Improve the strict configuration validation (#3809)

pkg/config/load.go

@@ -110,8 +110,11 @@ func LoadConfigureFromFile(path string, c any, strict bool) error {
 
 // LoadConfigure loads configuration from bytes and unmarshal into c.
 // Now it supports json, yaml and toml format.
-// TODO(fatedier): strict is not valide for ProxyConfigurer/VisitorConfigurer/ClientPluginOptions.
 func LoadConfigure(b []byte, c any, strict bool) error {
+	v1.DisallowUnknownFieldsMu.Lock()
+	defer v1.DisallowUnknownFieldsMu.Unlock()
+	v1.DisallowUnknownFields = strict
+
 	var tomlObj interface{}
 	// Try to unmarshal as TOML first; swallow errors from that (assume it's not valid TOML).
 	if err := toml.Unmarshal(b, &tomlObj); err == nil {

pkg/config/load_test.go

@@ -111,3 +111,56 @@ func TestLoadServerConfigStrictMode(t *testing.T) {
 		}
 	}
 }
+
+func TestCustomStructStrictMode(t *testing.T) {
+	require := require.New(t)
+
+	proxyStr := `
+serverPort = 7000
+
+[[proxies]]
+name = "test"
+type = "tcp"
+remotePort = 6000
+`
+	clientCfg := v1.ClientConfig{}
+	err := LoadConfigure([]byte(proxyStr), &clientCfg, true)
+	require.NoError(err)
+
+	proxyStr += `unknown = "unknown"`
+	err = LoadConfigure([]byte(proxyStr), &clientCfg, true)
+	require.Error(err)
+
+	visitorStr := `
+serverPort = 7000
+
+[[visitors]]
+name = "test"
+type = "stcp"
+bindPort = 6000
+serverName = "server"
+`
+	err = LoadConfigure([]byte(visitorStr), &clientCfg, true)
+	require.NoError(err)
+
+	visitorStr += `unknown = "unknown"`
+	err = LoadConfigure([]byte(visitorStr), &clientCfg, true)
+	require.Error(err)
+
+	pluginStr := `
+serverPort = 7000
+
+[[proxies]]
+name = "test"
+type = "tcp"
+remotePort = 6000
+[proxies.plugin]
+type = "unix_domain_socket"
+unixPath = "/tmp/uds.sock"
+`
+	err = LoadConfigure([]byte(pluginStr), &clientCfg, true)
+	require.NoError(err)
+	pluginStr += `unknown = "unknown"`
+	err = LoadConfigure([]byte(pluginStr), &clientCfg, true)
+	require.Error(err)
+}

pkg/config/v1/common.go

@@ -15,9 +15,23 @@
 package v1
 
 import (
+	"sync"
+
 	"github.com/fatedier/frp/pkg/util/util"
 )
 
+// TODO(fatedier): Due to the current implementation issue of the go json library, the UnmarshalJSON method
+// of a custom struct cannot access the DisallowUnknownFields parameter of the parent decoder.
+// Here, a global variable is temporarily used to control whether unknown fields are allowed.
+// Once the v2 version is implemented by the community, we can switch to a standardized approach.
+//
+// https://github.com/golang/go/issues/41144
+// https://github.com/golang/go/discussions/63397
+var (
+	DisallowUnknownFields   = false
+	DisallowUnknownFieldsMu sync.Mutex
+)
+
 type AuthScope string
 
 const (

pkg/config/v1/plugin.go

@@ -15,6 +15,7 @@
 package v1
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"reflect"
@@ -49,7 +50,13 @@ func (c *TypedClientPluginOptions) UnmarshalJSON(b []byte) error {
 		return fmt.Errorf("unknown plugin type: %s", typeStruct.Type)
 	}
 	options := reflect.New(v).Interface().(ClientPluginOptions)
-	if err := json.Unmarshal(b, options); err != nil {
+
+	decoder := json.NewDecoder(bytes.NewBuffer(b))
+	if DisallowUnknownFields {
+		decoder.DisallowUnknownFields()
+	}
+
+	if err := decoder.Decode(options); err != nil {
 		return err
 	}
 	c.ClientPluginOptions = options
@@ -77,17 +84,20 @@ var clientPluginOptionsTypeMap = map[string]reflect.Type{
 }
 
 type HTTP2HTTPSPluginOptions struct {
+	Type              string           `json:"type,omitempty"`
 	LocalAddr         string           `json:"localAddr,omitempty"`
 	HostHeaderRewrite string           `json:"hostHeaderRewrite,omitempty"`
 	RequestHeaders    HeaderOperations `json:"requestHeaders,omitempty"`
 }
 
 type HTTPProxyPluginOptions struct {
+	Type         string `json:"type,omitempty"`
 	HTTPUser     string `json:"httpUser,omitempty"`
 	HTTPPassword string `json:"httpPassword,omitempty"`
 }
 
 type HTTPS2HTTPPluginOptions struct {
+	Type              string           `json:"type,omitempty"`
 	LocalAddr         string           `json:"localAddr,omitempty"`
 	HostHeaderRewrite string           `json:"hostHeaderRewrite,omitempty"`
 	RequestHeaders    HeaderOperations `json:"requestHeaders,omitempty"`
@@ -96,6 +106,7 @@ type HTTPS2HTTPPluginOptions struct {
 }
 
 type HTTPS2HTTPSPluginOptions struct {
+	Type              string           `json:"type,omitempty"`
 	LocalAddr         string           `json:"localAddr,omitempty"`
 	HostHeaderRewrite string           `json:"hostHeaderRewrite,omitempty"`
 	RequestHeaders    HeaderOperations `json:"requestHeaders,omitempty"`
@@ -104,11 +115,13 @@ type HTTPS2HTTPSPluginOptions struct {
 }
 
 type Socks5PluginOptions struct {
+	Type     string `json:"type,omitempty"`
 	Username string `json:"username,omitempty"`
 	Password string `json:"password,omitempty"`
 }
 
 type StaticFilePluginOptions struct {
+	Type         string `json:"type,omitempty"`
 	LocalPath    string `json:"localPath,omitempty"`
 	StripPrefix  string `json:"stripPrefix,omitempty"`
 	HTTPUser     string `json:"httpUser,omitempty"`
@@ -116,5 +129,6 @@ type StaticFilePluginOptions struct {
 }
 
 type UnixDomainSocketPluginOptions struct {
+	Type     string `json:"type,omitempty"`
 	UnixPath string `json:"unixPath,omitempty"`
 }

pkg/config/v1/proxy.go

@@ -15,6 +15,7 @@
 package v1
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -177,7 +178,11 @@ func (c *TypedProxyConfig) UnmarshalJSON(b []byte) error {
 	if configurer == nil {
 		return fmt.Errorf("unknown proxy type: %s", typeStruct.Type)
 	}
-	if err := json.Unmarshal(b, configurer); err != nil {
+	decoder := json.NewDecoder(bytes.NewBuffer(b))
+	if DisallowUnknownFields {
+		decoder.DisallowUnknownFields()
+	}
+	if err := decoder.Decode(configurer); err != nil {
 		return err
 	}
 	c.ProxyConfigurer = configurer

pkg/config/v1/visitor.go

@@ -15,6 +15,7 @@
 package v1
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -108,7 +109,11 @@ func (c *TypedVisitorConfig) UnmarshalJSON(b []byte) error {
 	if configurer == nil {
 		return fmt.Errorf("unknown visitor type: %s", typeStruct.Type)
 	}
-	if err := json.Unmarshal(b, configurer); err != nil {
+	decoder := json.NewDecoder(bytes.NewBuffer(b))
+	if DisallowUnknownFields {
+		decoder.DisallowUnknownFields()
+	}
+	if err := decoder.Decode(configurer); err != nil {
 		return err
 	}
 	c.VisitorConfigurer = configurer
@@ -120,7 +125,9 @@ func NewVisitorConfigurerByType(t VisitorType) VisitorConfigurer {
 	if !ok {
 		return nil
 	}
-	return reflect.New(v).Interface().(VisitorConfigurer)
+	vc := reflect.New(v).Interface().(VisitorConfigurer)
+	vc.GetBaseConfig().Type = string(t)
+	return vc
 }
 
 var _ VisitorConfigurer = &STCPVisitorConfig{}