issue: 3586273 Use XLIO_DEFERRED_CLOSE by default

For incoming sockets - no change.
For outgoing sockets - since outgoing sockets occupy a local port, we
should release it on the socket destructor to prevent race from another
socket to use the same port.
This race might cause XLIO to hold 2 sockets with the same RFS object at
the same time, and this is fatal (particularly for TCP).

Signed-off-by: Iftah Levi <iftahl@nvidia.com>

src/core/sock/sock-redirect.cpp

@@ -237,7 +237,7 @@ char *sprintf_sockaddr(char *buf, int buflen, const struct sockaddr *_addr, sock
 
 bool handle_close(int fd, bool cleanup, bool passthrough)
 {
-    bool to_close_now = true;
+    bool to_close_now = !safe_mce_sys().deferred_close;
     bool is_for_udp_pool = false;
 
     srdr_logfunc("Cleanup fd=%d cleanup=%d", fd, !!cleanup);
@@ -253,15 +253,12 @@ bool handle_close(int fd, bool cleanup, bool passthrough)
         sockinfo *sockfd = fd_collection_get_sockfd(fd);
         if (sockfd) {
             // Don't call close(2) for objects without a shadow socket (TCP incoming sockets).
-            to_close_now = !passthrough && sockfd->is_shadow_socket_present();
+            to_close_now &= !passthrough && sockfd->is_shadow_socket_present();
 #if defined(DEFINED_NGINX)
             // Save this value before pointer is destructed
             is_for_udp_pool = sockfd->m_is_for_socket_pool;
 #endif
             g_p_fd_collection->del_sockfd(fd, is_for_udp_pool);
-            if (safe_mce_sys().deferred_close) {
-                to_close_now = false;
-            }
         }
         if (fd_collection_get_epfd(fd)) {
             g_p_fd_collection->del_epfd(fd, cleanup);
@@ -270,7 +267,7 @@ bool handle_close(int fd, bool cleanup, bool passthrough)
 #if defined(DEFINED_NGINX)
         if (g_p_app && g_p_app->type == APP_NGINX && is_for_udp_pool) {
             g_p_fd_collection->push_socket_pool(sockfd);
-            to_close_now = false;
+            return false;
         }
 #else
         NOT_IN_USE(is_for_udp_pool);

src/core/util/sys_vars.h

@@ -872,7 +872,7 @@ extern mce_sys_var &safe_mce_sys();
 #endif /* DEFINED_UTLS */
 
 #define MCE_DEFAULT_LRO                            (option_3::AUTO)
-#define MCE_DEFAULT_DEFERRED_CLOSE                 (false)
+#define MCE_DEFAULT_DEFERRED_CLOSE                 (true)
 #define MCE_DEFAULT_TCP_ABORT_ON_CLOSE             (false)
 #define MCE_DEFAULT_RX_POLL_ON_TX_TCP              (false)
 #define MCE_DEFAULT_TRIGGER_DUMMY_SEND_GETSOCKNAME (false)