Copy fuzzers from github.com/cncf/cncf-fuzzing

This commit copies the fuzzers from the repository except for
containerd_import_structured_fuzzer.go.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

contrib/fuzz/exchange_fuzzer.go

@@ -0,0 +1,54 @@
+// Copyright 2021 ADA Logics Ltd
+//
+// 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 fuzz
+
+import (
+	"context"
+
+	fuzz "github.com/AdaLogics/go-fuzz-headers"
+	eventstypes "github.com/containerd/containerd/api/events"
+	"github.com/containerd/containerd/events"
+	"github.com/containerd/containerd/events/exchange"
+	"github.com/containerd/containerd/namespaces"
+)
+
+func FuzzExchange(data []byte) int {
+	f := fuzz.NewConsumer(data)
+	namespace, err := f.GetString()
+	if err != nil {
+		return 0
+	}
+	event := &eventstypes.ContainerCreate{}
+	err = f.GenerateStruct(event)
+	if err != nil {
+		return 0
+	}
+	input, err := f.GetString()
+	if err != nil {
+		return 0
+	}
+
+	env := &events.Envelope{}
+	err = f.GenerateStruct(env)
+	if err != nil {
+		return 0
+	}
+	ctx := namespaces.WithNamespace(context.Background(), namespace)
+	exch := exchange.NewExchange()
+	exch.Publish(ctx, input, event)
+	exch.Forward(ctx, env)
+	return 1
+}