This patch adds support for the leapfile in the generic pps source.
Such implementations prevents situtation when TAI offset is not set in the
system (which is true when there is no NTP daemon running that sets it) from
setting the UTC time in the disciplined PHC.
Leapfile and lstab will only be used when the tai offset read from system is 0.
Signed-off-by: Maciek Machnikowski <mac...@machnikowski.net>
Reviewed-by: Jacob Keller <jacob.e.kel...@intel.com>
---
ts2phc_generic_pps_source.c | 83 +++++++++++++++++++++++++++++++++----
1 file changed, 76 insertions(+), 7 deletions(-)
diff --git a/ts2phc_generic_pps_source.c b/ts2phc_generic_pps_source.c
index 6842d8e..d503aac 100644
--- a/ts2phc_generic_pps_source.c
+++ b/ts2phc_generic_pps_source.c
@@ -6,6 +6,7 @@
#include <stdlib.h>
#include <time.h>
+#include "lstab.h"
#include "missing.h"
#include "print.h"
#include "ts2phc_generic_pps_source.h"
@@ -14,15 +15,38 @@
struct ts2phc_generic_pps_source {
struct ts2phc_pps_source pps_source;
+ struct lstab *lstab;
};
static void ts2phc_generic_pps_source_destroy(struct ts2phc_pps_source *src)
{
struct ts2phc_generic_pps_source *s =
container_of(src, struct ts2phc_generic_pps_source, pps_source);
+
+ if (s->lstab) {
+ lstab_destroy(s->lstab);
+ }
+
free(s);
}
+static int get_ntx(struct timex *ntx)
+{
+ int code;
+
+ if (!ntx)
+ return -1;
+
+ memset(ntx, 0, sizeof(*ntx));
+ ntx->modes = ADJ_NANO;
+ code = adjtimex(ntx);
+ if (code == -1) {
+ pr_err("adjtimex failed: %m");
+ return -1;
+ }
+ return 0;
+}
+
/*
* Returns the time on the PPS source device at which the most recent
* PPS event was generated. This implementation assumes that the
@@ -31,17 +55,44 @@ static void ts2phc_generic_pps_source_destroy(struct
ts2phc_pps_source *src)
static int ts2phc_generic_pps_source_getppstime(struct ts2phc_pps_source *src,
struct timespec *ts)
{
+ struct ts2phc_generic_pps_source *s =
+ container_of(src, struct ts2phc_generic_pps_source, pps_source);
+ enum lstab_result result;
+ int64_t utc_time;
struct timex ntx;
- int code;
+ int tai_offset;
- memset(&ntx, 0, sizeof(ntx));
- ntx.modes = ADJ_NANO;
- code = adjtimex(&ntx);
- if (code == -1) {
- pr_err("adjtimex failed: %m");
+ if (get_ntx(&ntx)) {
return -1;
}
- ts->tv_sec = ntx.time.tv_sec + ntx.tai;
+
+ tai_offset = ntx.tai;
+
+ /* When TAI offset is not set in system - try to get it from leapfile */
+ if (tai_offset == 0) {
+ if (!s->lstab) {
+ return -1;
+ }
+
+ utc_time = ntx.time.tv_sec;
+ result = lstab_utc2tai(s->lstab, utc_time, &tai_offset);
+
+ switch (result) {
+ case LSTAB_OK:
+ break;
+ case LSTAB_UNKNOWN:
+ pr_err("Unable to find utc time in leap second table");
+ return -1;
+ case LSTAB_EXPIRED:
+ pr_err("UTC time is past leap second table expiry
date");
+ return -1;
+ case LSTAB_AMBIGUOUS:
+ pr_err("UTC time stamp is ambiguous");
+ return -1;
+ }
+ }
+
+ ts->tv_sec = ntx.time.tv_sec + tai_offset;
ts->tv_nsec = ntx.time.tv_usec;
return 0;
@@ -51,11 +102,29 @@ struct ts2phc_pps_source
*ts2phc_generic_pps_source_create(struct ts2phc_private
const char *dev)
{
struct ts2phc_generic_pps_source *src;
+ const char *leapfile;
+ struct timex ntx;
+
+ if (get_ntx(&ntx)) {
+ return NULL;
+ }
src = calloc(1, sizeof(*src));
if (!src) {
return NULL;
}
+
+ if (ntx.tai == 0) {
+ pr_err("UTC-TAI offset not set in system! Trying to revert to
leapfile");
+
+ leapfile = config_get_string(priv->cfg, NULL, "leapfile");
+ src->lstab = lstab_create(leapfile);
+ if (!src->lstab) {
+ free(src);
+ return NULL;
+ }
+ }
+
src->pps_source.destroy = ts2phc_generic_pps_source_destroy;
src->pps_source.getppstime = ts2phc_generic_pps_source_getppstime;
--
2.34.1
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