pkg/config: use DisallowUnknownFields

DisallowUnknownFields was added in Go 1.10,
remove our custom machinery for checking unknown fields.

2 files changed, 4 insertions, 290 deletions

diff --git a/pkg/config/config.go b/pkg/config/config.go
index 49d030499..a4f56c225 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -4,11 +4,10 @@
 package config
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"reflect"
-	"strings"
 
 	"github.com/google/syzkaller/pkg/osutil"
 )
@@ -25,10 +24,9 @@ func LoadFile(filename string, cfg interface{}) error {
 }
 
 func LoadData(data []byte, cfg interface{}) error {
-	if err := checkUnknownFields(data, reflect.ValueOf(cfg).Type()); err != nil {
-		return err
-	}
-	if err := json.Unmarshal(data, cfg); err != nil {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(cfg); err != nil {
 		return fmt.Errorf("failed to parse config file: %v", err)
 	}
 	return nil
@@ -45,81 +43,3 @@ func SaveFile(filename string, cfg interface{}) error {
 func SaveData(cfg interface{}) ([]byte, error) {
 	return json.MarshalIndent(cfg, "", "\t")
 }
-
-func checkUnknownFields(data []byte, typ reflect.Type) error {
-	if typ.Kind() != reflect.Ptr || typ.Elem().Kind() != reflect.Struct {
-		return fmt.Errorf("config type is not pointer to struct")
-	}
-	return checkUnknownFieldsRec(data, "", typ)
-}
-
-func checkUnknownFieldsRec(data []byte, prefix string, typ reflect.Type) error {
-	if typ.Kind() == reflect.Ptr {
-		typ = typ.Elem()
-	}
-	if typ.Kind() != reflect.Struct {
-		return fmt.Errorf("config type is not pointer to struct")
-	}
-	fields := make(map[string]reflect.Type)
-	for i := 0; i < typ.NumField(); i++ {
-		field := typ.Field(i)
-		tag := field.Tag.Get("json")
-		tag = strings.TrimSuffix(tag, ",omitempty")
-		if tag == "-" {
-			continue
-		}
-		name := strings.ToLower(field.Name)
-		if tag != "" {
-			if tag != strings.ToLower(tag) {
-				return fmt.Errorf("json tag on '%v%v' should be lower-case", prefix, name)
-			}
-			name = tag
-		}
-		fields[name] = field.Type
-	}
-	f := make(map[string]interface{})
-	if err := json.Unmarshal(data, &f); err != nil {
-		return fmt.Errorf("failed to parse config file: %v", err)
-	}
-	for k, v := range f {
-		field, ok := fields[strings.ToLower(k)]
-		if !ok {
-			return fmt.Errorf("unknown field '%v%v' in config", prefix, k)
-		}
-		if v != nil && field.Kind() == reflect.Slice &&
-			(field.PkgPath() != "encoding/json" || field.Name() != "RawMessage") {
-			vv := reflect.ValueOf(v)
-			if vv.Type().Kind() != reflect.Slice {
-				return fmt.Errorf("bad json array type '%v%v'", prefix, k)
-			}
-			for i := 0; i < vv.Len(); i++ {
-				e := vv.Index(i).Interface()
-				prefix1 := fmt.Sprintf("%v%v[%v].", prefix, k, i)
-				if err := checkUnknownFieldsStruct(e, prefix1, field.Elem()); err != nil {
-					return err
-				}
-			}
-		}
-		if err := checkUnknownFieldsStruct(v, prefix+k+".", field); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func checkUnknownFieldsStruct(val interface{}, prefix string, typ reflect.Type) error {
-	if typ.Kind() == reflect.Ptr {
-		typ = typ.Elem()
-	}
-	if typ.Kind() != reflect.Struct {
-		return nil
-	}
-	if typ.PkgPath() == "time" && typ.Name() == "Time" {
-		return nil
-	}
-	inner, err := json.Marshal(val)
-	if err != nil {
-		return fmt.Errorf("failed to marshal inner struct %q: %v", prefix, err)
-	}
-	return checkUnknownFieldsRec(inner, prefix, typ)
-}
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
deleted file mode 100644
index c8cd3e6ed..000000000
--- a/pkg/config/config_test.go
+++ /dev/null
@@ -1,206 +0,0 @@
-// Copyright 2016 syzkaller project authors. All rights reserved.
-// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
-
-package config
-
-import (
-	"encoding/json"
-	"fmt"
-	"reflect"
-	"testing"
-	"time"
-)
-
-func TestLoad(t *testing.T) {
-	type NestedNested struct {
-		Ccc int
-		Ddd string
-	}
-	type Nested struct {
-		Aaa  int
-		Bbb  string
-		More NestedNested
-	}
-	type Config struct {
-		Foo int
-		Bar string
-		Baz string `json:"-"`
-		Raw json.RawMessage
-		Qux []string
-		Box Nested
-		Boq *Nested
-		Arr []Nested
-		T   time.Time
-	}
-
-	tests := []struct {
-		input  string
-		output Config
-		err    string
-	}{
-		{
-			`{"foo": 42}`,
-			Config{
-				Foo: 42,
-			},
-			"",
-		},
-		{
-			`{"BAR": "Baz", "foo": 42}`,
-			Config{
-				Foo: 42,
-				Bar: "Baz",
-			},
-			"",
-		},
-		{
-			`{"foobar": 42}`,
-			Config{},
-			"unknown field 'foobar' in config",
-		},
-		{
-			`{"foo": 1, "baz": "baz", "bar": "bar"}`,
-			Config{},
-			"unknown field 'baz' in config",
-		},
-		{
-			`{"foo": 1, "box": {"aaa": 12, "bbb": "bbb"}}`,
-			Config{
-				Foo: 1,
-				Box: Nested{
-					Aaa: 12,
-					Bbb: "bbb",
-				},
-			},
-			"",
-		},
-		{
-			`{"qux": ["aaa", "bbb"]}`,
-			Config{
-				Qux: []string{"aaa", "bbb"},
-			},
-			"",
-		},
-		{
-			`{"box": {"aaa": 12, "ccc": "bbb"}}`,
-			Config{},
-			"unknown field 'box.ccc' in config",
-		},
-		{
-			`{"foo": 1, "boq": {"aaa": 12, "bbb": "bbb"}}`,
-			Config{
-				Foo: 1,
-				Boq: &Nested{
-					Aaa: 12,
-					Bbb: "bbb",
-				},
-			},
-			"",
-		},
-		{
-			`{"boq": {"aaa": 12, "ccc": "bbb"}}`,
-			Config{},
-			"unknown field 'boq.ccc' in config",
-		},
-
-		{
-			`{"foo": 1, "arr": []}`,
-			Config{
-				Foo: 1,
-				Arr: []Nested{},
-			},
-			"",
-		},
-		{
-			`{"foo": 1, "arr": [{"aaa": 12, "bbb": "bbb"}, {"aaa": 13, "bbb": "ccc"}]}`,
-			Config{
-				Foo: 1,
-				Arr: []Nested{
-					{
-						Aaa: 12,
-						Bbb: "bbb",
-					},
-					{
-						Aaa: 13,
-						Bbb: "ccc",
-					},
-				},
-			},
-			"",
-		},
-		{
-			`{"arr": [{"aaa": 12, "ccc": "bbb"}]}`,
-			Config{},
-			"unknown field 'arr[0].ccc' in config",
-		},
-		{
-			`{"foo": 1, "boq": {"aaa": 12, "more": {"ccc": 13, "ddd": "ddd"}}}`,
-			Config{
-				Foo: 1,
-				Boq: &Nested{
-					Aaa: 12,
-					More: NestedNested{
-						Ccc: 13,
-						Ddd: "ddd",
-					},
-				},
-			},
-			"",
-		},
-		{
-			`{"foo": 1, "boq": {"aaa": 12, "more": {"ccc": 13, "eee": "eee"}}}`,
-			Config{},
-			"unknown field 'boq.more.eee' in config",
-		},
-		{
-			`{"raw": {"zux": 11}}`,
-			Config{
-				Raw: []byte(`{"zux": 11}`),
-			},
-			"",
-		},
-		{
-			`{"foo": null, "qux": null}`,
-			Config{},
-			"",
-		},
-		{
-			`{"t": "2000-01-02T03:04:05Z"}`,
-			Config{
-				T: time.Date(2000, 1, 2, 3, 4, 5, 0, time.UTC),
-			},
-			"",
-		},
-	}
-	for i, test := range tests {
-		t.Run(fmt.Sprint(i), func(t *testing.T) {
-			var cfg Config
-			err := LoadData([]byte(test.input), &cfg)
-			errStr := ""
-			if err != nil {
-				errStr = err.Error()
-			}
-			if test.err != errStr {
-				t.Fatalf("bad err: want '%v', got '%v'", test.err, errStr)
-			}
-			if !reflect.DeepEqual(test.output, cfg) {
-				t.Fatalf("bad output: want:\n%#v\n, got:\n%#v", test.output, cfg)
-			}
-		})
-	}
-}
-
-func TestLoadBadType(t *testing.T) {
-	want := "config type is not pointer to struct"
-	if err := LoadData([]byte("{}"), 1); err == nil || err.Error() != want {
-		t.Fatalf("got '%v', want '%v'", err, want)
-	}
-	i := 0
-	if err := LoadData([]byte("{}"), &i); err == nil || err.Error() != want {
-		t.Fatalf("got '%v', want '%v'", err, want)
-	}
-	s := struct{}{}
-	if err := LoadData([]byte("{}"), s); err == nil || err.Error() != want {
-		t.Fatalf("got '%v', want '%v'", err, want)
-	}
-}