From 76bed76289575ba1640c02d370ae5304ef8c5fe2 Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Mon, 21 May 2018 16:27:43 +0200
Subject: [PATCH] ntp: enable non-blocking mode on server sockets

Avoid blocking in sendmsg() due to a full send buffer.
---
 ntp_io.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ntp_io.c b/ntp_io.c
index 5c8c47a..3a3398a 100644
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -142,6 +142,10 @@ prepare_socket(int family, int port_number, int client_only)
   /* Close on exec */
   UTI_FdSetCloexec(sock_fd);
 
+  /* Enable non-blocking mode on server sockets */
+  if (!client_only && fcntl(sock_fd, F_SETFL, O_NONBLOCK))
+    DEBUG_LOG("Could not set O_NONBLOCK : %s", strerror(errno));
+
   /* Prepare local address */
   memset(&my_addr, 0, sizeof (my_addr));
   my_addr_len = 0;