doc: add info for customize building

README.md

@@ -71,15 +71,9 @@ we can set up local listeners as proxy servers, and forward requests to internet
 
 ## Install
 
-Binary Download:
+Download:
 - [https://github.com/nadoo/glider/releases](https://github.com/nadoo/glider/releases)
 
-Build from source code (requires **Go 1.15+** ):
-```bash
-git clone https://github.com/nadoo/glider
-cd glider && go build
-```
-
 ArchLinux:
 ```bash
 sudo pacman -S glider
@@ -371,9 +365,7 @@ glider -config CONFIGPATH -listen :8080 -verbose
 
 ## Service
 
-#### Scheme: 
-
-```service=SERVICE_NAME[,SERVICE_CONFIG]```
+**Scheme:** ```service=SERVICE_NAME[,SERVICE_CONFIG]```
 
 - dhcpd: 
   - service=dhcpd,INTERFACE,START_IP,END_IP
@@ -383,6 +375,26 @@ glider -config CONFIGPATH -listen :8080 -verbose
 
 - systemd: [https://github.com/nadoo/glider/blob/master/systemd/](https://github.com/nadoo/glider/blob/master/systemd/)
 
+## Customize Build
+
+You can customize and build glider by yourself if you want a smaller binary.
+
+1. Clone the source code:
+  ```bash
+  git clone https://github.com/nadoo/glider
+  ```
+2. Customize features:
+
+  ```open `feature.go` & `feature_linux.go`, comment out the packages you don't need```
+  ```bash
+  // _ "github.com/nadoo/glider/proxy/kcp"
+  ```
+
+3. Build it(requires **Go 1.15+** )
+  ```bash
+  cd glider && go build
+  ```
+
 ## Links
 
 - [ipset](https://github.com/nadoo/ipset): netlink ipset package for Go.

proxy/tls/tls.go

@@ -17,7 +17,7 @@ type TLS struct {
 	proxy  proxy.Proxy
 	addr   string
 
-	tlsConfig *stdtls.Config
+	config *stdtls.Config
 
 	serverName string
 	skipVerify bool
@@ -83,7 +83,7 @@ func NewTLSDialer(s string, d proxy.Dialer) (proxy.Dialer, error) {
 		return nil, err
 	}
 
-	p.tlsConfig = &stdtls.Config{
+	p.config = &stdtls.Config{
 		ServerName:         p.serverName,
 		InsecureSkipVerify: p.skipVerify,
 		ClientSessionCache: stdtls.NewLRUClientSessionCache(64),
@@ -114,7 +114,7 @@ func NewTLSServer(s string, p proxy.Proxy) (proxy.Server, error) {
 		return nil, err
 	}
 
-	t.tlsConfig = &stdtls.Config{
+	t.config = &stdtls.Config{
 		Certificates: []stdtls.Certificate{cert},
 		MinVersion:   stdtls.VersionTLS12,
 	}
@@ -155,7 +155,7 @@ func (s *TLS) Serve(c net.Conn) {
 	// defer c.Close()
 
 	if s.server != nil {
-		cc := stdtls.Server(c, s.tlsConfig)
+		cc := stdtls.Server(c, s.config)
 		s.server.Serve(cc)
 	}
 }
@@ -176,7 +176,7 @@ func (s *TLS) Dial(network, addr string) (net.Conn, error) {
 		return nil, err
 	}
 
-	c := stdtls.Client(cc, s.tlsConfig)
+	c := stdtls.Client(cc, s.config)
 	err = c.Handshake()
 	return c, err
 }