Add v2ray WebSocket transport

transport/v2raywebsocket/server.go

@@ -0,0 +1,138 @@
+package v2raywebsocket
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/base64"
+	"net"
+	"net/http"
+	"net/netip"
+	"strings"
+
+	"github.com/sagernet/sing-box/adapter"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+
+	"github.com/gorilla/websocket"
+)
+
+var _ adapter.V2RayServerTransport = (*Server)(nil)
+
+type Server struct {
+	ctx                 context.Context
+	handler             N.TCPConnectionHandler
+	errorHandler        E.Handler
+	httpServer          *http.Server
+	path                string
+	maxEarlyData        uint32
+	earlyDataHeaderName string
+}
+
+func NewServer(ctx context.Context, options option.V2RayWebsocketOptions, tlsConfig *tls.Config, handler N.TCPConnectionHandler, errorHandler E.Handler) *Server {
+	server := &Server{
+		ctx:                 ctx,
+		handler:             handler,
+		errorHandler:        errorHandler,
+		path:                options.Path,
+		maxEarlyData:        options.MaxEarlyData,
+		earlyDataHeaderName: options.EarlyDataHeaderName,
+	}
+	if !strings.HasPrefix(server.path, "/") {
+		server.path = "/" + server.path
+	}
+	server.httpServer = &http.Server{
+		Handler:           server,
+		ReadHeaderTimeout: C.TCPTimeout,
+		MaxHeaderBytes:    http.DefaultMaxHeaderBytes,
+		TLSConfig:         tlsConfig,
+	}
+	return server
+}
+
+var upgrader = websocket.Upgrader{
+	HandshakeTimeout: C.TCPTimeout,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+func (s *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+	if s.maxEarlyData == 0 || s.earlyDataHeaderName != "" {
+		if request.URL.Path != s.path {
+			writer.WriteHeader(http.StatusNotFound)
+			s.badRequest(request, E.New("bad path: ", request.URL.Path))
+			return
+		}
+	}
+	var (
+		earlyData []byte
+		err       error
+		conn      net.Conn
+	)
+	if s.earlyDataHeaderName == "" {
+		if strings.HasPrefix(request.URL.RequestURI(), s.path) {
+			earlyDataStr := request.URL.RequestURI()[len(s.path):]
+			earlyData, err = base64.RawURLEncoding.DecodeString(earlyDataStr)
+		} else {
+			writer.WriteHeader(http.StatusNotFound)
+			s.badRequest(request, E.New("bad path: ", request.URL.Path))
+			return
+		}
+	} else {
+		earlyDataStr := request.Header.Get(s.earlyDataHeaderName)
+		if earlyDataStr != "" {
+			earlyData, err = base64.RawURLEncoding.DecodeString(earlyDataStr)
+		}
+	}
+	if err != nil {
+		writer.WriteHeader(http.StatusBadRequest)
+		s.badRequest(request, E.Cause(err, "decode early data"))
+		return
+	}
+	wsConn, err := upgrader.Upgrade(writer, request, nil)
+	if err != nil {
+		s.badRequest(request, E.Cause(err, "upgrade websocket connection"))
+		return
+	}
+	var remoteAddr net.Addr
+	forwardFrom := request.Header.Get("X-Forwarded-For")
+	if forwardFrom != "" {
+		for _, from := range strings.Split(forwardFrom, ",") {
+			originAddr, err := netip.ParseAddr(from)
+			if err == nil {
+				remoteAddr = M.SocksaddrFrom(originAddr, 0).TCPAddr()
+				break
+			}
+		}
+	}
+	conn = &WebsocketConn{
+		Conn:       wsConn,
+		remoteAddr: remoteAddr,
+	}
+	if len(earlyData) > 0 {
+		conn = bufio.NewCachedConn(conn, buf.As(earlyData))
+	}
+	s.handler.NewConnection(request.Context(), conn, M.Metadata{})
+}
+
+func (s *Server) badRequest(request *http.Request, err error) {
+	s.errorHandler.NewError(request.Context(), E.Cause(err, "process connection from ", request.RemoteAddr))
+}
+
+func (s *Server) Serve(listener net.Listener) error {
+	if s.httpServer.TLSConfig == nil {
+		return s.httpServer.Serve(listener)
+	} else {
+		return s.httpServer.ServeTLS(listener, "", "")
+	}
+}
+
+func (s *Server) Close() error {
+	return common.Close(s.httpServer)
+}