Browser Dialer: Allow being switched on runtime when Xray is used as a lib (#5978)

https://github.com/XTLS/Xray-core/pull/5978#issuecomment-4279520473

https://github.com/XTLS/Xray-core/pull/5978#issuecomment-4320401635

transport/internet/browser_dialer/dialer.go

@@ -7,6 +7,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"net/http"
+	"sync"
 	"time"
 
 	"github.com/gorilla/websocket"
@@ -26,6 +27,8 @@ type task struct {
 }
 
 var conns chan *websocket.Conn
+var server *http.Server
+var mu sync.Mutex
 
 var upgrader = &websocket.Upgrader{
 	ReadBufferSize:   0,
@@ -36,14 +39,33 @@ var upgrader = &websocket.Upgrader{
 	},
 }
 
-func init() {
+// Used by external projects when using xray as a go module
+func Reload() {
 	addr := platform.NewEnvFlag(platform.BrowserDialerAddress).GetValue(func() string { return "" })
+	mu.Lock()
+	defer mu.Unlock()
+
+	if server != nil {
+		server.Close()
+	}
+	if HasBrowserDialer() {
+		for len(conns) > 0 {
+			select {
+				case c := <-conns:
+					c.Close()
+				default:
+			}
+		}
+		conns = nil
+	}
 	if addr != "" {
 		token := uuid.New()
 		csrfToken := token.String()
-		webpage = bytes.ReplaceAll(webpage, []byte("csrfToken"), []byte(csrfToken))
+		webpage := bytes.ReplaceAll(webpage, []byte("csrfToken"), []byte(csrfToken))
 		conns = make(chan *websocket.Conn, 256)
-		go http.ListenAndServe(addr, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		server = &http.Server{
+			Addr: addr,
+			Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				if r.URL.Path == "/websocket" {
 					if r.URL.Query().Get("token") == csrfToken {
 						if conn, err := upgrader.Upgrade(w, r, nil); err == nil {
@@ -56,7 +78,9 @@ func init() {
 					w.Header().Set("Access-Control-Allow-Origin", "*");
 					w.Write(webpage)
 				}
-		}))
+			}),
+		}
+		go server.ListenAndServe()
 	}
 }
 
@@ -194,3 +218,8 @@ func CheckOK(conn *websocket.Conn) error {
 
 	return nil
 }
+
+func init() {
+	Reload()
+}
+