumber(rand.Intn(0x10000))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), proto); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), proto); err != nil {
 			t.Fatalf("WritePacket failed: %v", err)
 		}
 
@@ -336,7 +336,7 @@ func TestFillTxQueue(t *testing.T) {
 	for i := queuePipeSize / 40; i > 0; i-- {
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
 
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 
@@ -351,7 +351,7 @@ func TestFillTxQueue(t *testing.T) {
 
 	// Next attempt to write must fail.
 	hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != want {
+	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != want {
 		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
 	}
 }
@@ -376,7 +376,7 @@ func TestFillTxQueueAfterBadCompletion(t *testing.T) {
 	// Send two packets so that the id slice has at least two slots.
 	for i := 2; i > 0; i-- {
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 	}
@@ -396,7 +396,7 @@ func TestFillTxQueueAfterBadCompletion(t *testing.T) {
 	ids := make(map[uint64]struct{})
 	for i := queuePipeSize / 40; i > 0; i-- {
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 
@@ -411,7 +411,7 @@ func TestFillTxQueueAfterBadCompletion(t *testing.T) {
 
 	// Next attempt to write must fail.
 	hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != want {
+	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != want {
 		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
 	}
 }
@@ -434,7 +434,7 @@ func TestFillTxMemory(t *testing.T) {
 	ids := make(map[uint64]struct{})
 	for i := queueDataSize / bufferSize; i > 0; i-- {
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 
@@ -450,7 +450,7 @@ func TestFillTxMemory(t *testing.T) {
 
 	// Next attempt to write must fail.
 	hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-	err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber)
+	err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber)
 	if want := tcpip.ErrWouldBlock; err != want {
 		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
 	}
@@ -475,7 +475,7 @@ func TestFillTxMemoryWithMultiBuffer(t *testing.T) {
 	// until there is only one buffer left.
 	for i := queueDataSize/bufferSize - 1; i > 0; i-- {
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 
@@ -488,7 +488,7 @@ func TestFillTxMemoryWithMultiBuffer(t *testing.T) {
 	{
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
 		uu := buffer.NewView(bufferSize).ToVectorisedView()
-		if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, &hdr, uu, header.IPv4ProtocolNumber); err != want {
+		if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(&r, hdr, uu, header.IPv4ProtocolNumber); err != want {
 			t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
 		}
 	}
@@ -496,7 +496,7 @@ func TestFillTxMemoryWithMultiBuffer(t *testing.T) {
 	// Attempt to write the one-buffer packet again. It must succeed.
 	{
 		hdr := buffer.NewPrependable(int(c.ep.MaxHeaderLength()))
-		if err := c.ep.WritePacket(&r, &hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
+		if err := c.ep.WritePacket(&r, hdr, buf.ToVectorisedView(), header.IPv4ProtocolNumber); err != nil {
 			t.Fatalf("WritePacket failed unexpectedly: %v", err)
 		}
 	}
diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go
index 5a70e062f..e6ce3ee13 100644
--- a/pkg/tcpip/link/sniffer/sniffer.go
+++ b/pkg/tcpip/link/sniffer/sniffer.go
@@ -188,7 +188,7 @@ func (e *endpoint) LinkAddress() tcpip.LinkAddress {
 // WritePacket implements the stack.LinkEndpoint interface. It is called by
 // higher-level protocols to write packets; it just logs the packet and forwards
 // the request to the lower endpoint.
-func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	if atomic.LoadUint32(&LogPackets) == 1 && e.file == nil {
 		logPacket("send", protocol, hdr.UsedBytes())
 	}
diff --git a/pkg/tcpip/link/waitable/waitable.go b/pkg/tcpip/link/waitable/waitable.go
index cc1717ac7..9b69f844e 100644
--- a/pkg/tcpip/link/waitable/waitable.go
+++ b/pkg/tcpip/link/waitable/waitable.go
@@ -100,7 +100,7 @@ func (e *Endpoint) LinkAddress() tcpip.LinkAddress {
 // WritePacket implements stack.LinkEndpoint.WritePacket. It is called by
 // higher-level protocols to write packets. It only forwards packets to the
 // lower endpoint if Wait or WaitWrite haven't been called.
-func (e *Endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *Endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	if !e.writeGate.Enter() {
 		return nil
 	}
diff --git a/pkg/tcpip/link/waitable/waitable_test.go b/pkg/tcpip/link/waitable/waitable_test.go
index f20ee2fcb..1301cd4b2 100644
--- a/pkg/tcpip/link/waitable/waitable_test.go
+++ b/pkg/tcpip/link/waitable/waitable_test.go
@@ -65,7 +65,7 @@ func (e *countedEndpoint) LinkAddress() tcpip.LinkAddress {
 	return e.linkAddr
 }
 
-func (e *countedEndpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
+func (e *countedEndpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
 	e.writeCount++
 	return nil
 }
@@ -75,21 +75,21 @@ func TestWaitWrite(t *testing.T) {
 	_, wep := New(stack.RegisterLinkEndpoint(ep))
 
 	// Write and check that it goes through.
-	wep.WritePacket(nil, nil, buffer.VectorisedView{}, 0)
+	wep.WritePacket(nil, buffer.Prependable{}, buffer.VectorisedView{}, 0)
 	if want := 1; ep.writeCount != want {
 		t.Fatalf("Unexpected writeCount: got=%v, want=%v", ep.writeCount, want)
 	}
 
 	// Wait on dispatches, then try to write. It must go through.
 	wep.WaitDispatch()
-	wep.WritePacket(nil, nil, buffer.VectorisedView{}, 0)
+	wep.WritePacket(nil, buffer.Prependable{}, buffer.VectorisedView{}, 0)
 	if want := 2; ep.writeCount != want {
 		t.Fatalf("Unexpected writeCount: got=%v, want=%v", ep.writeCount, want)
 	}
 
 	// Wait on writes, then try to write. It must not go through.
 	wep.WaitWrite()
-	wep.WritePacket(nil, nil, buffer.VectorisedView{}, 0)
+	wep.WritePacket(nil, buffer.Prependable{}, buffer.VectorisedView{}, 0)
 	if want := 2; ep.writeCount != want {
 		t.Fatalf("Unexpected writeCount: got=%v, want=%v", ep.writeCount, want)
 	}