diff --git a/dns/client.go b/dns/client.go
index 5b57ae3..e280024 100644
--- a/dns/client.go
+++ b/dns/client.go
@@ -233,21 +233,18 @@ func (c *Client) exchangeUDP(rc net.Conn, reqBytes []byte) ([]byte, error) {
 
 // SetServers sets upstream dns servers for the given domain.
 func (c *Client) SetServers(domain string, servers []string) {
-	c.upStreamMap[domain] = NewUPStream(servers)
+	c.upStreamMap[strings.ToLower(domain)] = NewUPStream(servers)
 }
 
 // UpStream returns upstream dns server for the given domain.
 func (c *Client) UpStream(domain string) *UPStream {
-	domainParts := strings.Split(domain, ".")
-	length := len(domainParts)
-	for i := length - 1; i >= 0; i-- {
-		domain := strings.Join(domainParts[i:length], ".")
-
-		if upstream, ok := c.upStreamMap[domain]; ok {
+	domain = strings.ToLower(domain)
+	for i := len(domain); i != -1; {
+		i = strings.LastIndexByte(domain[:i], '.')
+		if upstream, ok := c.upStreamMap[domain[i+1:]]; ok {
 			return upstream
 		}
 	}
-
 	return c.upStream
 }
 
diff --git a/go.mod b/go.mod
index 2f0ee04..4a2edf2 100644
--- a/go.mod
+++ b/go.mod
@@ -10,8 +10,8 @@ require (
 	github.com/xtaci/kcp-go/v5 v5.5.15
 	golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de
 	golang.org/x/net v0.0.0-20200813134508-3edf25e44fcc // indirect
-	golang.org/x/sys v0.0.0-20200812155832-6a926be9bd1d // indirect
-	golang.org/x/tools v0.0.0-20200813231717-0a73ddcff9b8 // indirect
+	golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed // indirect
+	golang.org/x/tools v0.0.0-20200815165600-90abf76919f3 // indirect
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
 )
 
diff --git a/go.sum b/go.sum
index a795d0c..18671e7 100644
--- a/go.sum
+++ b/go.sum
@@ -115,15 +115,15 @@ golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200501145240-bc7a7d42d5c3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200808120158-1030fc2bf1d9 h1:yi1hN8dcqI9l8klZfy4B8mJvFmmAxJEePIQQFNSd7Cs=
 golang.org/x/sys v0.0.0-20200808120158-1030fc2bf1d9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200812155832-6a926be9bd1d h1:QQrM/CCYEzTs91GZylDCQjGHudbPTxF/1fvXdVh5lMo=
-golang.org/x/sys v0.0.0-20200812155832-6a926be9bd1d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed h1:J22ig1FUekjjkmZUM7pTKixYm8DvrYsvrBZdunYeIuQ=
+golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c h1:iHhCR0b26amDCiiO+kBguKZom9aMF+NrFxh9zeKR/XU=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.0.0-20200813231717-0a73ddcff9b8 h1:+hbnCVs7yJ18cZmTc/aRTUmFIr+z6I1lnMjyeMJJGEM=
-golang.org/x/tools v0.0.0-20200813231717-0a73ddcff9b8/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
+golang.org/x/tools v0.0.0-20200815165600-90abf76919f3 h1:0aScV/0rLmANzEYIhjCOi2pTvDyhZNduBUMD2q3iqs4=
+golang.org/x/tools v0.0.0-20200815165600-90abf76919f3/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
diff --git a/ipset/ipset_linux.go b/ipset/ipset_linux.go
index 0009e8a..4be93dd 100644
--- a/ipset/ipset_linux.go
+++ b/ipset/ipset_linux.go
@@ -128,18 +128,13 @@ func (m *Manager) AddDomainIP(domain, ip string) error {
 	if domain == "" || ip == "" {
 		return errors.New("please specify the domain and ip address")
 	}
-
-	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 {
+	domain = strings.ToLower(domain)
+	for i := len(domain); i != -1; {
+		i = strings.LastIndexByte(domain[:i], '.')
+		if ipset, ok := m.domainSet.Load(domain[i+1:]); ok {
 			AddToSet(m.fd, m.lsa, ipset.(string), ip)
 		}
 	}
-
 	return nil
 }
 
diff --git a/main.go b/main.go
index bea6e06..db7d692 100644
--- a/main.go
+++ b/main.go
@@ -34,7 +34,7 @@ import (
 	_ "github.com/nadoo/glider/proxy/ws"
 )
 
-var version = "0.10.2"
+var version = "0.10.3"
 
 func main() {
 	// read configs
diff --git a/proxy/socks5/packet.go b/proxy/socks5/packet.go
index 432f364..593429f 100644
--- a/proxy/socks5/packet.go
+++ b/proxy/socks5/packet.go
@@ -21,7 +21,7 @@ type PktConn struct {
 	ctrlConn net.Conn // tcp control conn
 }
 
-// NewPktConn returns a PktConn
+// NewPktConn returns a PktConn.
 func NewPktConn(c net.PacketConn, writeAddr net.Addr, tgtAddr socks.Addr, tgtHeader bool, ctrlConn net.Conn) *PktConn {
 	pc := &PktConn{
 		PacketConn: c,
@@ -48,7 +48,7 @@ func NewPktConn(c net.PacketConn, writeAddr net.Addr, tgtAddr socks.Addr, tgtHea
 	return pc
 }
 
-// ReadFrom overrides the original function from net.PacketConn
+// ReadFrom overrides the original function from net.PacketConn.
 func (pc *PktConn) ReadFrom(b []byte) (int, net.Addr, error) {
 	if !pc.tgtHeader {
 		return pc.PacketConn.ReadFrom(b)
@@ -90,7 +90,7 @@ func (pc *PktConn) ReadFrom(b []byte) (int, net.Addr, error) {
 	return n - len(tgtAddr) - 3, raddr, err
 }
 
-// WriteTo overrides the original function from net.PacketConn
+// WriteTo overrides the original function from net.PacketConn.
 func (pc *PktConn) WriteTo(b []byte, addr net.Addr) (int, error) {
 	if !pc.tgtHeader {
 		return pc.PacketConn.WriteTo(b, addr)
diff --git a/proxy/socks5/socks5.go b/proxy/socks5/socks5.go
index 8a3ec9d..5354438 100644
--- a/proxy/socks5/socks5.go
+++ b/proxy/socks5/socks5.go
@@ -42,7 +42,7 @@ func init() {
 	proxy.RegisterServer("socks5", NewSocks5Server)
 }
 
-// NewSocks5 returns a Proxy that makes SOCKS v5 connections to the given address
+// NewSocks5 returns a Proxy that makes SOCKS v5 connections to the given address.
 // with an optional username and password. (RFC 1928)
 func NewSocks5(s string, d proxy.Dialer, p proxy.Proxy) (*Socks5, error) {
 	u, err := url.Parse(s)
diff --git a/proxy/vmess/addr.go b/proxy/vmess/addr.go
index dfc494d..4f6d5a0 100644
--- a/proxy/vmess/addr.go
+++ b/proxy/vmess/addr.go
@@ -5,7 +5,7 @@ import (
 	"strconv"
 )
 
-// Atyp is vmess addr type
+// Atyp is vmess addr type.
 type Atyp byte
 
 // Atyp
@@ -16,13 +16,13 @@ const (
 	AtypIP6    Atyp = 3
 )
 
-// Addr is vmess addr
+// Addr is vmess addr.
 type Addr []byte
 
-// Port is vmess addr port
+// Port is vmess addr port.
 type Port uint16
 
-// ParseAddr parses the address in string s
+// ParseAddr parses the address in string s.
 func ParseAddr(s string) (Atyp, Addr, Port, error) {
 	var atyp Atyp
 	var addr Addr
diff --git a/proxy/vmess/aead.go b/proxy/vmess/aead.go
index b86b500..2309687 100644
--- a/proxy/vmess/aead.go
+++ b/proxy/vmess/aead.go
@@ -16,7 +16,7 @@ type aeadWriter struct {
 	iv    []byte
 }
 
-// AEADWriter returns a aead writer
+// AEADWriter returns a aead writer.
 func AEADWriter(w io.Writer, aead cipher.AEAD, iv []byte) io.Writer {
 	return &aeadWriter{
 		Writer: w,
@@ -79,7 +79,7 @@ type aeadReader struct {
 	iv       []byte
 }
 
-// AEADReader returns a aead reader
+// AEADReader returns a aead reader.
 func AEADReader(r io.Reader, aead cipher.AEAD, iv []byte) io.Reader {
 	return &aeadReader{
 		Reader: r,
diff --git a/proxy/vmess/chunk.go b/proxy/vmess/chunk.go
index 04f62ff..828869b 100644
--- a/proxy/vmess/chunk.go
+++ b/proxy/vmess/chunk.go
@@ -16,7 +16,7 @@ type chunkedWriter struct {
 	io.Writer
 }
 
-// ChunkedWriter returns a chunked writer
+// ChunkedWriter returns a chunked writer.
 func ChunkedWriter(w io.Writer) io.Writer {
 	return &chunkedWriter{Writer: w}
 }
@@ -52,7 +52,7 @@ type chunkedReader struct {
 	left int
 }
 
-// ChunkedReader returns a chunked reader
+// ChunkedReader returns a chunked reader.
 func ChunkedReader(r io.Reader) io.Reader {
 	return &chunkedReader{Reader: r}
 }
diff --git a/proxy/vmess/client.go b/proxy/vmess/client.go
index f391f94..370cde1 100644
--- a/proxy/vmess/client.go
+++ b/proxy/vmess/client.go
@@ -39,7 +39,7 @@ const (
 	CmdUDP byte = 2
 )
 
-// Client is a vmess client
+// Client is a vmess client.
 type Client struct {
 	users    []*User
 	count    int
@@ -47,7 +47,7 @@ type Client struct {
 	security byte
 }
 
-// Conn is a connection to vmess server
+// Conn is a connection to vmess server.
 type Conn struct {
 	user     *User
 	opt      byte
@@ -142,7 +142,7 @@ func (c *Client) NewConn(rc net.Conn, target string) (*Conn, error) {
 	return conn, nil
 }
 
-// Auth send auth info: HMAC("md5", UUID, UTC)
+// Auth send auth info: HMAC("md5", UUID, UTC).
 func (c *Conn) Auth() error {
 	ts := pool.GetBuffer(8)
 	defer pool.PutBuffer(ts)
diff --git a/proxy/vmess/user.go b/proxy/vmess/user.go
index 6a43da7..957355a 100644
--- a/proxy/vmess/user.go
+++ b/proxy/vmess/user.go
@@ -12,13 +12,13 @@ import (
 	"github.com/nadoo/glider/common/pool"
 )
 
-// User of vmess client
+// User of vmess client.
 type User struct {
 	UUID   [16]byte
 	CmdKey [16]byte
 }
 
-// NewUser .
+// NewUser returns a new user.
 func NewUser(uuid [16]byte) *User {
 	u := &User{UUID: uuid}
 	copy(u.CmdKey[:], GetKey(uuid))
@@ -38,7 +38,7 @@ func nextID(oldID [16]byte) (newID [16]byte) {
 	}
 }
 
-// GenAlterIDUsers generates users according to primary user's id and alterID
+// GenAlterIDUsers generates users according to primary user's id and alterID.
 func (u *User) GenAlterIDUsers(alterID int) []*User {
 	users := make([]*User, alterID)
 	preID := u.UUID
@@ -63,7 +63,7 @@ func StrToUUID(s string) (uuid [16]byte, err error) {
 	return
 }
 
-// GetKey returns the key of AES-128-CFB encrypter
+// GetKey returns the key of AES-128-CFB encrypter.
 // Key：MD5(UUID + []byte('c48619fe-8f02-49e0-b9e9-edf763e17e21'))
 func GetKey(uuid [16]byte) []byte {
 	md5hash := md5.New()
@@ -72,7 +72,7 @@ func GetKey(uuid [16]byte) []byte {
 	return md5hash.Sum(nil)
 }
 
-// TimestampHash returns the iv of AES-128-CFB encrypter
+// TimestampHash returns the iv of AES-128-CFB encrypter.
 // IV：MD5(X + X + X + X)，X = []byte(timestamp.now) (8 bytes, Big Endian)
 func TimestampHash(t time.Time) []byte {
 	ts := pool.GetBuffer(8)
diff --git a/rule/config.go b/rule/config.go
index 6170a03..895b41b 100644
--- a/rule/config.go
+++ b/rule/config.go
@@ -11,7 +11,7 @@ import (
 	"github.com/nadoo/glider/strategy"
 )
 
-// Config , every rule dialer points to a rule file
+// Config of rule dialer.
 type Config struct {
 	Name string
 
@@ -26,7 +26,7 @@ type Config struct {
 	CIDR   []string
 }
 
-// NewConfFromFile .
+// NewConfFromFile returns a new config from file.
 func NewConfFromFile(ruleFile string) (*Config, error) {
 	p := &Config{Name: ruleFile}
 
@@ -58,7 +58,7 @@ func NewConfFromFile(ruleFile string) (*Config, error) {
 	return p, err
 }
 
-// ListDir returns file list named with suffix in dirPth
+// ListDir returns file list named with suffix in dirPth.
 func ListDir(dirPth string, suffix string) (files []string, err error) {
 	files = make([]string, 0, 10)
 	dir, err := ioutil.ReadDir(dirPth)
@@ -66,12 +66,12 @@ func ListDir(dirPth string, suffix string) (files []string, err error) {
 		return nil, err
 	}
 	PthSep := string(os.PathSeparator)
-	suffix = strings.ToUpper(suffix)
+	suffix = strings.ToLower(suffix)
 	for _, fi := range dir {
 		if fi.IsDir() {
 			continue
 		}
-		if strings.HasSuffix(strings.ToUpper(fi.Name()), suffix) {
+		if strings.HasSuffix(strings.ToLower(fi.Name()), suffix) {
 			files = append(files, dirPth+PthSep+fi.Name())
 		}
 	}
diff --git a/rule/rule.go b/rule/rule.go
index dfe9eea..07b3cdc 100644
--- a/rule/rule.go
+++ b/rule/rule.go
@@ -10,7 +10,7 @@ import (
 	"github.com/nadoo/glider/strategy"
 )
 
-// Proxy struct
+// Proxy struct.
 type Proxy struct {
 	proxy   *strategy.Proxy
 	proxies []*strategy.Proxy
@@ -90,13 +90,10 @@ func (p *Proxy) nextProxy(dstAddr string) *strategy.Proxy {
 
 	}
 
-	domainParts := strings.Split(host, ".")
-	length := len(domainParts)
-	for i := length - 1; i >= 0; i-- {
-		domain := strings.Join(domainParts[i:length], ".")
-
-		// find in domainMap
-		if proxy, ok := p.domainMap.Load(domain); ok {
+	host = strings.ToLower(host)
+	for i := len(host); i != -1; {
+		i = strings.LastIndexByte(host[:i], '.')
+		if proxy, ok := p.domainMap.Load(host[i+1:]); ok {
 			return proxy.(*strategy.Proxy)
 		}
 	}
@@ -117,15 +114,12 @@ func (p *Proxy) Record(dialer proxy.Dialer, success bool) {
 // AddDomainIP used to update ipMap rules according to domainMap rule.
 func (p *Proxy) AddDomainIP(domain, ip string) error {
 	if ip != "" {
-		domainParts := strings.Split(domain, ".")
-		length := len(domainParts)
-		for i := length - 1; i >= 0; i-- {
-			pDomain := strings.ToLower(strings.Join(domainParts[i:length], "."))
-
-			// find in domainMap
-			if dialer, ok := p.domainMap.Load(pDomain); ok {
+		domain = strings.ToLower(domain)
+		for i := len(domain); i != -1; {
+			i = strings.LastIndexByte(domain[:i], '.')
+			if dialer, ok := p.domainMap.Load(domain[i+1:]); ok {
 				p.ipMap.Store(ip, dialer)
-				log.F("[rule] add ip=%s, based on rule: domain=%s & domain/ip: %s/%s\n", ip, pDomain, domain, ip)
+				log.F("[rule] add ip=%s, based on rule: domain=%s & domain/ip: %s/%s\n", ip, domain[i+1:], domain, ip)
 			}
 		}
 	}