Add SplitHTTP Browser Dialer support (#3484)

transport/internet/browser_dialer/dialer.go

@@ -0,0 +1,121 @@
+package browser_dialer
+
+import (
+	"bytes"
+	"context"
+	_ "embed"
+	"encoding/base64"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/websocket"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/platform"
+	"github.com/xtls/xray-core/common/uuid"
+)
+
+//go:embed dialer.html
+var webpage []byte
+
+var conns chan *websocket.Conn
+
+var upgrader = &websocket.Upgrader{
+	ReadBufferSize:   0,
+	WriteBufferSize:  0,
+	HandshakeTimeout: time.Second * 4,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+func init() {
+	addr := platform.NewEnvFlag(platform.BrowserDialerAddress).GetValue(func() string { return "" })
+	if addr != "" {
+		token := uuid.New()
+		csrfToken := token.String()
+		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) {
+			if r.URL.Path == "/websocket" {
+				if r.URL.Query().Get("token") == csrfToken {
+					if conn, err := upgrader.Upgrade(w, r, nil); err == nil {
+						conns <- conn
+					} else {
+						errors.LogError(context.Background(), "Browser dialer http upgrade unexpected error")
+					}
+				}
+			} else {
+				w.Write(webpage)
+			}
+		}))
+	}
+}
+
+func HasBrowserDialer() bool {
+	return conns != nil
+}
+
+func DialWS(uri string, ed []byte) (*websocket.Conn, error) {
+	data := []byte("WS " + uri)
+	if ed != nil {
+		data = append(data, " "+base64.RawURLEncoding.EncodeToString(ed)...)
+	}
+
+	return dialRaw(data)
+}
+
+func DialGet(uri string) (*websocket.Conn, error) {
+	data := []byte("GET " + uri)
+	return dialRaw(data)
+}
+
+func DialPost(uri string, payload []byte) error {
+	data := []byte("POST " + uri)
+	conn, err := dialRaw(data)
+	if err != nil {
+		return err
+	}
+
+	err = conn.WriteMessage(websocket.BinaryMessage, payload)
+	if err != nil {
+		return err
+	}
+
+	err = CheckOK(conn)
+	if err != nil {
+		return err
+	}
+
+	conn.Close()
+	return nil
+}
+
+func dialRaw(data []byte) (*websocket.Conn, error) {
+	var conn *websocket.Conn
+	for {
+		conn = <-conns
+		if conn.WriteMessage(websocket.TextMessage, data) != nil {
+			conn.Close()
+		} else {
+			break
+		}
+	}
+	err := CheckOK(conn)
+	if err != nil {
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func CheckOK(conn *websocket.Conn) error {
+	if _, p, err := conn.ReadMessage(); err != nil {
+		conn.Close()
+		return err
+	} else if s := string(p); s != "ok" {
+		conn.Close()
+		return errors.New(s)
+	}
+
+	return nil
+}