fix nil pointer panic in v2.5.3' :s5s

Author: threatexpert

apps/nc.go

@@ -34,7 +34,7 @@ import (
 )
 
 var (
-	VERSION = "v2.5.3"
+	VERSION = "v2.5.4"
 )
 
 type AppNetcatConfig struct {
@@ -325,16 +325,16 @@ func AppNetcatConfigByArgs(logWriter io.Writer, argv0 string, args []string) (*A
 	// 1. 初始化基本设置
 	firstInit(config)
 
-	// 2. 配置内置应用程序模式（例如http服务器，socks5）
-	configureAppMode(config)
-
-	// 3. 配置安全功能，如PSK和ACL
+	// 2. 配置安全功能，如PSK和ACL
 	err = configureSecurity(config)
 	if err != nil {
 		fmt.Fprintf(logWriter, "Security configuration failed: %v\n", err)
 		os.Exit(1)
 	}
 
+	// 3. 配置内置应用程序模式（例如http服务器，socks5）
+	configureAppMode(config)
+
 	if fs.NFlag() == 0 && fs.NArg() == 0 {
 		usage_less(logWriter, argv0)
 		os.Exit(1)
@@ -1982,6 +1982,9 @@ func preinitBuiltinAppConfig(ncconfig *AppNetcatConfig, commandline string) erro
 		ncconfig.app_s5s_Config, err = AppS5SConfigByArgs(ncconfig.LogWriter, args[1:])
 		if err == nil {
 			ncconfig.app_s5s_Config.AccessCtrl = ncconfig.accessControl
+			if ncconfig.app_s5s_Config.UpstreamClient != nil && ncconfig.accessControl != nil {
+				ncconfig.Logger.Printf(":s5s -x enabled: outbound ACL for target addresses is ignored; inbound ACL still applies.\n")
+			}
 		}
 	case ":s5c":
 		ncconfig.app_s5c_Config, err = AppS5CConfigByArgs(ncconfig.LogWriter, args[1:])

apps/proxyclient.go

@@ -156,20 +156,29 @@ func (c *DirectDialer) Listen(network, address string) (net.Listener, error) {
 
 // Dial 实现 ProxyClient 的拨号逻辑，委托给内部的 dialer
 func (c *ProxyClient) DialTimeout(network, address string, timeout time.Duration) (net.Conn, error) {
+	if c == nil {
+		return nil, fmt.Errorf("proxy client not initialized")
+	}
 	if c.Dialer == nil {
 		return nil, fmt.Errorf("proxy client not initialized, call NewProxyClient first")
 	}
 	return c.Dialer.DialTimeout(network, address, timeout)
 }
 
 func (c *ProxyClient) Listen(network, address string) (net.Listener, error) {
+	if c == nil {
+		return nil, fmt.Errorf("proxy client not initialized")
+	}
 	if c.Dialer == nil {
 		return nil, fmt.Errorf("proxy client not initialized")
 	}
 	return c.Dialer.Listen(network, address)
 }
 
 func (c *ProxyClient) SupportBIND() bool {
+	if c == nil {
+		return false
+	}
 	// 目前仅 SOCKS5 支持 BIND
 	return c.ProxyProt == "socks5"
 }

apps/proxyserver.go

@@ -27,7 +27,9 @@ func handleSocks5Proxy(conn net.Conn, keyingMaterial [32]byte, config *AppS5SCon
 		ServerIP:   config.ServerIP,
 		Localbind:  config.Localbind,
 		AccessCtrl: config.AccessCtrl,
-		Outbound:   config.UpstreamClient,
+	}
+	if config.UpstreamClient != nil {
+		s5config.Outbound = config.UpstreamClient
 	}
 	s5auth := &Socks5AuthConfig{
 		AuthenticateUser: nil,