diff --git a/feature.go b/feature.go
index 1884cab..21b49fc 100644
--- a/feature.go
+++ b/feature.go
@@ -7,14 +7,12 @@ import (
 	// comment out the protocols you don't need to make the compiled binary smaller.
 	_ "github.com/nadoo/glider/proxy/http"
 	_ "github.com/nadoo/glider/proxy/kcp"
-
 	_ "github.com/nadoo/glider/proxy/mixed"
 	_ "github.com/nadoo/glider/proxy/obfs"
 	_ "github.com/nadoo/glider/proxy/pxyproto"
 	_ "github.com/nadoo/glider/proxy/reject"
 	_ "github.com/nadoo/glider/proxy/smux"
 	_ "github.com/nadoo/glider/proxy/socks4"
-
 	_ "github.com/nadoo/glider/proxy/socks5"
 	_ "github.com/nadoo/glider/proxy/ss"
 	_ "github.com/nadoo/glider/proxy/ssh"
@@ -22,7 +20,6 @@ import (
 	_ "github.com/nadoo/glider/proxy/tcp"
 	_ "github.com/nadoo/glider/proxy/tls"
 	_ "github.com/nadoo/glider/proxy/trojan"
-
 	_ "github.com/nadoo/glider/proxy/udp"
 	_ "github.com/nadoo/glider/proxy/vless"
 	_ "github.com/nadoo/glider/proxy/vmess"
diff --git a/feature_linux.go b/feature_linux.go
index be2c2c7..cc254ae 100644
--- a/feature_linux.go
+++ b/feature_linux.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	// comment out the services you don't need to make the compiled binary smaller.
-	// _ "github.com/nadoo/glider/service/xxx"
 	_ "github.com/nadoo/glider/service/dhcpd"
 
 	// comment out the protocols you don't need to make the compiled binary smaller.
diff --git a/go.mod b/go.mod
index 3c8d0e8..9a7f805 100644
--- a/go.mod
+++ b/go.mod
@@ -11,7 +11,7 @@ require (
 	github.com/nadoo/conflag v0.3.1
 	github.com/nadoo/ipset v0.4.1-0.20220218075046-ca3cdce74266
 	github.com/xtaci/kcp-go/v5 v5.6.1
-	golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70
+	golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000
 	golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5
 )
 
diff --git a/go.sum b/go.sum
index 7f1e8d2..6e704e3 100644
--- a/go.sum
+++ b/go.sum
@@ -111,8 +111,8 @@ golang.org/x/crypto v0.0.0-20191219195013-becbf705a915/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201012173705-84dcc777aaee/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70 h1:syTAU9FwmvzEoIYMqcPHOcVm4H3U5u90WsvuYgwpETU=
-golang.org/x/crypto v0.0.0-20220307211146-efcb8507fb70/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000 h1:SL+8VVnkqyshUSz5iNnXtrBQzvFF2SkROm6t5RczFAE=
+golang.org/x/crypto v0.0.0-20220313003712-b769efc7c000/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
diff --git a/ipset/ipset_other.go b/ipset/ipset_other.go
index 22cfb22..94e2692 100644
--- a/ipset/ipset_other.go
+++ b/ipset/ipset_other.go
@@ -1,5 +1,4 @@
 //go:build !linux
-// +build !linux
 
 package ipset
 
diff --git a/pkg/sockopt/sockopt_others.go b/pkg/sockopt/sockopt_others.go
index c426e56..ced5450 100644
--- a/pkg/sockopt/sockopt_others.go
+++ b/pkg/sockopt/sockopt_others.go
@@ -1,5 +1,4 @@
 //go:build !linux && !darwin
-// +build !linux,!darwin
 
 package sockopt
 
diff --git a/proxy/proxy.go b/proxy/proxy.go
index afc5dfc..bbc3e97 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -1,6 +1,9 @@
 package proxy
 
-import "net"
+import (
+	"net"
+	"strings"
+)
 
 // Proxy is a dialer manager.
 type Proxy interface {
@@ -16,3 +19,26 @@ type Proxy interface {
 	// Record records result while using the dialer from proxy.
 	Record(dialer Dialer, success bool)
 }
+
+var usages = make(map[string]string)
+
+// AddUsage adds help message for the named proxy.
+func AddUsage(name, usage string) { usages[name] = usage }
+
+// Usage returns help message of the named proxy.
+func Usage(name string) string {
+	if name == "all" {
+		var msg strings.Builder
+		for _, usage := range usages {
+			msg.WriteString(usage)
+			msg.WriteString("\n--")
+		}
+		return msg.String()
+	}
+
+	if usage, ok := usages[name]; ok {
+		return usage
+	}
+
+	return "can not find usage for: " + name
+}
diff --git a/proxy/redir/redir_linux_other.go b/proxy/redir/redir_linux_other.go
index d02c54a..8ef2b8f 100644
--- a/proxy/redir/redir_linux_other.go
+++ b/proxy/redir/redir_linux_other.go
@@ -1,5 +1,4 @@
 //go:build linux && !386
-// +build linux,!386
 
 package redir
 
diff --git a/proxy/usage.go b/proxy/usage.go
deleted file mode 100644
index d9a1241..0000000
--- a/proxy/usage.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package proxy
-
-import "strings"
-
-var (
-	msg    strings.Builder
-	usages = make(map[string]string)
-)
-
-// AddUsage adds help message for the named proxy.
-func AddUsage(name, usage string) {
-	usages[name] = usage
-	msg.WriteString(usage)
-	msg.WriteString("\n--")
-}
-
-// Usage returns help message of the named proxy.
-func Usage(name string) string {
-	if name == "all" {
-		return msg.String()
-	}
-	if usage, ok := usages[name]; ok {
-		return usage
-	}
-	return "can not find usage for: " + name
-}