Change tcpip.Error to an interface

This makes it possible to add data to types that implement tcpip.Error.
ErrBadLinkEndpoint is removed as it is unused.

PiperOrigin-RevId: 354437314

2 files changed, 4 insertions, 4 deletions

diff --git a/pkg/tcpip/link/waitable/waitable.go b/pkg/tcpip/link/waitable/waitable.go
index 30f1ad540..20259b285 100644
--- a/pkg/tcpip/link/waitable/waitable.go
+++ b/pkg/tcpip/link/waitable/waitable.go
@@ -108,7 +108,7 @@ 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.RouteInfo, gso *stack.GSO, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) *tcpip.Error {
+func (e *Endpoint) WritePacket(r stack.RouteInfo, gso *stack.GSO, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) tcpip.Error {
 	if !e.writeGate.Enter() {
 		return nil
 	}
@@ -121,7 +121,7 @@ func (e *Endpoint) WritePacket(r stack.RouteInfo, gso *stack.GSO, protocol tcpip
 // WritePackets implements stack.LinkEndpoint.WritePackets. 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) WritePackets(r stack.RouteInfo, gso *stack.GSO, pkts stack.PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, *tcpip.Error) {
+func (e *Endpoint) WritePackets(r stack.RouteInfo, gso *stack.GSO, pkts stack.PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
 	if !e.writeGate.Enter() {
 		return pkts.Len(), nil
 	}
diff --git a/pkg/tcpip/link/waitable/waitable_test.go b/pkg/tcpip/link/waitable/waitable_test.go
index b139de7dd..e368a9eaa 100644
--- a/pkg/tcpip/link/waitable/waitable_test.go
+++ b/pkg/tcpip/link/waitable/waitable_test.go
@@ -69,13 +69,13 @@ func (e *countedEndpoint) LinkAddress() tcpip.LinkAddress {
 	return e.linkAddr
 }
 
-func (e *countedEndpoint) WritePacket(stack.RouteInfo, *stack.GSO, tcpip.NetworkProtocolNumber, *stack.PacketBuffer) *tcpip.Error {
+func (e *countedEndpoint) WritePacket(stack.RouteInfo, *stack.GSO, tcpip.NetworkProtocolNumber, *stack.PacketBuffer) tcpip.Error {
 	e.writeCount++
 	return nil
 }
 
 // WritePackets implements stack.LinkEndpoint.WritePackets.
-func (e *countedEndpoint) WritePackets(_ stack.RouteInfo, _ *stack.GSO, pkts stack.PacketBufferList, _ tcpip.NetworkProtocolNumber) (int, *tcpip.Error) {
+func (e *countedEndpoint) WritePackets(_ stack.RouteInfo, _ *stack.GSO, pkts stack.PacketBufferList, _ tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
 	e.writeCount += pkts.Len()
 	return pkts.Len(), nil
 }