plugins: add configure support for overriding RTC fallback datetime

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

configure.ac

@@ -159,6 +159,10 @@ AC_ARG_WITH(plugin-path,
         AS_HELP_STRING([--with-plugin-path=DIR], [Search path for external plugins, default /usr/lib/finit/plugins:/usr/local/lib/finit/plugins]),
 	[plugin_path=$withval], [plugin_path=yes])
 
+AC_ARG_WITH(rtc-date,
+	AS_HELP_STRING([--with-rtc-date=DATE], [If RTC date/time is too old, restore to DATE, format "YYYY-MM-DD HH:MM", default "2000-01-01 00:00"]),
+	[rtc_date=$withval], [rtc_date=no])
+
 ### Enable features ###########################################################################
 
 # Create config.h from selected features and fallback defaults
@@ -242,6 +246,10 @@ AS_IF([test "x$with_random_seed" != "xno"], [
 	AC_EXPAND_DIR(random_path, "$random_seed")
 	AC_DEFINE_UNQUOTED(RANDOMSEED, "$random_path", [Improve random at boot by seeding it with sth from before.])])
 
+AS_IF([test "x$rtc_date" != "xno"], [
+	AC_DEFINE(RTC_TIMESTAMP_CUSTOM, "$rtc_date", [Custom RTC restore date, default: 2000-01-01 00:00])], [
+	rtc_date=""])
+
 AS_IF([test "x$with_keventd" != "xno"], [with_keventd=yes])
 
 AS_IF([test "x$with_sulogin" != "xno"], [with_sulogin=yes])
@@ -302,6 +310,10 @@ AC_DEFINE_UNQUOTED(SAMPLE_CONF, "$sample_conf", [Finit sameple.conf for initctl
 AS_IF([test "$heading" = ""],   [heading="<DEFAULT>"])
 AS_IF([test "$heading" = "no"], [heading="<NONE>"])
 
+RTC_DATE=$rtc_date
+AS_IF([test "$rtc_date" = ""],   [RTC_DATE="<DEFAULT>"])
+AS_IF([test "$rtc_date" = "no"], [RTC_DATE="<DEFAULT>"])
+
 # Generate all files
 AC_OUTPUT
 
@@ -326,6 +338,7 @@ cat <<EOF
 Behavior:
   Boot heading..........: $heading
   Plugins...............: $plugins
+  RTC restore date......: $RTC_DATE
 
 Optional features:
   Install doc/..........: $enable_doc

plugins/rtc.c

@@ -21,6 +21,8 @@
  * THE SOFTWARE.
  */
 
+#include "config.h"
+
 #include <time.h>
 #include <sys/ioctl.h>
 #include <linux/rtc.h>
@@ -35,7 +37,13 @@
 #include "plugin.h"
 
 /* Kernel RTC driver validates against this date for sanity check */
-#define RTC_TIMESTAMP_BEGIN_2000        946684800LL /* 2000-01-01 00:00:00 */
+#define RTC_TIMESTAMP_BEGIN_2000 "2000-01-01 00:00:00"
+#ifdef  RTC_TIMESTAMP_CUSTOM
+static char  *rtc_timestamp     = RTC_TIMESTAMP_CUSTOM;
+#else
+static char  *rtc_timestamp     = RTC_TIMESTAMP_BEGIN_2000;
+#endif
+static time_t rtc_date_fallback = 946684800LL;
 
 static void tz_set(char *tz, size_t len)
 {
@@ -99,10 +107,10 @@ static void rtc_save(void *arg)
 
 	tz_set(tz, sizeof(tz));
 	rc = gettimeofday(&tv, NULL);
-	if (rc < 0 || tv.tv_sec < RTC_TIMESTAMP_BEGIN_2000) {
+	if (rc < 0 || tv.tv_sec < rtc_date_fallback) {
 		print_desc(NULL, "System clock invalid, not saving to RTC");
 	invalid:
-		logit(LOG_ERR, "System clock invalid, before 2000-01-01 00:00, not saving to RTC");
+		logit(LOG_ERR, "System clock invalid, before %s, not saving to RTC", rtc_timestamp);
 		rc = 2;
 		goto out;
 	}
@@ -136,8 +144,10 @@ static void rtc_restore(void *arg)
 	}
 
 	fd = rtc_open();
-	if (fd < 0)
+	if (fd < 0) {
+		logit(LOG_NOTICE, "System has no RTC (missing driver?), skipping restore.");
 		return;
+	}
 
 	tz_set(tz, sizeof(tz));
 	if (ioctl(fd, RTC_RD_TIME, &tm) < 0) {
@@ -151,7 +161,7 @@ static void rtc_restore(void *arg)
 	invalid:
 		logit(LOG_ERR, "Failed restoring system clock from RTC.");
 		if (EINVAL == errno)
-			logit(LOG_ERR, "RTC time is too old (before 2000-01-01 00:00)");
+			logit(LOG_ERR, "RTC time is too old (before %s)", rtc_timestamp);
 		else if (ENOENT == errno)
 			logit(LOG_ERR, "RTC has no previously saved (valid) time.");
 		else
@@ -162,18 +172,18 @@ static void rtc_restore(void *arg)
 			goto out;
 
 		/* Attempt to set RTC to a sane value ... */
-		tv.tv_sec = RTC_TIMESTAMP_BEGIN_2000;
+		tv.tv_sec = rtc_date_fallback;
 		if (!gmtime_r(&tv.tv_sec, &tm))
 			goto out;
 
-		logit(LOG_NOTICE, "Resetting RTC to kernel default, 2000-01-01 00:00.");
+		logit(LOG_NOTICE, "Resetting RTC to kernel default, %s.", rtc_timestamp);
 		rc = 2;
 	}
 
 	print_desc(NULL, "Restoring system clock (UTC) from RTC");
 	tm.tm_isdst = -1; /* Use tzdata to figure it out, please. */
 	tv.tv_sec = mktime(&tm);
-	if (tv.tv_sec < RTC_TIMESTAMP_BEGIN_2000) {
+	if (tv.tv_sec < rtc_date_fallback) {
 		errno = EINVAL;
 		goto invalid;
 	}
@@ -199,6 +209,13 @@ static plugin_t plugin = {
 
 PLUGIN_INIT(plugin_init)
 {
+	struct tm tm = { 0 };
+
+	if (!strptime(rtc_timestamp, "%Y-%m-%d %H:%M", &tm))
+		rtc_date_fallback = mktime(&tm);
+	else
+		rtc_timestamp = RTC_TIMESTAMP_BEGIN_2000;
+
 	plugin_register(&plugin);
 }