[systemd-commits] src/timedate
Kay Sievers
kay at kemper.freedesktop.org
Sun Mar 16 11:39:07 PDT 2014
src/timedate/timedate-sntp.c | 178 +++++++++++++++++++++++++++++++++++--------
1 file changed, 147 insertions(+), 31 deletions(-)
New commits:
commit 7b41586761d6173cf6596b84a55d6b036662e068
Author: Kay Sievers <kay at vrfy.org>
Date: Sun Mar 16 17:45:06 2014 +0100
timedated: handle external system time changes
diff --git a/src/timedate/timedate-sntp.c b/src/timedate/timedate-sntp.c
index 861bcb1..98a2172 100644
--- a/src/timedate/timedate-sntp.c
+++ b/src/timedate/timedate-sntp.c
@@ -42,15 +42,19 @@
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
+#include <sys/timerfd.h>
#include <sys/timex.h>
#include <sys/socket.h>
+#include "missing.h"
#include "util.h"
#include "sparse-endian.h"
#include "log.h"
#include "sd-event.h"
#include "timedate-sntp.h"
+#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
+
#ifndef ADJ_SETOFFSET
#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
#endif
@@ -114,29 +118,42 @@ struct ntp_msg {
} _packed_;
struct SNTPContext {
+ /* peer */
sd_event_source *event_receive;
- sd_event_source *event_timer;
-
char *server;
struct sockaddr_in server_addr;
int server_socket;
uint64_t packet_count;
+ /* last sent packet */
struct timespec trans_time_mon;
struct timespec trans_time;
+ usec_t retry_interval;
bool pending;
+ /* poll timer */
+ sd_event_source *event_timer;
usec_t poll_interval;
+ bool poll_resync;
+ /* statistics data */
struct {
double offset;
double delay;
} samples[8];
unsigned int samples_idx;
double samples_jitter;
+
+ /* last change */
+ bool jumped;
+
+ /* watch for time changes */
+ sd_event_source *event_clock_watch;
+ int clock_watch_fd;
};
-static int sntp_arm_timer(SNTPContext *sntp);
+static int sntp_arm_timer(SNTPContext *sntp, usec_t next);
+static int sntp_clock_watch_setup(SNTPContext *sntp);
static double ntp_ts_to_d(const struct ntp_ts *ts) {
return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
@@ -197,19 +214,22 @@ static int sntp_send_request(SNTPContext *sntp) {
addr.sin_port = htobe16(123);
addr.sin_addr.s_addr = inet_addr(sntp->server);
len = sendto(sntp->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &addr, sizeof(addr));
- if (len < 0) {
- log_debug("Sending NTP request to %s failed: %m", sntp->server);
- return -errno;
- }
-
- sntp->pending = true;
-
- /* re-arm timer for next poll interval, in case the packet never arrives back */
- r = sntp_arm_timer(sntp);
+ if (len == sizeof(ntpmsg)) {
+ sntp->pending = true;
+ log_debug("Sent NTP request to: %s", sntp->server);
+ } else
+ log_info("Sending NTP request to %s failed: %m", sntp->server);
+
+ /* re-arm timer with incresing timeout, in case the packets never arrive back */
+ if (sntp->retry_interval > 0) {
+ if (sntp->retry_interval < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC)
+ sntp->retry_interval *= 2;
+ } else
+ sntp->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
+ r = sntp_arm_timer(sntp, sntp->retry_interval);
if (r < 0)
return r;
- log_debug("Sent NTP request to: %s", sntp->server);
return 0;
}
@@ -222,20 +242,20 @@ static int sntp_timer(sd_event_source *source, usec_t usec, void *userdata) {
return 0;
}
-static int sntp_arm_timer(SNTPContext *sntp) {
+static int sntp_arm_timer(SNTPContext *sntp, usec_t next) {
sd_event *e;
int r;
assert(sntp);
assert(sntp->event_receive);
- if (sntp->poll_interval <= 0) {
+ if (next == 0) {
sntp->event_timer = sd_event_source_unref(sntp->event_timer);
return 0;
}
if (sntp->event_timer) {
- r = sd_event_source_set_time(sntp->event_timer, now(CLOCK_MONOTONIC) + sntp->poll_interval);
+ r = sd_event_source_set_time(sntp->event_timer, now(CLOCK_MONOTONIC) + next);
if (r < 0)
return r;
@@ -243,13 +263,76 @@ static int sntp_arm_timer(SNTPContext *sntp) {
}
e = sd_event_source_get_event(sntp->event_receive);
- r = sd_event_add_monotonic(e, &sntp->event_timer, now(CLOCK_MONOTONIC) + sntp->poll_interval, 0, sntp_timer, sntp);
+ r = sd_event_add_monotonic(e, &sntp->event_timer, now(CLOCK_MONOTONIC) + next, 0, sntp_timer, sntp);
if (r < 0)
return r;
return 0;
}
+static int sntp_clock_watch(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+ SNTPContext *sntp = userdata;
+
+ assert(sntp);
+ assert(sntp->event_receive);
+
+ /* rearm timer */
+ sntp_clock_watch_setup(sntp);
+
+ /* skip our own jumps */
+ if (sntp->jumped) {
+ sntp->jumped = false;
+ return 0;
+ }
+
+ /* resync */
+ log_info("System time changed, resyncing.");
+ sntp->poll_resync = true;
+ sntp_send_request(sntp);
+
+ return 0;
+}
+
+/* wake up when the system time changes underneath us */
+static int sntp_clock_watch_setup(SNTPContext *sntp) {
+ struct itimerspec its = { .it_value.tv_sec = TIME_T_MAX };
+ _cleanup_close_ int fd = -1;
+ sd_event *e;
+ sd_event_source *source;
+ int r;
+
+ assert(sntp);
+ assert(sntp->event_receive);
+
+ fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+ if (fd < 0) {
+ log_error("Failed to create timerfd: %m");
+ return -errno;
+ }
+
+ if (timerfd_settime(fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) {
+ log_error("Failed to set up timerfd: %m");
+ return -errno;
+ }
+
+ e = sd_event_source_get_event(sntp->event_receive);
+ r = sd_event_add_io(e, &source, fd, EPOLLIN, sntp_clock_watch, sntp);
+ if (r < 0) {
+ log_error("Failed to create clock watch event source: %s", strerror(-r));
+ return r;
+ }
+
+ sd_event_source_unref(sntp->event_clock_watch);
+ sntp->event_clock_watch = source;
+
+ if (sntp->clock_watch_fd >= 0)
+ close(sntp->clock_watch_fd);
+ sntp->clock_watch_fd = fd;
+ fd = -1;
+
+ return 0;
+}
+
static int sntp_adjust_clock(SNTPContext *sntp, double offset, int leap_sec) {
struct timex tmx = {};
int r;
@@ -270,11 +353,12 @@ static int sntp_adjust_clock(SNTPContext *sntp, double offset, int leap_sec) {
tmx.status = STA_PLL;
tmx.offset = offset * 1000 * 1000;
tmx.constant = constant;
-
log_debug(" adjust (slew): %+f sec\n", (double)tmx.offset / USEC_PER_SEC);
} else {
tmx.modes = ADJ_SETOFFSET;
d_to_tv(offset, &tmx.time);
+
+ sntp->jumped = true;
log_debug(" adjust (jump): %+f sec\n", tv_to_d(&tmx.time));
}
@@ -320,10 +404,12 @@ static bool sntp_sample_spike_detection(SNTPContext *sntp, double offset, double
sntp->packet_count++;
/*
- * Spike detection; compare the difference between the
- * current offset to the previous offset and jitter.
+ * Spike detection; compare the difference between the current offset to
+ * the previous offset and jitter.
*/
- spike = sntp->packet_count > 2 && fabs(offset - sntp->samples[idx_cur].offset) > sntp->samples_jitter * 3;
+ spike = !sntp->poll_resync &&
+ sntp->packet_count > 2 &&
+ fabs(offset - sntp->samples[idx_cur].offset) > sntp->samples_jitter * 3;
/* calculate new jitter value from the RMS differences relative to the lowest delay sample */
for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(sntp->samples); i++)
@@ -340,6 +426,12 @@ static bool sntp_sample_spike_detection(SNTPContext *sntp, double offset, double
static void sntp_adjust_poll(SNTPContext *sntp, double offset, bool spike) {
double delta;
+ if (sntp->poll_resync) {
+ sntp->poll_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC;
+ sntp->poll_resync = false;
+ return;
+ }
+
if (spike) {
if (sntp->poll_interval > NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC)
sntp->poll_interval /= 2;
@@ -443,7 +535,6 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven
log_debug("Unexpected reply, ignoring");
return 0;
}
- sntp->pending = false;
/* check our "time cookie" (we just stored nanoseconds in the fraction field) */
if (be32toh(ntpmsg->origin_time.sec) != sntp->trans_time.tv_sec + OFFSET_1900_1970||
@@ -467,6 +558,10 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven
return -EINVAL;
}
+ /* valid packet */
+ sntp->pending = false;
+ sntp->retry_interval = 0;
+
/* announce leap seconds */
if (NTP_FIELD_LEAP(ntpmsg->field) & NTP_LEAP_PLUSSEC)
leap_sec = 1;
@@ -539,7 +634,7 @@ static int sntp_receive_response(sd_event_source *source, int fd, uint32_t reven
log_error("Failed to call clock_adjtime(): %m");
}
- r = sntp_arm_timer(sntp);
+ r = sntp_arm_timer(sntp, sntp->poll_interval);
if (r < 0)
return r;
@@ -575,27 +670,29 @@ void sntp_server_disconnect(SNTPContext *sntp) {
return;
sntp->event_timer = sd_event_source_unref(sntp->event_timer);
+
+ sntp->event_clock_watch = sd_event_source_unref(sntp->event_clock_watch);
+ if (sntp->clock_watch_fd > 0)
+ close(sntp->clock_watch_fd);
+ sntp->clock_watch_fd = -1;
+
sntp->event_receive = sd_event_source_unref(sntp->event_receive);
if (sntp->server_socket > 0)
close(sntp->server_socket);
sntp->server_socket = -1;
+
zero(sntp->server_addr);
free(sntp->server);
sntp->server = NULL;
}
-int sntp_new(SNTPContext **sntp, sd_event *e) {
- _cleanup_free_ SNTPContext *c;
+static int sntp_listen_setup(SNTPContext *sntp, sd_event *e) {
_cleanup_close_ int fd = -1;
struct sockaddr_in addr;
const int on = 1;
const int tos = IPTOS_LOWDELAY;
int r;
- c = new0(SNTPContext, 1);
- if (!c)
- return -ENOMEM;
-
fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (fd < 0)
return -errno;
@@ -614,13 +711,32 @@ int sntp_new(SNTPContext **sntp, sd_event *e) {
if (r < 0)
return -errno;
- r = sd_event_add_io(e, &c->event_receive, fd, EPOLLIN, sntp_receive_response, c);
+ r = sd_event_add_io(e, &sntp->event_receive, fd, EPOLLIN, sntp_receive_response, sntp);
if (r < 0)
return r;
- c->server_socket = fd;
+ sntp->server_socket = fd;
fd = -1;
+ return 0;
+}
+
+int sntp_new(SNTPContext **sntp, sd_event *e) {
+ _cleanup_free_ SNTPContext *c;
+ int r;
+
+ c = new0(SNTPContext, 1);
+ if (!c)
+ return -ENOMEM;
+
+ r = sntp_listen_setup(c, e);
+ if (r < 0)
+ return r;
+
+ r = sntp_clock_watch_setup(c);
+ if (r < 0)
+ return r;
+
*sntp = c;
c = NULL;
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