Inherit non-blocking status when accepting on most platforms

When accept() is used, socket non-blocking flag is inherited from listen
socket almost on all platforms (except Linux kernel).
Actually modern platforms use accept4() so this change is mostly for W32.

2 files changed, 15 insertions, 3 deletions

diff --git a/src/microhttpd/daemon.c b/src/microhttpd/daemon.c
index 231ac57f..c0278246 100644
--- a/src/microhttpd/daemon.c
+++ b/src/microhttpd/daemon.c
@@ -3550,7 +3550,11 @@ MHD_accept_connection (struct MHD_Daemon *daemon)
   s = accept (fd,
               addr,
               &addrlen);
+#ifdef MHD_ACCEPT_INHERIT_NONBLOCK
+  sk_nonbl = daemon->listen_nonblk;
+#else  /* ! MHD_ACCEPT_INHERIT_NONBLOCK */
   sk_nonbl = false;
+#endif /* ! MHD_ACCEPT_INHERIT_NONBLOCK */
 #ifndef MHD_WINSOCK_SOCKETS
   sk_spipe_supprs = false;
 #else  /* MHD_WINSOCK_SOCKETS */
@@ -3615,15 +3619,17 @@ MHD_accept_connection (struct MHD_Daemon *daemon)
     }
     return MHD_NO;
   }
-#if ! defined(USE_ACCEPT4) || ! defined(HAVE_SOCK_NONBLOCK)
-  if (! MHD_socket_nonblocking_ (s))
+
+  if (! sk_nonbl && ! MHD_socket_nonblocking_ (s))
   {
 #ifdef HAVE_MESSAGES
     MHD_DLOG (daemon,
               _ ("Failed to set nonblocking mode on incoming connection " \
                  "socket: %s\n"),
               MHD_socket_last_strerr_ ());
-#endif
+#else  /* ! HAVE_MESSAGES */
+    (void) 0; /* Mute compiler warning */
+#endif /* ! HAVE_MESSAGES */
   }
   else
     sk_nonbl = true;
diff --git a/src/microhttpd/mhd_sockets.h b/src/microhttpd/mhd_sockets.h
index 56ea64db..18f831a9 100644
--- a/src/microhttpd/mhd_sockets.h
+++ b/src/microhttpd/mhd_sockets.h
@@ -199,6 +199,12 @@ typedef SOCKET MHD_socket;
 #  define USE_ACCEPT4 1
 #endif
 
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || \
+  defined(MHD_WINSOCK_SOCKETS) || defined(__MACH__) || defined(__sun)
+/* Most of OSes inherit nonblocking setting from the listen socket */
+#define MHD_ACCEPT_INHERIT_NONBLOCK 1
+#endif
+
 #if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
 #  define USE_EPOLL_CREATE1 1
 #endif /* HAVE_EPOLL_CREATE1 && EPOLL_CLOEXEC */