sys: add generic timex driver

This is based on sys_linux.c and wrap_adjtimex.c. It's intended for all
systems that support the adjtimex() or ntp_adjtime() system call. The
driver functions can be replaced with extended system-specific versions
(e.g. to control the frequency with the tick field on Linux).

diff --git a/logging.h b/logging.h
index 00bc4240dce90ce2db57374f60e8919fe28b23b2..7c89bb745dc50c32e7714cc23b9659ec3ab5c909 100644 (file)
--- a/logging.h
+++ b/logging.h
@@ -99,6 +99,7 @@ typedef enum {
   LOGF_SysNetBSD,
   LOGF_SysSolaris,
   LOGF_SysSunOS,
+  LOGF_SysTimex,
   LOGF_SysWinnt,
   LOGF_TempComp,
   LOGF_RtcLinux,

diff --git a/sys_timex.c b/sys_timex.c
new file mode 100644 (file)
index 0000000..05afc92
--- /dev/null
+++ b/sys_timex.c
@@ -0,0 +1,230 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Richard P. Curnow  1997-2003
+ * Copyright (C) Miroslav Lichvar  2009-2012, 2014-2015
+ * 
+ * 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 "sys_generic.h"
+#include "sys_timex.h"
+#include "logging.h"
+
+#ifdef LINUX
+#define NTP_ADJTIME adjtimex
+#define NTP_ADJTIME_NAME "adjtimex"
+#else
+#define NTP_ADJTIME ntp_adjtime
+#define NTP_ADJTIME_NAME "ntp_adjtime"
+#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 status;
+
+/* ================================================== */
+
+static double
+read_frequency(void)
+{
+  struct timex txc;
+
+  txc.modes = 0;
+
+  SYS_Timex_Adjust(&txc, 0);
+
+  return txc.freq / -FREQ_SCALE;
+}
+
+/* ================================================== */
+
+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 txc.freq / -FREQ_SCALE;
+}
+
+/* ================================================== */
+
+static void
+set_leap(int leap)
+{
+  struct timex txc;
+  int applied;
+
+  applied = 0;
+  if (!leap) {
+    txc.modes = 0;
+    if (SYS_Timex_Adjust(&txc, 1) == TIME_WAIT)
+      applied = 1;
+  }
+
+  status &= ~(STA_INS | STA_DEL);
+
+  if (leap > 0)
+    status |= STA_INS;
+  else if (leap < 0)
+    status |= STA_DEL;
+
+  txc.modes = MOD_STATUS;
+  txc.status = status;
+
+  SYS_Timex_Adjust(&txc, 0);
+
+  LOG(LOGS_INFO, LOGF_SysTimex, "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)
+    status &= ~STA_UNSYNC;
+  else
+    status |= STA_UNSYNC;
+
+  txc.modes = MOD_STATUS | MOD_ESTERROR | MOD_MAXERROR;
+  txc.status = status;
+  txc.esterror = est_error * 1.0e6;
+  txc.maxerror = max_error * 1.0e6;
+
+  SYS_Timex_Adjust(&txc, 1);
+}
+
+/* ================================================== */
+
+static void
+initialise_timex(void)
+{
+  struct timex txc;
+
+  status = STA_UNSYNC;
+
+  /* Reset PLL offset */
+  txc.modes = MOD_OFFSET | MOD_STATUS;
+  txc.status = STA_PLL | status;
+  txc.offset = 0;
+  SYS_Timex_Adjust(&txc, 0);
+
+  /* Turn PLL off */
+  txc.modes = MOD_STATUS;
+  txc.status = status;
+  SYS_Timex_Adjust(&txc, 0);
+}
+
+/* ================================================== */
+
+void
+SYS_Timex_Initialise(void)
+{
+  SYS_Timex_InitialiseWithFunctions(MAX_FREQ, 1.0 / MIN_TICK_RATE, NULL, 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)
+{
+  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, 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;
+
+  state = NTP_ADJTIME(txc);
+
+  if (state < 0) {
+    if (!ignore_error)
+      LOG_FATAL(LOGF_SysTimex, NTP_ADJTIME_NAME"(0x%x) failed : %s",
+                txc->modes, strerror(errno));
+    else
+      DEBUG_LOG(LOGF_SysTimex, NTP_ADJTIME_NAME"(0x%x) failed : %s",
+                txc->modes, strerror(errno));
+  }
+
+  return state;
+}

diff --git a/sys_timex.h b/sys_timex.h
new file mode 100644 (file)
index 0000000..9f8544b
--- /dev/null
+++ b/sys_timex.h
@@ -0,0 +1,47 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2015
+ * 
+ * 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.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header file for a driver based on the adjtimex()/ntp_adjtime() function
+  */
+
+#ifndef GOT_SYS_TIMEX_H
+#define GOT_SYS_TIMEX_H
+
+#include <sys/timex.h>
+
+#include "localp.h"
+
+extern void SYS_Timex_Initialise(void);
+
+/* Initialise with some driver functions replaced with special versions */
+extern 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);
+
+extern void SYS_Timex_Finalise(void);
+
+/* Wrapper for adjtimex()/ntp_adjtime() */
+extern int SYS_Timex_Adjust(struct timex *txc, int ignore_error);
+
+#endif  /* GOT_SYS_GENERIC_H */