cleanup and fix savefile creation

sbl.c

@@ -20,7 +20,7 @@
 
 const char *savefile_paths[] = {
 	NULL, /* reserved for external savefile path */
-	"/etc/sbl/savefile"
+	"/etc/sblsave"
 };
 
 enum action {
@@ -28,7 +28,10 @@ enum action {
 };
 
 static uid_t ruid;
-int device_index = 0;
+static int device_index = 0;
+static const char *savefile;
+static int max_brightness;
+static const char *device_path;
 
 static void die (const char *, ...);
 static void usage (void);
@@ -40,7 +43,7 @@ static int save_value (float);
 static int get_max_brightness (void);
 static float get_saved_value (void);
 static float get_current_brightness (void);
-static const char * backlight_path (int);
+static const char * get_device_path (int);
 static const char * get_savefile (void);
 
 int main (int argc, char *argv[])
@@ -93,7 +96,11 @@ int main (int argc, char *argv[])
 	}
 
 	ruid = getuid ();
-
+	if (!(device_path = get_device_path(device_index)))
+		die("invalid device index");
+	max_brightness = get_max_brightness();
+	savefile = get_savefile();
+	
 	switch (act) {
 		case DISPLAY:
 			printf("%.2f\n", get_current_brightness());
@@ -127,11 +134,13 @@ int main (int argc, char *argv[])
 int save_value (float value)
 {
 	FILE *fd;
-	fd = fopen(get_savefile(), "w");
+	change_permissions(savefile);
+	fd = fopen(savefile, "w");
 	if (!fd)
 		die("could not open savefile");
 	fprintf(fd, "%f\n", value);
 	fclose(fd);
+	restore_permissions();
 	return 1;
 }
 
@@ -139,7 +148,7 @@ float get_saved_value (void)
 {
 	FILE *fd;
 	float rtf = -1;
-	fd = fopen(get_savefile(), "r");
+	fd = fopen(savefile, "r");
 	if (!fd)
 		die("could not open savefile");
 	fscanf(fd, "%f", &rtf);
@@ -152,10 +161,7 @@ float get_current_brightness (void)
 	FILE *fd;
 	char buf[PATH_MAX] = {0};
 	int cb = -1;
-	const char *path = backlight_path(device_index);
-	if (!path)
-		die("invalid device index"); 
-	strcpy(buf, path);
+	strcpy(buf, device_path);
 	strcat(buf, "/brightness");
 	fd = fopen(buf, "r");
 	if (!fd)
@@ -163,7 +169,7 @@ float get_current_brightness (void)
 	fscanf(fd, "%d", &cb);
 	fclose(fd);
  
-	return ((float)cb / (float)get_max_brightness()) * 100.0;;
+	return ((float)cb / (float)max_brightness) * 100.0;;
 }
 
 int get_max_brightness (void)
@@ -171,10 +177,7 @@ int get_max_brightness (void)
 	FILE *fd;
 	char buf[PATH_MAX] = {0};
 	int rti = -1;
-	const char *path = backlight_path(device_index);
-	if (!path)
-		die("invalid device index"); 
-	strcpy(buf, path);
+	strcpy(buf, device_path);
 	strcat(buf, "/max_brightness");
 	fd = fopen(buf, "r");
 	if (!fd)
@@ -226,10 +229,12 @@ const char * get_savefile (void)
 			}
 
 			strcpy(buf, result.we_wordv[0]);
-		if ((fd = fopen(result.we_wordv[0], "w")))
-			break;
+			change_permissions(buf);
+			if ((fd = fopen(result.we_wordv[0], "w")))
+				break;
 		}
 	}
+	restore_permissions();
 	wordfree(&result);
 	if (!fd)
 		die("could not open or create a savefile");
@@ -237,7 +242,7 @@ const char * get_savefile (void)
 	return buf;
 }	
 
-const char * backlight_path (int index)
+const char * get_device_path (int index)
 {
 	DIR *dp;
 	struct dirent *de;
@@ -276,7 +281,7 @@ void list_cards (void)
 {
 	int i = 0;
 	const char *s;
-	for (; (s = backlight_path(i)); i++)
+	for (; (s = get_device_path(i)); i++)
 		printf("%d: %s\n", i, s);
 	exit(EXIT_SUCCESS);
 }
@@ -285,18 +290,15 @@ void set_brightness (float value)
 {
 	int set;
 	char buf[PATH_MAX] = {0};
-	const char *path = backlight_path(device_index);
 	FILE *fd;
 	if (value > 100)
 		value = 100;
 	if (value < BL_MIN)
 		value = BL_MIN;
-	set = (value/100.0) * get_max_brightness();
+	set = (value/100.0) * max_brightness;
 	if (set < 0)
-		return;
-	if (!path)
-		die("invalid device index"); 
-	strcpy(buf, path);
+		return; 
+	strcpy(buf, device_path);
 	strcat(buf, "/brightness");
 	change_permissions(buf);
 	fd = fopen(buf, "w");
@@ -312,8 +314,23 @@ void change_permissions (const char *path)
 {
 	int status;
 	struct stat st;
-
-	stat(path, &st);
+	static char buf[PATH_MAX];
+	char *p;
+
+	if (stat(path, &st) == -1) {
+		if (errno != ENOENT)
+			die("stat error");
+		strcpy(buf, path);
+		for (p = &buf[strlen(buf) - 1]; *p && p != buf; p--) {
+			if (*p == '/') {
+				*p = '\0';
+				if (stat(buf, &st) != -1)
+					break;
+			}
+		}
+		if (p == buf)
+			die("stat error, invalid path");
+	}
 	status = seteuid(st.st_uid);
 	if (status < 0)
 		die("could not setuid");