Fix VLESS fallbacks SNI shunt

proxy/vless/inbound/inbound.go

@@ -109,10 +109,11 @@ func New(ctx context.Context, config *Config, dc dns.Client) (*Handler, error) {
 				}
 			*/
 		}
-		if handler.fallbacks[""] != nil {
-			for alpn, pfb := range handler.fallbacks {
+		for _, apfb := range handler.fallbacks {
+			if apfb[""] != nil {
+				for alpn, pfb := range apfb {
 					if alpn != "" { // && alpn != "h2" {
-					for path, fb := range handler.fallbacks[""] {
+						for path, fb := range apfb[""] {
 							if pfb[path] == nil {
 								pfb[path] = fb
 							}
@@ -121,6 +122,23 @@ func New(ctx context.Context, config *Config, dc dns.Client) (*Handler, error) {
 				}
 			}
 		}
+		if handler.fallbacks[""] != nil {
+			for name, apfb := range handler.fallbacks {
+				if name != "" {
+					for alpn, pfb := range handler.fallbacks[""] {
+						if apfb[alpn] == nil {
+							apfb[alpn] = make(map[string]*Fallback)
+						}
+						for path, fb := range pfb {
+							if apfb[alpn][path] == nil {
+								apfb[alpn][path] = fb
+							}
+						}
+					}
+				}
+			}
+		}
+	}
 
 	return handler, nil
 }
@@ -175,8 +193,8 @@ func (h *Handler) Process(ctx context.Context, network net.Network, connection i
 	var requestAddons *encoding.Addons
 	var err error
 
-	apfb := h.fallbacks
-	isfb := apfb != nil
+	napfb := h.fallbacks
+	isfb := napfb != nil
 
 	if isfb && firstLen < 18 {
 		err = newError("fallback directly")
@@ -193,36 +211,44 @@ func (h *Handler) Process(ctx context.Context, network net.Network, connection i
 
 			name := ""
 			alpn := ""
-			if len(apfb) > 1 || apfb[""] == nil {
 			if tlsConn, ok := iConn.(*tls.Conn); ok {
-					name = tlsConn.ConnectionState().ServerName
-					alpn = tlsConn.ConnectionState().NegotiatedProtocol
-					newError("realServerName = " + name).AtInfo().WriteToLog(sid)
+				cs := tlsConn.ConnectionState()
+				name = cs.ServerName
+				alpn = cs.NegotiatedProtocol
+				newError("realName = " + name).AtInfo().WriteToLog(sid)
 				newError("realAlpn = " + alpn).AtInfo().WriteToLog(sid)
 			} else if xtlsConn, ok := iConn.(*xtls.Conn); ok {
-					name = xtlsConn.ConnectionState().ServerName
-					alpn = xtlsConn.ConnectionState().NegotiatedProtocol
-					newError("realServerName = " + name).AtInfo().WriteToLog(sid)
+				cs := xtlsConn.ConnectionState()
+				name = cs.ServerName
+				alpn = cs.NegotiatedProtocol
+				newError("realName = " + name).AtInfo().WriteToLog(sid)
 				newError("realAlpn = " + alpn).AtInfo().WriteToLog(sid)
 			}
-				labels := strings.Split(name, ".")
-				for i := range labels {
-					labels[i] = "*"
-					candidate := strings.Join(labels, ".")
-					if apfb[candidate] != nil {
-						name = candidate
-						break
+
+			if len(napfb) > 1 || napfb[""] == nil {
+				if napfb[name] == nil {
+					generic := "*"
+					if index := strings.IndexByte(name, '.'); index != -1 {
+						generic += name[index:]
+					}
+					if napfb[generic] != nil {
+						name = generic
 					}
 				}
-				if apfb[name] == nil {
+			}
+
+			if napfb[name] == nil {
 				name = ""
 			}
-				if apfb[name][alpn] == nil {
-					alpn = ""
+			apfb := napfb[name]
+			if apfb == nil {
+				return newError(`failed to find the default "name" config`).AtWarning()
 			}
 
+			if apfb[alpn] == nil {
+				alpn = ""
 			}
-			pfb := apfb[name][alpn]
+			pfb := apfb[alpn]
 			if pfb == nil {
 				return newError(`failed to find the default "alpn" config`).AtWarning()
 			}