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>

remotes/docker/config/docker_fuzzer_internal.go

@@ -0,0 +1,46 @@
+//go:build gofuzz
+// +build gofuzz
+
+/*
+   Copyright The containerd Authors.
+
+   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 config
+
+import (
+	"io/ioutil"
+	"os"
+
+	fuzz "github.com/AdaLogics/go-fuzz-headers"
+)
+
+func FuzzParseHostsFile(data []byte) int {
+	f := fuzz.NewConsumer(data)
+	dir, err := ioutil.TempDir("", "fuzz-")
+	if err != nil {
+		return 0
+	}
+	err = f.CreateFiles(dir)
+	if err != nil {
+		return 0
+	}
+	defer os.RemoveAll(dir)
+	b, err := f.GetBytes()
+	if err != nil {
+		return 0
+	}
+	_, _ = parseHostsFile(dir, b)
+	return 1
+}