nghttpx: Use SOCK_NONBLOCK and SOCK_CLOEXEC flag in socketpair to avoid race

src/shrpx_http2_session.cc

@@ -193,15 +193,13 @@ int Http2Session::init_notification()
 {
   int rv;
   int sockpair[2];
-  rv = socketpair(AF_UNIX, SOCK_STREAM, 0, sockpair);
+  rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0,
+                  sockpair);
   if(rv == -1) {
     SSLOG(FATAL, this) << "socketpair() failed: errno=" << errno;
     return -1;
   }
-  for(int i = 0; i < 2; ++i) {
-    evutil_make_socket_nonblocking(sockpair[i]);
-    evutil_make_socket_closeonexec(sockpair[i]);
-  }
+
   wrbev_ = bufferevent_socket_new(evbase_, sockpair[0],
                                   BEV_OPT_CLOSE_ON_FREE|
                                   BEV_OPT_DEFER_CALLBACKS);

src/shrpx_listen_handler.cc

@@ -103,17 +103,13 @@ void ListenHandler::create_worker_thread(size_t num)
   for(size_t i = 0; i < num; ++i) {
     int rv;
     auto info = util::make_unique<WorkerInfo>();
-    rv = socketpair(AF_UNIX, SOCK_STREAM, 0, info->sv);
+    rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0,
+                    info->sv);
     if(rv == -1) {
       LLOG(ERROR, this) << "socketpair() failed: errno=" << errno;
       continue;
     }
 
-    for(int j = 0; j < 2; ++j) {
-      evutil_make_socket_nonblocking(info->sv[j]);
-      evutil_make_socket_closeonexec(info->sv[j]);
-    }
-
     info->sv_ssl_ctx = sv_ssl_ctx_;
     info->cl_ssl_ctx = cl_ssl_ctx_;