1 files changed, 45 insertions, 0 deletions
diff --git a/pkg/sentry/unimpl/events.go b/pkg/sentry/unimpl/events.go
new file mode 100644
index 000000000..f78f8c981
--- /dev/null
+++ b/pkg/sentry/unimpl/events.go
@@ -0,0 +1,45 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package unimpl contains interface to emit events about unimplemented
+// features.
+package unimpl
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/log"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+)
+
+// contextID is the events package's type for context.Context.Value keys.
+type contextID int
+
+const (
+	// CtxEvents is a Context.Value key for a Events.
+	CtxEvents contextID = iota
+)
+
+// Events interface defines method to emit unsupported events.
+type Events interface {
+	EmitUnimplementedEvent(context.Context)
+}
+
+// EmitUnimplementedEvent emits unsupported syscall event to the context.
+func EmitUnimplementedEvent(ctx context.Context) {
+	e := ctx.Value(CtxEvents)
+	if e == nil {
+		log.Warningf("Context.Value(CtxEvents) not present, unimplemented syscall event not reported.")
+		return
+	}
+	e.(Events).EmitUnimplementedEvent(ctx)
+}