Rename hwclock.so plugin to rtc.so since it's now stand-alone

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

plugins/rtc.c

@@ -0,0 +1,160 @@
+/* Save and restore RTC using hwclock
+ *
+ * Copyright (c) 2012-2019  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <time.h>
+#include <sys/ioctl.h>
+#include <linux/rtc.h>
+#include <lite/lite.h>
+
+#include "finit.h"
+#include "helpers.h"
+#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 */
+
+static int rtc_open(void)
+{
+	char *alt[] = {
+		"/dev/rtc",
+		"/dev/rtc0",
+		"/dev/misc/rtc"
+	};
+	size_t i;
+	int fd;
+
+	for (i = 0; i < NELEMS(alt); i++) {
+		fd = open(alt[i], O_RDONLY);
+		if (fd < 0)
+			continue;
+
+		return fd;
+	}
+
+	return -1;
+}
+
+static void rtc_save(void *arg)
+{
+	struct timeval tv = { 0 };
+	struct tm tm = { 0 };
+	int fd, rc = 0;
+
+	fd = rtc_open();
+	if (fd < 0)
+		return;
+
+	rc = gettimeofday(&tv, NULL);
+	if (rc < 0 || tv.tv_sec < RTC_TIMESTAMP_BEGIN_2000) {
+		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");
+		rc = 2;
+		goto out;
+	}
+
+	print_desc(NULL, "Saving system time (UTC) to RTC");
+	gmtime_r(&tv.tv_sec, &tm);
+	if (ioctl(fd, RTC_SET_TIME, &tm) < 0) {
+		if (EINVAL == errno)
+			goto invalid;
+		rc = 1;
+		goto out;
+	}
+
+out:
+	print(rc, NULL);
+	close(fd);
+}
+
+static void rtc_restore(void *arg)
+{
+	struct timeval tv = { 0 };
+	struct tm tm = { 0 };
+	int fd, rc = 0;
+
+	fd = rtc_open();
+	if (fd < 0)
+		return;
+
+	if (ioctl(fd, RTC_RD_TIME, &tm) < 0) {
+		char msg[120];
+
+		snprintf(msg, sizeof(msg), "Failed restoring system clock from RTC, %s",
+			 EINVAL == errno ? "RTC time is too old"   :
+			 ENOENT == errno ? "RTC has no saved time" : "see log for details");
+		print_desc(NULL, msg);
+
+	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)");
+		else if (ENOENT == errno)
+			logit(LOG_ERR, "RTC has no previously saved (valid) time.");
+		else
+			logit(LOG_ERR, "RTC error code %d: %m", errno);
+		rc = 2;
+		goto out;
+	}
+
+	print_desc(NULL, "Restoring system clock (UTC) from RTC");
+	tv.tv_sec = mktime(&tm);
+	if (tv.tv_sec < RTC_TIMESTAMP_BEGIN_2000) {
+		errno = EINVAL;
+		goto invalid;
+	}
+
+	if (settimeofday(&tv, NULL) == -1)
+		rc = 1;
+
+out:
+	print(rc, NULL);
+	close(fd);
+}
+
+static plugin_t plugin = {
+	.name = __FILE__,
+	.hook[HOOK_BASEFS_UP] = {
+		.cb  = rtc_restore
+	},
+	.hook[HOOK_SHUTDOWN] = {
+		.cb  = rtc_save
+	}
+};
+
+PLUGIN_INIT(plugin_init)
+{
+	plugin_register(&plugin);
+}
+
+PLUGIN_EXIT(plugin_exit)
+{
+	plugin_unregister(&plugin);
+}
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */