diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index fae1338..34e4b6c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -11,6 +11,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+      - name: Unshallow
+        run: git fetch --prune --unshallow
       - name: Set up Go
         uses: actions/setup-go@v1
         with:
diff --git a/.goreleaser.yml b/.goreleaser.yml
index 8d853a1..ec8ed08 100644
--- a/.goreleaser.yml
+++ b/.goreleaser.yml
@@ -21,7 +21,7 @@ before:
 builds:
   - id: default
     env:
-    - CGO_ENABLED=0
+      - CGO_ENABLED=0
     goos:
       - windows
       - linux
diff --git a/go.mod b/go.mod
index 09775a7..69d58f3 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 	github.com/xtaci/kcp-go v5.4.20+incompatible
 	golang.org/x/crypto v0.0.0-20200403201458-baeed622b8d8
 	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e // indirect
-	golang.org/x/sys v0.0.0-20200331124033-c3d80250170d // indirect
+	golang.org/x/sys v0.0.0-20200406113430-c6e801f48ba2 // indirect
 )
 
 // Replace dependency modules with local developing copy
diff --git a/go.sum b/go.sum
index c11d598..ba23a95 100644
--- a/go.sum
+++ b/go.sum
@@ -73,8 +73,8 @@ golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/nt
 golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191020212454-3e7259c5e7c2/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200331124033-c3d80250170d h1:nc5K6ox/4lTFbMVSL9WRR81ixkcwXThoiF6yf+R9scA=
-golang.org/x/sys v0.0.0-20200331124033-c3d80250170d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200406113430-c6e801f48ba2 h1:Z9pPywZscwuw0ijrLEbTzW9lppFgBY4HDgbvoDnreQs=
+golang.org/x/sys v0.0.0-20200406113430-c6e801f48ba2/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/ipset/ipset_linux.go b/ipset/ipset_linux.go
index eb995e7..01ce51c 100644
--- a/ipset/ipset_linux.go
+++ b/ipset/ipset_linux.go
@@ -89,7 +89,8 @@ func NewManager(rules []*rule.Config) (*Manager, error) {
 		Family: syscall.AF_NETLINK,
 	}
 
-	if err = syscall.Bind(fd, &lsa); err != nil {
+	err = syscall.Bind(fd, &lsa)
+	if err != nil {
 		log.F("%s", err)
 		return nil, err
 	}
@@ -123,16 +124,18 @@ func NewManager(rules []*rule.Config) (*Manager, error) {
 
 // AddDomainIP implements the DNSAnswerHandler function, used to update ipset according to domainSet rule
 func (m *Manager) AddDomainIP(domain, ip string) error {
-	if ip != "" {
-		domainParts := strings.Split(domain, ".")
-		length := len(domainParts)
-		for i := length - 1; i >= 0; i-- {
-			domain := strings.Join(domainParts[i:length], ".")
+	if domain == "" || ip == "" {
+		return errors.New("please specify the domain and ip address")
+	}
 
-			// find in domainMap
-			if ipset, ok := m.domainSet.Load(domain); ok {
-				AddToSet(m.fd, m.lsa, ipset.(string), ip)
-			}
+	domainParts := strings.Split(domain, ".")
+	length := len(domainParts)
+	for i := length - 1; i >= 0; i-- {
+		domain := strings.Join(domainParts[i:length], ".")
+
+		// find in domainMap
+		if ipset, ok := m.domainSet.Load(domain); ok {
+			AddToSet(m.fd, m.lsa, ipset.(string), ip)
 		}
 	}
 
diff --git a/proxy/obfs/http.go b/proxy/obfs/http.go
index 3942824..fd4c48b 100644
--- a/proxy/obfs/http.go
+++ b/proxy/obfs/http.go
@@ -42,7 +42,7 @@ func (p *HTTPObfs) NewConn(c net.Conn) (net.Conn, error) {
 }
 
 func (c *HTTPObfsConn) writeHeader() (int, error) {
-	buf := new(bytes.Buffer)
+	var buf bytes.Buffer
 	buf.WriteString("GET " + c.obfsURI + " HTTP/1.1\r\n")
 	buf.WriteString("Host: " + c.obfsHost + "\r\n")
 	buf.WriteString("User-Agent: " + c.obfsUA + "\r\n")
diff --git a/proxy/obfs/tls.go b/proxy/obfs/tls.go
index ffb070a..7bab773 100644
--- a/proxy/obfs/tls.go
+++ b/proxy/obfs/tls.go
@@ -69,9 +69,9 @@ func (c *TLSObfsConn) Write(b []byte) (int, error) {
 			end = n
 		}
 
-		buf := new(bytes.Buffer)
+		var buf bytes.Buffer
 		buf.Write([]byte{0x17, 0x03, 0x03})
-		binary.Write(buf, binary.BigEndian, uint16(len(b[i:end])))
+		binary.Write(&buf, binary.BigEndian, uint16(len(b[i:end])))
 		buf.Write(b[i:end])
 
 		_, err := c.Conn.Write(buf.Bytes())
@@ -124,7 +124,7 @@ func (c *TLSObfsConn) Read(b []byte) (int, error) {
 }
 
 func (c *TLSObfsConn) handshake(b []byte) (int, error) {
-	buf := new(bytes.Buffer)
+	var buf bytes.Buffer
 
 	// prepare extension & clientHello content
 	bufExt, bufHello := extension(b, c.obfsHost), clientHello()
@@ -142,7 +142,7 @@ func (c *TLSObfsConn) handshake(b []byte) (int, error) {
 	buf.Write([]byte{0x03, 0x01})
 
 	// length
-	binary.Write(buf, binary.BigEndian, uint16(handshakeLen))
+	binary.Write(&buf, binary.BigEndian, uint16(handshakeLen))
 
 	// Handshake Begin
 	// Handshake Type: Client Hello (1)
@@ -156,7 +156,7 @@ func (c *TLSObfsConn) handshake(b []byte) (int, error) {
 
 	// Extension Begin
 	// ext content length
-	binary.Write(buf, binary.BigEndian, uint16(extLen))
+	binary.Write(&buf, binary.BigEndian, uint16(extLen))
 
 	// ext content
 	buf.Write(bufExt.Bytes())
@@ -170,7 +170,7 @@ func (c *TLSObfsConn) handshake(b []byte) (int, error) {
 }
 
 func clientHello() *bytes.Buffer {
-	buf := new(bytes.Buffer)
+	var buf bytes.Buffer
 
 	// Version: TLS 1.2 (0x0303)
 	buf.Write([]byte{0x03, 0x03})
@@ -182,7 +182,7 @@ func clientHello() *bytes.Buffer {
 	// clients do not send current time, and server do not check it,
 	// golang tls client and chrome browser send random bytes instead.
 	//
-	binary.Write(buf, binary.BigEndian, uint32(time.Now().Unix()))
+	binary.Write(&buf, binary.BigEndian, uint32(time.Now().Unix()))
 	random := make([]byte, 28)
 	// The above 2 lines of codes was added to make it compatible with some server implementation,
 	// if we don't need the compatibility, just use the following code instead.
@@ -200,7 +200,7 @@ func clientHello() *bytes.Buffer {
 
 	// https://github.com/shadowsocks/simple-obfs/blob/7659eeccf473aa41eb294e92c32f8f60a8747325/src/obfs_tls.c#L57
 	// Cipher Suites Length: 56
-	binary.Write(buf, binary.BigEndian, uint16(56))
+	binary.Write(&buf, binary.BigEndian, uint16(56))
 	// Cipher Suites (28 suites)
 	buf.Write([]byte{
 		0xc0, 0x2c, 0xc0, 0x30, 0x00, 0x9f, 0xcc, 0xa9, 0xcc, 0xa8, 0xcc, 0xaa, 0xc0, 0x2b, 0xc0, 0x2f,
@@ -214,55 +214,55 @@ func clientHello() *bytes.Buffer {
 	// Compression Methods (1 method)
 	buf.WriteByte(0x00)
 
-	return buf
+	return &buf
 }
 
 func extension(b []byte, server string) *bytes.Buffer {
-	buf := new(bytes.Buffer)
+	var buf bytes.Buffer
 
 	// Extension: SessionTicket TLS
 	buf.Write([]byte{0x00, 0x23}) // type
 	// NOTE: send some data in sessionticket, the server will treat it as data too
-	binary.Write(buf, binary.BigEndian, uint16(len(b))) // length
+	binary.Write(&buf, binary.BigEndian, uint16(len(b))) // length
 	buf.Write(b)
 
 	// Extension: server_name
-	buf.Write([]byte{0x00, 0x00})                              // type
-	binary.Write(buf, binary.BigEndian, uint16(len(server)+5)) // length
-	binary.Write(buf, binary.BigEndian, uint16(len(server)+3)) // Server Name list length
-	buf.WriteByte(0x00)                                        // Server Name Type: host_name (0)
-	binary.Write(buf, binary.BigEndian, uint16(len(server)))   // Server Name length
+	buf.Write([]byte{0x00, 0x00})                               // type
+	binary.Write(&buf, binary.BigEndian, uint16(len(server)+5)) // length
+	binary.Write(&buf, binary.BigEndian, uint16(len(server)+3)) // Server Name list length
+	buf.WriteByte(0x00)                                         // Server Name Type: host_name (0)
+	binary.Write(&buf, binary.BigEndian, uint16(len(server)))   // Server Name length
 	buf.Write([]byte(server))
 
 	// https://github.com/shadowsocks/simple-obfs/blob/7659eeccf473aa41eb294e92c32f8f60a8747325/src/obfs_tls.c#L88
 	// Extension: ec_point_formats (len=4)
-	buf.Write([]byte{0x00, 0x0b})                  // type
-	binary.Write(buf, binary.BigEndian, uint16(4)) // length
-	buf.WriteByte(0x03)                            // format length
+	buf.Write([]byte{0x00, 0x0b})                   // type
+	binary.Write(&buf, binary.BigEndian, uint16(4)) // length
+	buf.WriteByte(0x03)                             // format length
 	buf.Write([]byte{0x01, 0x00, 0x02})
 
 	// Extension: supported_groups (len=10)
-	buf.Write([]byte{0x00, 0x0a})                   // type
-	binary.Write(buf, binary.BigEndian, uint16(10)) // length
-	binary.Write(buf, binary.BigEndian, uint16(8))  // Supported Groups List Length: 8
+	buf.Write([]byte{0x00, 0x0a})                    // type
+	binary.Write(&buf, binary.BigEndian, uint16(10)) // length
+	binary.Write(&buf, binary.BigEndian, uint16(8))  // Supported Groups List Length: 8
 	buf.Write([]byte{0x00, 0x1d, 0x00, 0x17, 0x00, 0x19, 0x00, 0x18})
 
 	// Extension: signature_algorithms (len=32)
-	buf.Write([]byte{0x00, 0x0d})                   // type
-	binary.Write(buf, binary.BigEndian, uint16(32)) // length
-	binary.Write(buf, binary.BigEndian, uint16(30)) // Signature Hash Algorithms Length: 30
+	buf.Write([]byte{0x00, 0x0d})                    // type
+	binary.Write(&buf, binary.BigEndian, uint16(32)) // length
+	binary.Write(&buf, binary.BigEndian, uint16(30)) // Signature Hash Algorithms Length: 30
 	buf.Write([]byte{
 		0x06, 0x01, 0x06, 0x02, 0x06, 0x03, 0x05, 0x01, 0x05, 0x02, 0x05, 0x03, 0x04, 0x01, 0x04, 0x02,
 		0x04, 0x03, 0x03, 0x01, 0x03, 0x02, 0x03, 0x03, 0x02, 0x01, 0x02, 0x02, 0x02, 0x03,
 	})
 
 	// Extension: encrypt_then_mac (len=0)
-	buf.Write([]byte{0x00, 0x16})                  // type
-	binary.Write(buf, binary.BigEndian, uint16(0)) // length
+	buf.Write([]byte{0x00, 0x16})                   // type
+	binary.Write(&buf, binary.BigEndian, uint16(0)) // length
 
 	// Extension: extended_master_secret (len=0)
-	buf.Write([]byte{0x00, 0x17})                  // type
-	binary.Write(buf, binary.BigEndian, uint16(0)) // length
+	buf.Write([]byte{0x00, 0x17})                   // type
+	binary.Write(&buf, binary.BigEndian, uint16(0)) // length
 
-	return buf
+	return &buf
 }
diff --git a/proxy/vmess/client.go b/proxy/vmess/client.go
index 0901a9b..8877bcd 100644
--- a/proxy/vmess/client.go
+++ b/proxy/vmess/client.go
@@ -39,7 +39,7 @@ const (
 	CmdUDP byte = 2
 )
 
-// Client vmess client
+// Client is a vmess client
 type Client struct {
 	users    []*User
 	count    int
@@ -68,7 +68,7 @@ type Conn struct {
 	dataWriter io.Writer
 }
 
-// NewClient .
+// NewClient returns a new vmess client.
 func NewClient(uuidStr, security string, alterID int) (*Client, error) {
 	uuid, err := StrToUUID(uuidStr)
 	if err != nil {
@@ -105,7 +105,7 @@ func NewClient(uuidStr, security string, alterID int) (*Client, error) {
 	return c, nil
 }
 
-// NewConn .
+// NewConn returns a new vmess conn.
 func (c *Client) NewConn(rc net.Conn, target string) (*Conn, error) {
 	r := rand.Intn(c.count)
 	conn := &Conn{user: c.users[r], opt: c.opt, security: c.security}
@@ -158,9 +158,9 @@ func (c *Conn) EncodeAuthInfo() []byte {
 	return h.Sum(nil)
 }
 
-// EncodeRequest encodes requests to network bytes
+// EncodeRequest encodes requests to network bytes.
 func (c *Conn) EncodeRequest() ([]byte, error) {
-	buf := new(bytes.Buffer)
+	var buf bytes.Buffer
 
 	// Request
 	buf.WriteByte(1)           // Ver
@@ -178,7 +178,7 @@ func (c *Conn) EncodeRequest() ([]byte, error) {
 	buf.WriteByte(CmdTCP) // cmd
 
 	// target
-	err := binary.Write(buf, binary.BigEndian, uint16(c.port)) // port
+	err := binary.Write(&buf, binary.BigEndian, uint16(c.port)) // port
 	if err != nil {
 		return nil, err
 	}
@@ -212,7 +212,7 @@ func (c *Conn) EncodeRequest() ([]byte, error) {
 	return buf.Bytes(), nil
 }
 
-// DecodeRespHeader .
+// DecodeRespHeader decodes response header.
 func (c *Conn) DecodeRespHeader() error {
 	block, err := aes.NewCipher(c.respBodyKey[:])
 	if err != nil {
diff --git a/proxy/ws/ws.go b/proxy/ws/ws.go
index 3c75151..e798659 100644
--- a/proxy/ws/ws.go
+++ b/proxy/ws/ws.go
@@ -39,8 +39,7 @@ func NewWS(s string, d proxy.Dialer) (*WS, error) {
 		addr = d.Addr()
 	}
 
-	query := u.Query()
-	host := query.Get("host")
+	host := u.Query().Get("host")
 	if host == "" {
 		colonPos := strings.LastIndex(addr, ":")
 		if colonPos == -1 {