From 9a8488074ea36561e72af010d85a704796723e24 Mon Sep 17 00:00:00 2001
From: Darien Raymond <admin@v2ray.com>
Date: Wed, 18 Jul 2018 10:40:28 +0200
Subject: [PATCH] env flag controlled global padding

---
 common/platform/platform.go      | 13 ++++++++++---
 proxy/vmess/encoding/auth.go     |  2 +-
 proxy/vmess/inbound/inbound.go   |  5 ++---
 proxy/vmess/outbound/outbound.go | 20 +++++++++++++++++---
 testing/scenarios/vmess_test.go  |  9 +++++++--
 5 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/common/platform/platform.go b/common/platform/platform.go
index 3b86ec9dc..4fa253d9c 100644
--- a/common/platform/platform.go
+++ b/common/platform/platform.go
@@ -12,6 +12,13 @@ type EnvFlag struct {
 	AltName string
 }
 
+func NewEnvFlag(name string) EnvFlag {
+	return EnvFlag{
+		Name:    name,
+		AltName: NormalizeEnvName(name),
+	}
+}
+
 func (f EnvFlag) GetValue(defaultValue func() string) string {
 	if v, found := os.LookupEnv(f.Name); found {
 		return v
@@ -61,18 +68,18 @@ func getExecutableSubDir(dir string) func() string {
 
 func GetAssetLocation(file string) string {
 	const name = "v2ray.location.asset"
-	assetPath := EnvFlag{Name: name, AltName: NormalizeEnvName(name)}.GetValue(getExecutableDir)
+	assetPath := NewEnvFlag(name).GetValue(getExecutableDir)
 	return filepath.Join(assetPath, file)
 }
 
 func GetPluginDirectory() string {
 	const name = "v2ray.location.plugin"
-	pluginDir := EnvFlag{Name: name, AltName: NormalizeEnvName(name)}.GetValue(getExecutableSubDir("plugins"))
+	pluginDir := NewEnvFlag(name).GetValue(getExecutableSubDir("plugins"))
 	return pluginDir
 }
 
 func GetConfigurationPath() string {
 	const name = "v2ray.location.config"
-	configPath := EnvFlag{Name: name, AltName: NormalizeEnvName(name)}.GetValue(getExecutableDir)
+	configPath := NewEnvFlag(name).GetValue(getExecutableDir)
 	return filepath.Join(configPath, "config.json")
 }
diff --git a/proxy/vmess/encoding/auth.go b/proxy/vmess/encoding/auth.go
index 9f0128960..dc668d879 100644
--- a/proxy/vmess/encoding/auth.go
+++ b/proxy/vmess/encoding/auth.go
@@ -112,6 +112,6 @@ func (s *ShakeSizeParser) NextPaddingLen() uint16 {
 	return s.next() % 64
 }
 
-func (s *ShakeSizeParser) MaxPaddingLne() uint16 {
+func (s *ShakeSizeParser) MaxPaddingLen() uint16 {
 	return 64
 }
diff --git a/proxy/vmess/inbound/inbound.go b/proxy/vmess/inbound/inbound.go
index 73be09876..b63c80b83 100644
--- a/proxy/vmess/inbound/inbound.go
+++ b/proxy/vmess/inbound/inbound.go
@@ -9,9 +9,6 @@ import (
 	"sync"
 	"time"
 
-	"v2ray.com/core/common/session"
-	"v2ray.com/core/common/task"
-
 	"v2ray.com/core"
 	"v2ray.com/core/common"
 	"v2ray.com/core/common/buf"
@@ -20,7 +17,9 @@ import (
 	"v2ray.com/core/common/net"
 	"v2ray.com/core/common/protocol"
 	"v2ray.com/core/common/serial"
+	"v2ray.com/core/common/session"
 	"v2ray.com/core/common/signal"
+	"v2ray.com/core/common/task"
 	"v2ray.com/core/common/uuid"
 	"v2ray.com/core/proxy/vmess"
 	"v2ray.com/core/proxy/vmess/encoding"
diff --git a/proxy/vmess/outbound/outbound.go b/proxy/vmess/outbound/outbound.go
index 1f58befcf..65de77fad 100644
--- a/proxy/vmess/outbound/outbound.go
+++ b/proxy/vmess/outbound/outbound.go
@@ -6,16 +6,16 @@ import (
 	"context"
 	"time"
 
-	"v2ray.com/core/common/session"
-	"v2ray.com/core/common/task"
-
 	"v2ray.com/core"
 	"v2ray.com/core/common"
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/net"
+	"v2ray.com/core/common/platform"
 	"v2ray.com/core/common/protocol"
 	"v2ray.com/core/common/retry"
+	"v2ray.com/core/common/session"
 	"v2ray.com/core/common/signal"
+	"v2ray.com/core/common/task"
 	"v2ray.com/core/proxy"
 	"v2ray.com/core/proxy/vmess"
 	"v2ray.com/core/proxy/vmess/encoding"
@@ -87,6 +87,10 @@ func (v *Handler) Process(ctx context.Context, link *core.Link, dialer proxy.Dia
 		Option:  protocol.RequestOptionChunkStream,
 	}
 
+	if enablePadding {
+		request.Option.Set(protocol.RequestOptionGlobalPadding)
+	}
+
 	rawAccount, err := request.User.GetTypedAccount()
 	if err != nil {
 		return newError("failed to get user account").Base(err).AtWarning()
@@ -161,8 +165,18 @@ func (v *Handler) Process(ctx context.Context, link *core.Link, dialer proxy.Dia
 	return nil
 }
 
+var (
+	enablePadding = false
+)
+
 func init() {
 	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
 		return New(ctx, config.(*Config))
 	}))
+
+	const defaultFlagValue = "NOT_DEFINED_AT_ALL"
+	paddingValue := platform.NewEnvFlag("v2ray.vmess.padding").GetValue(func() string { return defaultFlagValue })
+	if paddingValue != defaultFlagValue {
+		enablePadding = true
+	}
 }
diff --git a/testing/scenarios/vmess_test.go b/testing/scenarios/vmess_test.go
index e70a2b675..8a73cec84 100644
--- a/testing/scenarios/vmess_test.go
+++ b/testing/scenarios/vmess_test.go
@@ -253,8 +253,15 @@ func TestVMessGCM(t *testing.T) {
 		},
 	}
 
+	/*
+		const envName = "V2RAY_VMESS_PADDING"
+		common.Must(os.Setenv(envName, "1"))
+		defer os.Unsetenv(envName)
+	*/
+
 	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
 	assert(err, IsNil)
+	defer CloseAllServers(servers)
 
 	var wg sync.WaitGroup
 	wg.Add(10)
@@ -280,8 +287,6 @@ func TestVMessGCM(t *testing.T) {
 		}()
 	}
 	wg.Wait()
-
-	CloseAllServers(servers)
 }
 
 func TestVMessGCMUDP(t *testing.T) {