config: split and refactor

Introduce generic config.Load function that can be
reused across multiple programs (syz-manager, syz-gce, etc).
Move the generic config functionality to pkg/config package.
The idea is to move all helper (non-main) packages to pkg/ dir,
because we have more and more of them and they pollute the top dir.
Move the syz-manager config parts into syz-manager/config package.

9 files changed, 144 insertions, 90 deletions

diff --git a/config/config_test.go b/config/config_test.go
deleted file mode 100644
index 67bcd5059..000000000
--- a/config/config_test.go
+++ /dev/null
@@ -1,24 +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 (
-	"testing"
-)
-
-func TestUnknown(t *testing.T) {
-	data := `{"foo": "bar"}`
-	_, _, err := parse([]byte(data))
-	if err == nil || err.Error() != "unknown field 'foo' in config" {
-		t.Fatalf("unknown field is not detected (%v)", err)
-	}
-}
-
-func TestReflectUnknown(t *testing.T) {
-	data := `{"http": "localhost:56741","ParsedIgnores": [], "Odroid_Hub_Bus": "bus"}`
-	_, _, err := parse([]byte(data))
-	if err == nil || err.Error() != "unknown field 'ParsedIgnores' in config" {
-		t.Fatalf("unknown field is not detected (%v)", err)
-	}
-}
diff --git a/pkg/config/config.go b/pkg/config/config.go
new file mode 100644
index 000000000..feb031c71
--- /dev/null
+++ b/pkg/config/config.go
@@ -0,0 +1,61 @@
+// Copyright 2017 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"
+	"io/ioutil"
+	"reflect"
+	"strings"
+)
+
+func Load(filename string, cfg interface{}) error {
+	if filename == "" {
+		return fmt.Errorf("no config file specified")
+	}
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return fmt.Errorf("failed to read config file: %v", err)
+	}
+	return load(data, cfg)
+}
+
+func load(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 {
+		return fmt.Errorf("failed to parse config file: %v", err)
+	}
+	return nil
+}
+
+func checkUnknownFields(data []byte, typ reflect.Type) error {
+	if typ.Kind() != reflect.Ptr {
+		return fmt.Errorf("config type is not pointer to struct")
+	}
+	typ = typ.Elem()
+	if typ.Kind() != reflect.Struct {
+		return fmt.Errorf("config type is not pointer to struct")
+	}
+	fields := make(map[string]bool)
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		if field.Tag.Get("json") == "-" {
+			continue
+		}
+		fields[strings.ToLower(field.Name)] = true
+	}
+	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 := range f {
+		if !fields[strings.ToLower(k)] {
+			return fmt.Errorf("unknown field '%v' in config", k)
+		}
+	}
+	return nil
+}
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
new file mode 100644
index 000000000..73ad3502c
--- /dev/null
+++ b/pkg/config/config_test.go
@@ -0,0 +1,65 @@
+// 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 (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestUnknown(t *testing.T) {
+	type Config struct {
+		Foo int
+		Bar string
+		Baz string `json:"-"`
+	}
+	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",
+		},
+	}
+	for i, test := range tests {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			var cfg Config
+			err := load([]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 '%#v', got '%#v'", test.output, cfg)
+			}
+		})
+	}
+}
diff --git a/repro/repro.go b/repro/repro.go
index b9124942e..1d7f39518 100644
--- a/repro/repro.go
+++ b/repro/repro.go
@@ -11,12 +11,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/google/syzkaller/config"
 	"github.com/google/syzkaller/csource"
 	"github.com/google/syzkaller/fileutil"
 	. "github.com/google/syzkaller/log"
 	"github.com/google/syzkaller/prog"
 	"github.com/google/syzkaller/report"
+	"github.com/google/syzkaller/syz-manager/config"
 	"github.com/google/syzkaller/vm"
 )
 
diff --git a/syz-gce/syz-gce.go b/syz-gce/syz-gce.go
index 2e254556c..9bdedbe5b 100644
--- a/syz-gce/syz-gce.go
+++ b/syz-gce/syz-gce.go
@@ -38,10 +38,11 @@ import (
 	"time"
 
 	"cloud.google.com/go/storage"
-	"github.com/google/syzkaller/config"
 	"github.com/google/syzkaller/dashboard"
 	"github.com/google/syzkaller/gce"
 	. "github.com/google/syzkaller/log"
+	pkgconfig "github.com/google/syzkaller/pkg/config"
+	"github.com/google/syzkaller/syz-manager/config"
 	"golang.org/x/net/context"
 )
 
@@ -89,7 +90,12 @@ type Action interface {
 
 func main() {
 	flag.Parse()
-	cfg = readConfig(*flagConfig)
+	cfg = &Config{
+		Use_Dashboard_Patches: true,
+	}
+	if err := pkgconfig.Load(*flagConfig, cfg); err != nil {
+		Fatalf("failed to load config file: %v", err)
+	}
 	EnableLogCaching(1000, 1<<20)
 	initHttp(fmt.Sprintf(":%v", cfg.Http_Port))
 
@@ -493,22 +499,6 @@ func (a *GCSImageAction) Build() error {
 	return nil
 }
 
-func readConfig(filename string) *Config {
-	if filename == "" {
-		Fatalf("supply config in -config flag")
-	}
-	data, err := ioutil.ReadFile(filename)
-	if err != nil {
-		Fatalf("failed to read config file: %v", err)
-	}
-	cfg := new(Config)
-	cfg.Use_Dashboard_Patches = true
-	if err := json.Unmarshal(data, cfg); err != nil {
-		Fatalf("failed to parse config file: %v", err)
-	}
-	return cfg
-}
-
 func writeManagerConfig(cfg *Config, httpPort int, file string) error {
 	tag, err := ioutil.ReadFile("image/tag")
 	if err != nil {
diff --git a/config/config.go b/syz-manager/config/config.go
index 99314249b..12db5696d 100644
--- a/config/config.go
+++ b/syz-manager/config/config.go
@@ -4,16 +4,14 @@
 package config
 
 import (
-	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
-	"reflect"
 	"regexp"
 	"strings"
 
 	"github.com/google/syzkaller/fileutil"
+	pkgconfig "github.com/google/syzkaller/pkg/config"
 	"github.com/google/syzkaller/sys"
 	"github.com/google/syzkaller/vm"
 )
@@ -79,28 +77,14 @@ type Config struct {
 }
 
 func Parse(filename string) (*Config, map[int]bool, error) {
-	if filename == "" {
-		return nil, nil, fmt.Errorf("supply config in -config flag")
+	cfg := &Config{
+		Cover:     true,
+		Reproduce: true,
+		Sandbox:   "setuid",
 	}
-	data, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed to read config file: %v", err)
-	}
-	return parse(data)
-}
-
-func parse(data []byte) (*Config, map[int]bool, error) {
-	err := checkUnknownFields(data)
-	if err != nil {
+	if err := pkgconfig.Load(filename, cfg); err != nil {
 		return nil, nil, err
 	}
-	cfg := new(Config)
-	cfg.Cover = true
-	cfg.Reproduce = true
-	cfg.Sandbox = "setuid"
-	if err := json.Unmarshal(data, cfg); err != nil {
-		return nil, nil, fmt.Errorf("failed to parse config file: %v", err)
-	}
 	if _, err := os.Stat(filepath.Join(cfg.Syzkaller, "bin/syz-fuzzer")); err != nil {
 		return nil, nil, fmt.Errorf("bad config syzkaller param: can't find bin/syz-fuzzer")
 	}
@@ -362,25 +346,3 @@ func CreateVMConfig(cfg *Config, index int) (*vm.Config, error) {
 	}
 	return vmCfg, nil
 }
-
-func checkUnknownFields(data []byte) error {
-	structType := reflect.ValueOf(Config{}).Type()
-	fields := make(map[string]bool)
-	for i := 0; i < structType.NumField(); i++ {
-		field := structType.Field(i)
-		if field.Tag.Get("json") == "-" {
-			continue
-		}
-		fields[strings.ToLower(field.Name)] = true
-	}
-	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 := range f {
-		if !fields[strings.ToLower(k)] {
-			return fmt.Errorf("unknown field '%v' in config", k)
-		}
-	}
-	return nil
-}
diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index ad24f4c39..0cdfa320d 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -19,7 +19,6 @@ import (
 	"syscall"
 	"time"
 
-	"github.com/google/syzkaller/config"
 	"github.com/google/syzkaller/cover"
 	"github.com/google/syzkaller/csource"
 	"github.com/google/syzkaller/dashboard"
@@ -30,6 +29,7 @@ import (
 	"github.com/google/syzkaller/report"
 	"github.com/google/syzkaller/repro"
 	. "github.com/google/syzkaller/rpctype"
+	"github.com/google/syzkaller/syz-manager/config"
 	"github.com/google/syzkaller/vm"
 	_ "github.com/google/syzkaller/vm/adb"
 	_ "github.com/google/syzkaller/vm/gce"
diff --git a/tools/syz-crush/crush.go b/tools/syz-crush/crush.go
index d519107f9..f1796baf0 100644
--- a/tools/syz-crush/crush.go
+++ b/tools/syz-crush/crush.go
@@ -18,8 +18,8 @@ import (
 	"syscall"
 	"time"
 
-	"github.com/google/syzkaller/config"
 	. "github.com/google/syzkaller/log"
+	"github.com/google/syzkaller/syz-manager/config"
 	"github.com/google/syzkaller/vm"
 	_ "github.com/google/syzkaller/vm/adb"
 	_ "github.com/google/syzkaller/vm/gce"
diff --git a/tools/syz-repro/repro.go b/tools/syz-repro/repro.go
index 841a121d1..064846991 100644
--- a/tools/syz-repro/repro.go
+++ b/tools/syz-repro/repro.go
@@ -11,10 +11,10 @@ import (
 	"os/signal"
 	"syscall"
 
-	"github.com/google/syzkaller/config"
 	"github.com/google/syzkaller/csource"
 	. "github.com/google/syzkaller/log"
 	"github.com/google/syzkaller/repro"
+	"github.com/google/syzkaller/syz-manager/config"
 	"github.com/google/syzkaller/vm"
 	_ "github.com/google/syzkaller/vm/adb"
 	_ "github.com/google/syzkaller/vm/gce"