utils: add lxc_make_tmpfile()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/utils.c

@@ -2397,3 +2397,23 @@ bool lxc_nic_exists(char *nic)
 
 	return true;
 }
+
+int lxc_make_tmpfile(char *template, bool rm)
+{
+	int fd, ret;
+
+	fd = mkstemp(template);
+	if (fd < 0)
+		return -1;
+
+	if (!rm)
+		return fd;
+
+	ret = unlink(template);
+	if (ret < 0) {
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}

src/lxc/utils.h

@@ -456,5 +456,6 @@ typedef __typeof__(((struct statfs *)NULL)->f_type) fs_type_magic;
 extern bool has_fs_type(const char *path, fs_type_magic magic_val);
 extern bool is_fs_type(const struct statfs *fs, fs_type_magic magic_val);
 extern bool lxc_nic_exists(char *nic);
+extern int lxc_make_tmpfile(char *template, bool rm);
 
 #endif /* __LXC_UTILS_H */