1 files changed, 276 insertions, 0 deletions
diff --git a/sys_timex.c b/sys_timex.c
new file mode 100644
index 0000000..0ee6c8e
--- /dev/null
+++ b/sys_timex.c
@@ -0,0 +1,276 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Richard P. Curnow  1997-2003
+ * Copyright (C) Miroslav Lichvar  2009-2012, 2014-2015, 2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Driver for systems that implement the adjtimex()/ntp_adjtime() system call
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "conf.h"
+#include "privops.h"
+#include "sys_generic.h"
+#include "sys_timex.h"
+#include "logging.h"
+
+#ifdef PRIVOPS_ADJUSTTIMEX
+#define NTP_ADJTIME PRV_AdjustTimex
+#define NTP_ADJTIME_NAME "ntp_adjtime"
+#else
+#ifdef LINUX
+#define NTP_ADJTIME adjtimex
+#define NTP_ADJTIME_NAME "adjtimex"
+#else
+#define NTP_ADJTIME ntp_adjtime
+#define NTP_ADJTIME_NAME "ntp_adjtime"
+#endif
+#endif
+
+/* Maximum frequency offset accepted by the kernel (in ppm) */
+#define MAX_FREQ 500.0
+
+/* Frequency scale to convert from ppm to the timex freq */
+#define FREQ_SCALE (double)(1 << 16)
+
+/* Threshold for the timex maxerror when the kernel sets the UNSYNC flag */
+#define MAX_SYNC_ERROR 16.0
+
+/* Minimum assumed rate at which the kernel updates the clock frequency */
+#define MIN_TICK_RATE 100
+
+/* Saved timex status */
+static int sys_status;
+
+/* Saved TAI-UTC offset */
+static int sys_tai_offset;
+
+/* ================================================== */
+
+static double
+convert_timex_frequency(const struct timex *txc)
+{
+  double freq_ppm;
+
+  freq_ppm = txc->freq / FREQ_SCALE;
+
+  return -freq_ppm;
+}
+
+/* ================================================== */
+
+static double
+read_frequency(void)
+{
+  struct timex txc;
+
+  txc.modes = 0;
+
+  SYS_Timex_Adjust(&txc, 0);
+
+  return convert_timex_frequency(&txc);
+}
+
+/* ================================================== */
+
+static double
+set_frequency(double freq_ppm)
+{
+  struct timex txc;
+
+  txc.modes = MOD_FREQUENCY;
+  txc.freq = freq_ppm * -FREQ_SCALE;
+
+  SYS_Timex_Adjust(&txc, 0);
+
+  return convert_timex_frequency(&txc);
+}
+
+/* ================================================== */
+
+static void
+set_leap(int leap, int tai_offset)
+{
+  struct timex txc;
+  int applied, prev_status;
+
+  txc.modes = 0;
+  applied = SYS_Timex_Adjust(&txc, 0) == TIME_WAIT;
+
+  prev_status = sys_status;
+  sys_status &= ~(STA_INS | STA_DEL);
+
+  if (leap > 0)
+    sys_status |= STA_INS;
+  else if (leap < 0)
+    sys_status |= STA_DEL;
+
+  txc.modes = MOD_STATUS;
+  txc.status = sys_status;
+
+#ifdef MOD_TAI
+  if (tai_offset) {
+    txc.modes |= MOD_TAI;
+    txc.constant = tai_offset;
+
+    if (applied && !(sys_status & (STA_INS | STA_DEL)))
+      sys_tai_offset += prev_status & STA_INS ? 1 : -1;
+
+    if (sys_tai_offset != tai_offset) {
+      sys_tai_offset = tai_offset;
+      LOG(LOGS_INFO, "System clock TAI offset set to %d seconds", tai_offset);
+    }
+  }
+#endif
+
+  SYS_Timex_Adjust(&txc, 0);
+
+  if (prev_status != sys_status) {
+    LOG(LOGS_INFO, "System clock status %s leap second",
+        leap ? (leap > 0 ? "set to insert" : "set to delete") :
+        (applied ? "reset after" : "set to not insert/delete"));
+  }
+}
+
+/* ================================================== */
+
+static void
+set_sync_status(int synchronised, double est_error, double max_error)
+{
+  struct timex txc;
+
+  if (synchronised) {
+    if (est_error > MAX_SYNC_ERROR)
+      est_error = MAX_SYNC_ERROR;
+    if (max_error >= MAX_SYNC_ERROR) {
+      max_error = MAX_SYNC_ERROR;
+      synchronised = 0;
+    }
+  } else {
+    est_error = max_error = MAX_SYNC_ERROR;
+  }
+
+#ifdef LINUX
+  /* On Linux clear the UNSYNC flag only if rtcsync is enabled */
+  if (!CNF_GetRtcSync())
+    synchronised = 0;
+#endif
+
+  if (synchronised)
+    sys_status &= ~STA_UNSYNC;
+  else
+    sys_status |= STA_UNSYNC;
+
+  txc.modes = MOD_STATUS | MOD_ESTERROR | MOD_MAXERROR;
+  txc.status = sys_status;
+  txc.esterror = est_error * 1.0e6;
+  txc.maxerror = max_error * 1.0e6;
+
+  if (SYS_Timex_Adjust(&txc, 1) < 0)
+    ;
+}
+
+/* ================================================== */
+
+static void
+initialise_timex(void)
+{
+  struct timex txc;
+
+  sys_status = STA_UNSYNC;
+  sys_tai_offset = 0;
+
+  /* Reset PLL offset */
+  txc.modes = MOD_OFFSET | MOD_STATUS;
+  txc.status = STA_PLL | sys_status;
+  txc.offset = 0;
+  SYS_Timex_Adjust(&txc, 0);
+
+  /* Turn PLL off */
+  txc.modes = MOD_STATUS;
+  txc.status = sys_status;
+  SYS_Timex_Adjust(&txc, 0);
+}
+
+/* ================================================== */
+
+void
+SYS_Timex_Initialise(void)
+{
+  SYS_Timex_InitialiseWithFunctions(MAX_FREQ, 1.0 / MIN_TICK_RATE, NULL, NULL, NULL,
+                                    0.0, 0.0, NULL, NULL);
+}
+
+/* ================================================== */
+
+void
+SYS_Timex_InitialiseWithFunctions(double max_set_freq_ppm, double max_set_freq_delay,
+                                  lcl_ReadFrequencyDriver sys_read_freq,
+                                  lcl_SetFrequencyDriver sys_set_freq,
+                                  lcl_ApplyStepOffsetDriver sys_apply_step_offset,
+                                  double min_fastslew_offset, double max_fastslew_rate,
+                                  lcl_AccrueOffsetDriver sys_accrue_offset,
+                                  lcl_OffsetCorrectionDriver sys_get_offset_correction)
+{
+  initialise_timex();
+
+  SYS_Generic_CompleteFreqDriver(max_set_freq_ppm, max_set_freq_delay,
+                                 sys_read_freq ? sys_read_freq : read_frequency,
+                                 sys_set_freq ? sys_set_freq : set_frequency,
+                                 sys_apply_step_offset,
+                                 min_fastslew_offset, max_fastslew_rate,
+                                 sys_accrue_offset, sys_get_offset_correction,
+                                 set_leap, set_sync_status);
+}
+
+/* ================================================== */
+
+void
+SYS_Timex_Finalise(void)
+{
+  SYS_Generic_Finalise();
+}
+
+/* ================================================== */
+
+int
+SYS_Timex_Adjust(struct timex *txc, int ignore_error)
+{
+  int state;
+
+#ifdef SOLARIS
+  /* The kernel seems to check the constant even when it's not being set */
+  if (!(txc->modes & MOD_TIMECONST))
+    txc->constant = 10;
+#endif
+
+  state = NTP_ADJTIME(txc);
+
+  if (state < 0) {
+    LOG(ignore_error ? LOGS_DEBUG : LOGS_FATAL,
+        NTP_ADJTIME_NAME"(0x%x) failed : %s", txc->modes, strerror(errno));
+  }
+
+  return state;
+}