add user-agent option for http/http2

chain.go

@@ -150,7 +150,8 @@ func (c *Chain) dialWithOptions(addr string, options *ChainOptions) (net.Conn, e
 		return nil, err
 	}
 
-	cc, err := route.LastNode().Client.Connect(conn, ipAddr, AddrConnectOption(addr))
+	cOpts := append([]ConnectOption{AddrConnectOption(addr)}, route.LastNode().ConnectOptions...)
+	cc, err := route.LastNode().Client.Connect(conn, ipAddr, cOpts...)
 	if err != nil {
 		conn.Close()
 		return nil, err
@@ -233,7 +234,7 @@ func (c *Chain) getConn() (conn net.Conn, err error) {
 	preNode := node
 	for _, node := range nodes[1:] {
 		var cc net.Conn
-		cc, err = preNode.Client.Connect(cn, node.Addr)
+		cc, err = preNode.Client.Connect(cn, node.Addr, preNode.ConnectOptions...)
 		if err != nil {
 			cn.Close()
 			node.MarkDead()

client.go

@@ -238,10 +238,11 @@ func QUICConfigHandshakeOption(config *QUICConfig) HandshakeOption {
 
 // ConnectOptions describes the options for Connector.Connect.
 type ConnectOptions struct {
-	Addr     string
-	Timeout  time.Duration
-	User     *url.Userinfo
-	Selector gosocks5.Selector
+	Addr      string
+	Timeout   time.Duration
+	User      *url.Userinfo
+	Selector  gosocks5.Selector
+	UserAgent string
 }
 
 // ConnectOption allows a common way to set ConnectOptions.
@@ -274,3 +275,10 @@ func SelectorConnectOption(s gosocks5.Selector) ConnectOption {
 		opts.Selector = s
 	}
 }
+
+// UserAgentConnectOption specifies the HTTP user-agent header.
+func UserAgentConnectOption(ua string) ConnectOption {
+	return func(opts *ConnectOptions) {
+		opts.UserAgent = ua
+	}
+}

cmd/gost/route.go

@@ -209,6 +209,10 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		gost.TimeoutDialOption(time.Duration(timeout)*time.Second),
 	)
 
+	node.ConnectOptions = []gost.ConnectOption{
+		gost.UserAgentConnectOption(node.Get("agent")),
+	}
+
 	if host == "" {
 		host = node.Host
 	}

http.go

@@ -37,6 +37,10 @@ func (c *httpConnector) Connect(conn net.Conn, addr string, options ...ConnectOp
 	if timeout <= 0 {
 		timeout = ConnectTimeout
 	}
+	ua := opts.UserAgent
+	if ua == "" {
+		ua = DefaultUserAgent
+	}
 
 	conn.SetDeadline(time.Now().Add(timeout))
 	defer conn.SetDeadline(time.Time{})
@@ -49,7 +53,7 @@ func (c *httpConnector) Connect(conn net.Conn, addr string, options ...ConnectOp
 		ProtoMinor: 1,
 		Header:     make(http.Header),
 	}
-	req.Header.Set("User-Agent", DefaultUserAgent)
+	req.Header.Set("User-Agent", ua)
 	req.Header.Set("Proxy-Connection", "keep-alive")
 
 	user := opts.User

http2.go

@@ -38,6 +38,10 @@ func (c *http2Connector) Connect(conn net.Conn, addr string, options ...ConnectO
 	for _, option := range options {
 		option(opts)
 	}
+	ua := opts.UserAgent
+	if ua == "" {
+		ua = DefaultUserAgent
+	}
 
 	cc, ok := conn.(*http2ClientConn)
 	if !ok {
@@ -56,8 +60,7 @@ func (c *http2Connector) Connect(conn net.Conn, addr string, options ...ConnectO
 		Host:          addr,
 		ContentLength: -1,
 	}
-	// DEPRECATED
-	//req.Header.Set("Gost-Target", addr)
+	req.Header.Set("User-Agent", ua)
 
 	user := opts.User
 	if user == nil {

node.go

@@ -28,6 +28,7 @@ type Node struct {
 	Values           url.Values
 	DialOptions      []DialOption
 	HandshakeOptions []HandshakeOption
+	ConnectOptions   []ConnectOption
 	Client           *Client
 	marker           *failMarker
 	Bypass           *Bypass
@@ -129,18 +130,19 @@ func (node *Node) Get(key string) string {
 	return node.Values.Get(key)
 }
 
-// GetBool likes Get, but convert parameter value to bool.
+// GetBool converts node parameter value to bool.
 func (node *Node) GetBool(key string) bool {
 	b, _ := strconv.ParseBool(node.Values.Get(key))
 	return b
 }
 
-// GetInt likes Get, but convert parameter value to int.
+// GetInt converts node parameter value to int.
 func (node *Node) GetInt(key string) int {
 	n, _ := strconv.Atoi(node.Values.Get(key))
 	return n
 }
 
+// GetDuration converts node parameter value to time.Duration.
 func (node *Node) GetDuration(key string) time.Duration {
 	d, _ := time.ParseDuration(node.Values.Get(key))
 	return d