ntp plugin: Unify casting to gauge_t.

Also add note about STA_NANO.

Issue: #1314.

diff --git a/src/ntpd.c b/src/ntpd.c
index 8e00734..f192a82 100644 (file)
--- a/src/ntpd.c
+++ b/src/ntpd.c
@@ -304,7 +304,7 @@ static int ntpd_config (const char *key, const char *value)
        return (0);
 }
 
-static void ntpd_submit (char *type, char *type_inst, double value)
+static void ntpd_submit (char *type, char *type_inst, gauge_t value)
 {
        value_t values[1];
        value_list_t vl = VALUE_LIST_INIT;
@@ -326,7 +326,7 @@ static void ntpd_submit (char *type, char *type_inst, double value)
  * sets the LSB based on whether the peer was reachable. If the LSB is zero,
  * the values are out of date. */
 static void ntpd_submit_reach (char *type, char *type_inst, uint8_t reach,
-               double value)
+               gauge_t value)
 {
        if (!(reach & 1))
                value = NAN;
@@ -899,9 +899,18 @@ static int ntpd_read (void)
        int                       ps_num;
        int                       ps_size;
 
+       gauge_t offset_loop;
+       gauge_t freq_loop;
+       gauge_t offset_error;
+
        int status;
        int i;
-       double tscale = 1e-6;
+
+       /* On Linux, if the STA_NANO bit is set in ik->status, then ik->offset
+        * is is nanoseconds, otherwise it's microseconds.
+        * TODO(octo): STA_NANO is defined in the Linux specific <sys/timex.h> header. */
+       double scale_loop  = 1e-6;
+       double scale_error = 1e-6;
 
        ik      = NULL;
        ik_num  = 0;
@@ -925,18 +934,19 @@ static int ntpd_read (void)
        }
 
        /* kerninfo -> estimated error */
+       offset_loop  = scale_loop * ((gauge_t) ntohl (ik->offset));
+       freq_loop    = ntpd_read_fp (ik->freq);
+       offset_error = scale_error * ((gauge_t) ntohl (ik->esterror));
 
        DEBUG ("info_kernel:\n"
-                       "  pll offset    = %.8f\n"
-                       "  pll frequency = %.8f\n" /* drift compensation */
-                       "  est error     = %.8f\n",
-                       (int32_t)ntohl(ik->offset) * tscale,
-                       ntpd_read_fp (ik->freq),
-                       (u_long)ntohl(ik->esterror) * 1e-6);
-
-       ntpd_submit ("frequency_offset", "loop",  ntpd_read_fp (ik->freq));
-       ntpd_submit ("time_offset",      "loop",  (int32_t)ntohl(ik->offset) * tscale);
-       ntpd_submit ("time_offset",      "error", (u_long)ntohl(ik->esterror) * 1e-6);
+                       "  pll offset    = %.8g\n"
+                       "  pll frequency = %.8g\n" /* drift compensation */
+                       "  est error     = %.8g\n",
+                       offset_loop, freq_loop, offset_error);
+
+       ntpd_submit ("frequency_offset", "loop",  freq_loop);
+       ntpd_submit ("time_offset",      "loop",  offset_loop);
+       ntpd_submit ("time_offset",      "error", offset_error);
 
        free (ik);
        ik = NULL;