From 004986310d2a744f354f83489c3d215004f4f26a Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Wed, 11 Sep 2019 18:35:29 +0200
Subject: [PATCH] ntp: skip loop test if no server socket is open

If there is no socket that could receive a request from a client or
peer, we know that nothing can be synchronized to us and no loop is
possible.
---
 ntp_core.c           | 4 ++--
 ntp_io.c             | 8 ++++++++
 ntp_io.h             | 3 +++
 test/unit/ntp_core.c | 1 +
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/ntp_core.c b/ntp_core.c
index 7266e2e..4eb3674 100644
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -1474,9 +1474,9 @@ check_sync_loop(NCR_Instance inst, NTP_Packet *message, NTP_Local_Address *local
   NTP_Leap leap_status;
   uint32_t our_ref_id;
 
-  /* Check if our server may be enabled, i.e. a client or peer can actually
+  /* Check if a server socket is open, i.e. a client or peer can actually
      be synchronised to us */
-  if (REF_GetMode() != REF_ModeNormal)
+  if (!NIO_IsServerSocketOpen())
     return 1;
 
   /* Check if the source indicates that it is synchronised to our address
diff --git a/ntp_io.c b/ntp_io.c
index f947237..4d9699d 100644
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -329,6 +329,14 @@ NIO_IsServerSocket(int sock_fd)
 
 /* ================================================== */
 
+int
+NIO_IsServerSocketOpen(void)
+{
+  return server_sock_fd4 != INVALID_SOCK_FD || server_sock_fd6 != INVALID_SOCK_FD;
+}
+
+/* ================================================== */
+
 int
 NIO_IsServerConnectable(NTP_Remote_Address *remote_addr)
 {
diff --git a/ntp_io.h b/ntp_io.h
index 628f736..d52d56f 100644
--- a/ntp_io.h
+++ b/ntp_io.h
@@ -53,6 +53,9 @@ extern void NIO_CloseServerSocket(int sock_fd);
 /* Function to check if socket is a server socket */
 extern int NIO_IsServerSocket(int sock_fd);
 
+/* Function to check if a server socket is currently open */
+extern int NIO_IsServerSocketOpen(void);
+
 /* Function to check if client packets can be sent to a server */
 extern int NIO_IsServerConnectable(NTP_Remote_Address *remote_addr);
 
diff --git a/test/unit/ntp_core.c b/test/unit/ntp_core.c
index 18992ac..9cfff5f 100644
--- a/test/unit/ntp_core.c
+++ b/test/unit/ntp_core.c
@@ -39,6 +39,7 @@ static int req_length, res_length;
 #define NIO_OpenClientSocket(addr) ((addr)->ip_addr.family != IPADDR_UNSPEC ? 101 : 0)
 #define NIO_CloseClientSocket(fd) assert(fd == 101)
 #define NIO_IsServerSocket(fd) (fd == 100)
+#define NIO_IsServerSocketOpen() 1
 #define NIO_SendPacket(msg, to, from, len, process_tx) (memcpy(&req_buffer, msg, len), req_length = len, 1)
 #define SCH_AddTimeoutByDelay(delay, handler, arg) (1 ? 102 : (handler(arg), 1))
 #define SCH_AddTimeoutInClass(delay, separation, randomness, class, handler, arg) \