Fix VPN apis for Android 4.x

src/local.c

@@ -264,11 +264,18 @@ static void server_recv_cb(EV_P_ ev_io *w, int revents)
             if (!remote->send_ctx->connected) {
 #ifdef ANDROID
                 if (vpn) {
-                    if (protect_socket(remote->fd) == -1) {
-                        ERROR("protect_socket");
-                        close_and_free_remote(EV_A_ remote);
-                        close_and_free_server(EV_A_ server);
-                        return;
+                    int not_protect = 0;
+                    if (remote->addr.ss_family == AF_INET) {
+                        struct sockaddr_in *s = (struct sockaddr_in *)&remote->addr;
+                        if (s->sin_addr.s_addr == inet_addr("127.0.0.1")) not_protect = 1;
+                    }
+                    if (!not_protect) {
+                        if (protect_socket(remote->fd) == -1) {
+                            ERROR("protect_socket");
+                            close_and_free_remote(EV_A_ remote);
+                            close_and_free_server(EV_A_ server);
+                            return;
+                        }
                     }
                 }
 #endif

src/tunnel.c

@@ -633,10 +633,17 @@ static void accept_cb(EV_P_ ev_io *w, int revents)
 
 #ifdef ANDROID
     if (vpn) {
-        if (protect_socket(remotefd) == -1) {
-            ERROR("protect_socket");
-            close(remotefd);
-            return;
+        int not_protect = 0;
+        if (remote_addr->sa_family == AF_INET) {
+            struct sockaddr_in *s = (struct sockaddr_in *)remote_addr;
+            if (s->sin_addr.s_addr == inet_addr("127.0.0.1")) not_protect = 1;
+        }
+        if (!not_protect) {
+            if (protect_socket(remotefd) == -1) {
+                ERROR("protect_socket");
+                close(remotefd);
+                return;
+            }
         }
     }
 #endif