From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Tue, 16 May 2023 13:11:22 +0000 (+0200)
Subject: ntp: reset polling interval when replacing sources
X-Git-Tag: 4.4-pre2~28
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ba42cee45a610b15dd7fd24bb88170ee51ee830;p=thirdparty%2Fchrony.git

ntp: reset polling interval when replacing sources

Set the polling interval to minpoll when changing address of a source,
but only if it is reachable to avoid increasing load on server or
network in case that is the reason for the source being unreachable.

This shortens the time needed to replace a falseticker or
unsynchronized source with a selectable source.
---

diff --git a/ntp_core.c b/ntp_core.c
index 4e2289a3..8ce9ed9b 100644
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -833,6 +833,12 @@ NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr, int
     inst->local_addr.sock_fd = NIO_OpenServerSocket(remote_addr);
   }
 
+  /* Reset the polling interval only if the source wasn't unreachable to
+     avoid increasing server/network load in case that is what caused
+     the source to be unreachable */
+  if (SRC_IsReachable(inst->source))
+    NCR_ResetPoll(inst);
+
   /* Update the reference ID and reset the source/sourcestats instances */
   SRC_SetRefid(inst->source, UTI_IPToRefid(&remote_addr->ip_addr),
                &inst->remote_addr.ip_addr);
diff --git a/test/simulation/137-pool b/test/simulation/137-pool
index de8d77d1..41c65d22 100755
--- a/test/simulation/137-pool
+++ b/test/simulation/137-pool
@@ -46,4 +46,23 @@ check_sync || test_fail
 check_file_messages "20.*192.168.123.*" 15 17 measurements.log || test_fail
 rm -f tmp/measurements.log
 
+servers=6
+falsetickers=2
+client_server_conf="pool nodes-1-2-3-4-5-6.net1.clk maxsources 5 polltarget 1 iburst"
+wander=1e-12
+jitter=1e-6
+min_sync_time=7
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_log_messages "Detected falseticker" 2 10 || test_fail
+check_log_messages "Source 192.168.123.. replaced with" 1 1 || test_fail
+check_file_messages "20.*192.168.123.* 11.1   6  6 " 15 17 measurements.log || test_fail
+check_file_messages "20.*00:01:.. 192.168.123.* 11.1   6  6 " 1 1 measurements.log || test_fail
+rm -f tmp/measurements.log
+
 test_pass