Started writing the management program.

src/backing.c

@@ -0,0 +1,66 @@
+#include "backing.h"
+
+#include "utils.h"
+#include "sandbox.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+char* get_backings_path(void) {
+	return format("%s/%s", MASTER_DIRECTORY, BACKINGS_DIRECTORY);
+}
+
+bool is_valid_backing_name(const char* name) {
+	if (name == NULL)
+		return false;
+
+	// Check that the name is not empty
+	size_t length = strlen(name);
+	if (length == 0)
+		return false;
+
+	// Check that the name is a number (the number is the timestamp of the backing disk creation)
+	for (size_t i = 0; i < length; i++)
+		if (name[i] < '0' || name[i] > '9')
+			return false;
+
+	return true;
+}
+
+char* get_backing_path(const char* backing) {
+	char* backings_path = get_backings_path();
+	if (backings_path == NULL)
+		return NULL;
+
+	// Combine the backings path with the backing name
+	char* backing_path = format("%s/%s", backings_path, backing);
+
+	// Free the backings path
+	free(backings_path);
+
+	return backing_path;
+}
+
+bool backing_exists(const char* backing) {
+	char* backing_path = get_backing_path(backing);
+	if (backing_path == NULL)
+		return false;
+
+	// Check if the backing path exists
+	struct stat statbuf;
+	int result = stat(backing_path, &statbuf);
+
+	// Free the backing path
+	free(backing_path);
+
+	if (result != 0)
+		return false;
+
+	if (!S_ISREG(statbuf.st_mode))
+		return false;
+
+	return true;
+}