rtcwake: read accepted mode strings from /sys/power/state

The rtcwake has various mode names that are internal to the command,
listed in rtcwake_mode_string array, while some modes are dynamicaly
listed in /sys/power/state.  Together these form the allowed modes.

[kzak@redhat.com: - cleanup strv usage]

Reviewed-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 62 insertions, 55 deletions

diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
index d457a5bf6..ebfd420e2 100644
--- a/sys-utils/rtcwake.c
+++ b/sys-utils/rtcwake.c
@@ -39,6 +39,7 @@
 #include "optutils.h"
 #include "pathnames.h"
 #include "strutils.h"
+#include "strv.h"
 #include "timeutils.h"
 #include "xalloc.h"
 
@@ -53,28 +54,17 @@
 #define DEFAULT_DEVICE		"/dev/rtc0"
 
 enum rtc_modes {	/* manual page --mode option explains these. */
-	STANDBY_MODE = 0,
-	MEM_MODE,
-	FREEZE_MODE,
-	DISK_MODE,	/* end of Documentation/power/states.txt modes  */
-	OFF_MODE,
+	OFF_MODE = 0,
 	NO_MODE,
 	ON_MODE,
 	DISABLE_MODE,
-	SHOW_MODE
+	SHOW_MODE,
+
+	SYSFS_MODE	/* keep it last */
+
 };
 
-/* what system power mode to use?  for now handle only standardized mode
- * names; eventually when systems define their own state names, parse
- * /sys/power/state
- *
- * "on" is used just to test the RTC alarm mechanism, bypassing all the
- * wakeup-from-sleep infrastructure.  */
-static const char *mode_str[] = {
-	[STANDBY_MODE] = "standby",
-	[MEM_MODE] = "mem",
-	[FREEZE_MODE] = "freeze",
-	[DISK_MODE] = "disk",
+static const char *rtcwake_mode_string[] = {
 	[OFF_MODE] = "off",
 	[NO_MODE] = "no",
 	[ON_MODE] = "on",
@@ -89,6 +79,8 @@ enum clock_modes {
 };
 
 struct rtcwake_control {
+	char *mode_str;			/* name of the requested mode */
+	char **possible_modes;		/* modes listed in /sys/power/state */
 	char *adjfile;			/* adjtime file path */
 	enum clock_modes clock_mode;	/* hwclock timezone */
 	time_t sys_time;		/* system time */
@@ -245,23 +237,24 @@ static int setup_alarm(struct rtcwake_control *ctl, int fd, time_t *wakeup)
 	return 0;
 }
 
-static int is_suspend_available(const int suspend)
+static char **get_sys_power_states(struct rtcwake_control *ctl)
 {
-	int rc;
-	char buf[32];
-	FILE *f = fopen(SYS_POWER_STATE_PATH, "r");
-
-	if (!f)
-		return -1;
-	if (fgets(buf, sizeof buf, f) == NULL)
-		rc = -1;
-	else
-		rc = strstr(buf, mode_str[suspend]) != NULL;
-	fclose(f);
-	return rc;
+	if (!ctl->possible_modes) {
+		int fd;
+		char buf[256] = { 0 };
+
+		if (!(fd = open(SYS_POWER_STATE_PATH, O_RDONLY)))
+			return NULL;
+		if (read(fd, &buf, sizeof buf) < 0) {
+			close(fd);
+			return NULL;
+		}
+		ctl->possible_modes = strv_split(buf, " \n");
+	}
+	return ctl->possible_modes;
 }
 
-static void suspend_system(struct rtcwake_control *ctl, int suspend)
+static void suspend_system(struct rtcwake_control *ctl)
 {
 	FILE	*f = fopen(SYS_POWER_STATE_PATH, "w");
 
@@ -270,7 +263,7 @@ static void suspend_system(struct rtcwake_control *ctl, int suspend)
 		return;
 	}
 	if (!ctl->dryrun) {
-		fprintf(f, "%s\n", mode_str[suspend]);
+		fprintf(f, "%s\n", ctl->mode_str);
 		fflush(f);
 	}
 	/* this executes after wake from suspend */
@@ -338,13 +331,20 @@ static int print_alarm(struct rtcwake_control *ctl, int fd)
 	return 0;
 }
 
-static int get_mode(const char *optarg)
+static int get_rtc_mode(struct rtcwake_control *ctl, const char *optarg)
 {
-	size_t i = ARRAY_SIZE(mode_str);
+	size_t i;
+	char **modes = get_sys_power_states(ctl), **m;
 
-	while (i--)
-		if (!strcmp(optarg, mode_str[i]))
+	STRV_FOREACH(m, modes) {
+		if (strcmp(optarg, *m) == 0)
+			return SYSFS_MODE;
+	}
+
+	for (i = 0; i <= ARRAY_SIZE(rtcwake_mode_string); i++)
+		if (!strcmp(optarg, rtcwake_mode_string[i]))
 			return i;
+
 	return -EINVAL;
 }
 
@@ -364,25 +364,33 @@ static int open_dev_rtc(const char *devname)
 	return fd;
 }
 
-static void list_modes(void)
+static void list_modes(struct rtcwake_control *ctl)
 {
-	int i = ARRAY_SIZE(mode_str);
+	size_t i;
+	char **modes = get_sys_power_states(ctl), **m;
+
+	if (!modes)
+		errx(EXIT_FAILURE, _("could not read: %s"), SYS_POWER_STATE_PATH);
 
-	while (i--)
-		printf("%s%s", mode_str[i], i == 0 ? "" : " ");
+	STRV_FOREACH(m, modes)
+		printf("%s ", *m);
+
+	for (i = 0; i < ARRAY_SIZE(rtcwake_mode_string); i++)
+		printf("%s ", rtcwake_mode_string[i]);
 	putchar('\n');
 }
 
 int main(int argc, char **argv)
 {
 	struct rtcwake_control ctl = {
+		.mode_str = "suspend",		/* default mode */
 		.adjfile = _PATH_ADJTIME,
 		.clock_mode = CM_AUTO,
 		0
 	};
 	char *devname = DEFAULT_DEVICE;
 	unsigned seconds = 0;
-	int suspend = STANDBY_MODE;
+	int suspend = SYSFS_MODE;
 	int rc = EXIT_SUCCESS;
 	int t;
 	int fd;
@@ -418,6 +426,7 @@ int main(int argc, char **argv)
 	bindtextdomain(PACKAGE, LOCALEDIR);
 	textdomain(PACKAGE);
 	atexit(close_stdout);
+
 	while ((t = getopt_long(argc, argv, "A:ahd:lm:ns:t:uVv",
 					long_options, NULL)) != EOF) {
 		err_exclusive_options(t, long_options, excl, excl_st);
@@ -437,12 +446,13 @@ int main(int argc, char **argv)
 			break;
 
 		case OPT_LIST:
-			list_modes();
+			list_modes(&ctl);
 			return EXIT_SUCCESS;
 
 		case 'm':
-			if ((suspend = get_mode(optarg)) < 0)
+			if ((suspend = get_rtc_mode(&ctl, optarg)) < 0)
 				errx(EXIT_FAILURE, _("unrecognized suspend state '%s'"), optarg);
+			ctl.mode_str = optarg;
 			break;
 		case 'n':
 			ctl.dryrun = 1;
@@ -496,22 +506,18 @@ int main(int argc, char **argv)
 	fd = open_dev_rtc(devname);
 	if (suspend != ON_MODE && suspend != NO_MODE && !is_wakeup_enabled(devname))
 		errx(EXIT_FAILURE, _("%s not enabled for wakeup events"), devname);
+
 	/* relative or absolute alarm time, normalized to time_t */
 	if (get_basetimes(&ctl, fd) < 0)
 		exit(EXIT_FAILURE);
+
 	if (ctl.verbose)
 		printf(_("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n"),
 				alarm, ctl.sys_time, ctl.rtc_time, seconds);
+
 	if (suspend != DISABLE_MODE && suspend != SHOW_MODE) {
-		if ((suspend == STANDBY_MODE || suspend == MEM_MODE
-		     || suspend == FREEZE_MODE || suspend == DISK_MODE)
-		    && is_suspend_available(suspend) <= 0) {
-			errx(EXIT_FAILURE, _("suspend to \"%s\" unavailable"),
-			     mode_str[suspend]);
-		}
-		/* care about alarm setup only if the show|disable
-		 * modes are not set
-		 */
+		/* perform alarm setup when the show or disable modes are
+		 * not set */
 		if (alarm) {
 			if (alarm < ctl.sys_time)
 				errx(EXIT_FAILURE, _("time doesn't go backward to %s"),
@@ -527,11 +533,12 @@ int main(int argc, char **argv)
 				ctime(&alarm));
 		else
 			printf(_("%s: wakeup from \"%s\" using %s at %s"),
-				program_invocation_short_name, mode_str[suspend], devname,
+				program_invocation_short_name, ctl.mode_str, devname,
 				ctime(&alarm));
 		fflush(stdout);
 		xusleep(10 * 1000);
 	}
+
 	switch (suspend) {
 	case NO_MODE:
 		if (ctl.verbose)
@@ -591,9 +598,9 @@ int main(int argc, char **argv)
 		break;
 	default:
 		if (ctl.verbose)
-			printf(_("suspend mode: %s; suspending system\n"), mode_str[suspend]);
+			printf(_("suspend mode: %s; suspending system\n"), ctl.mode_str);
 		sync();
-		suspend_system(&ctl, suspend);
+		suspend_system(&ctl);
 	}
 
 	if (!ctl.dryrun) {