summaryrefslogtreecommitdiff
path: root/src/timedate/timedate-sntp.c
diff options
context:
space:
mode:
authorKay Sievers <kay@vrfy.org>2014-03-31 04:00:04 +0200
committerKay Sievers <kay@vrfy.org>2014-03-31 04:09:39 +0200
commit42742bf1ce3a2a4fecb82df9d8adea57133ae33b (patch)
treec442ff9034a6b803107cdd0a528b4d14b4e1069e /src/timedate/timedate-sntp.c
parent2ad7561f9f658f8dee168a76654c7d918e2260c7 (diff)
timedated: adjust accuracy and slew values
Diffstat (limited to 'src/timedate/timedate-sntp.c')
-rw-r--r--src/timedate/timedate-sntp.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/src/timedate/timedate-sntp.c b/src/timedate/timedate-sntp.c
index e47a086567..b5d60c60af 100644
--- a/src/timedate/timedate-sntp.c
+++ b/src/timedate/timedate-sntp.c
@@ -59,24 +59,24 @@
#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
#endif
-/* Maximum delta in seconds which the system clock is gradually adjusted
- * to approach the network time. Deltas larger that this are set by letting
- * the system time jump. The maximum for adjtime is 500ms.
- */
-#define NTP_MAX_ADJUST 0.2
+/* expected accuracy of time synchronization; used to adjust the poll interval */
+#define NTP_ACCURACY_SEC 0.2
/*
- * "Define the required accuracy of the system clock, then calculate the
- * maximum timeout. Use the longest maximum timeout possible given the system
- * constraints to minimize time server aggregate load."
- *
* "A client MUST NOT under any conditions use a poll interval less
* than 15 seconds."
*/
-#define NTP_POLL_INTERVAL_MIN_SEC 16
+#define NTP_POLL_INTERVAL_MIN_SEC 32
#define NTP_POLL_INTERVAL_MAX_SEC 2048
-#define NTP_ACCURACY_SEC 0.1
+/*
+ * Maximum delta in seconds which the system clock is gradually adjusted
+ * (slew) to approach the network time. Deltas larger that this are set by
+ * letting the system time jump. The kernel's limit for adjtime is 0.5s.
+ */
+#define NTP_MAX_ADJUST 0.4
+
+/* NTP protocol, packet header */
#define NTP_LEAP_PLUSSEC 1
#define NTP_LEAP_MINUSSEC 2
#define NTP_LEAP_NOTINSYNC 3
@@ -666,7 +666,7 @@ int sntp_server_connect(SNTPContext *sntp, const char *server) {
sntp->server_addr.sin_family = AF_INET;
sntp->server_addr.sin_addr.s_addr = inet_addr(server);
- sntp->poll_interval_usec = 2 * NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
+ sntp->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
return sntp_send_request(sntp);
}