Support creating protocol instances with Stack ref

Network or transport protocols may want to reach the stack. Support this
by letting the stack create the protocol instances so it can pass a
reference to itself at protocol creation time.

Note, protocols do not yet use the stack in this CL but later CLs will
make use of the stack from protocols.

PiperOrigin-RevId: 334260210

3 files changed, 14 insertions, 19 deletions

diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index 371067048..6a3c2c32b 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -12,12 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package tcp contains the implementation of the TCP transport protocol. To use
-// it in the networking stack, this package must be added to the project, and
-// activated on the stack by passing tcp.NewProtocol() as one of the
-// transport protocols when calling stack.New(). Then endpoints can be created
-// by passing tcp.ProtocolNumber as the transport protocol number when calling
-// Stack.NewEndpoint().
+// Package tcp contains the implementation of the TCP transport protocol.
 package tcp
 
 import (
@@ -510,7 +505,7 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) bool {
 }
 
 // NewProtocol returns a TCP transport protocol.
-func NewProtocol() stack.TransportProtocol {
+func NewProtocol(*stack.Stack) stack.TransportProtocol {
 	p := protocol{
 		sendBufferSize: tcpip.TCPSendBufferSizeRangeOption{
 			Min:     MinBufferSize,
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go
index 8326736dc..dd810f594 100644
--- a/pkg/tcpip/transport/tcp/tcp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_test.go
@@ -4300,8 +4300,8 @@ func checkSendBufferSize(t *testing.T, ep tcpip.Endpoint, v int) {
 
 func TestDefaultBufferSizes(t *testing.T) {
 	s := stack.New(stack.Options{
-		NetworkProtocols:   []stack.NetworkProtocol{ipv4.NewProtocol()},
-		TransportProtocols: []stack.TransportProtocol{tcp.NewProtocol()},
+		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 	})
 
 	// Check the default values.
@@ -4363,8 +4363,8 @@ func TestDefaultBufferSizes(t *testing.T) {
 
 func TestMinMaxBufferSizes(t *testing.T) {
 	s := stack.New(stack.Options{
-		NetworkProtocols:   []stack.NetworkProtocol{ipv4.NewProtocol()},
-		TransportProtocols: []stack.TransportProtocol{tcp.NewProtocol()},
+		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 	})
 
 	// Check the default values.
@@ -4420,8 +4420,8 @@ func TestMinMaxBufferSizes(t *testing.T) {
 
 func TestBindToDeviceOption(t *testing.T) {
 	s := stack.New(stack.Options{
-		NetworkProtocols:   []stack.NetworkProtocol{ipv4.NewProtocol()},
-		TransportProtocols: []stack.TransportProtocol{tcp.NewProtocol()}})
+		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol}})
 
 	ep, err := s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &waiter.Queue{})
 	if err != nil {
@@ -4470,11 +4470,11 @@ func TestBindToDeviceOption(t *testing.T) {
 
 func makeStack() (*stack.Stack, *tcpip.Error) {
 	s := stack.New(stack.Options{
-		NetworkProtocols: []stack.NetworkProtocol{
-			ipv4.NewProtocol(),
-			ipv6.NewProtocol(),
+		NetworkProtocols: []stack.NetworkProtocolFactory{
+			ipv4.NewProtocol,
+			ipv6.NewProtocol,
 		},
-		TransportProtocols: []stack.TransportProtocol{tcp.NewProtocol()},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 	})
 
 	id := loopback.New()
diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index ebbae6e2f..faf51ef95 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -155,8 +155,8 @@ type Context struct {
 // stack and a link-layer endpoint.
 func New(t *testing.T, mtu uint32) *Context {
 	s := stack.New(stack.Options{
-		NetworkProtocols:   []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol()},
-		TransportProtocols: []stack.TransportProtocol{tcp.NewProtocol()},
+		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
 	})
 
 	const sendBufferSize = 1 << 20 // 1 MiB