2 files changed, 67 insertions, 0 deletions
diff --git a/src/update-done/meson.build b/src/update-done/meson.build
new file mode 100644
index 0000000..89a79b6
--- /dev/null
+++ b/src/update-done/meson.build
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+executables += [
+        libexec_template + {
+                'name' : 'systemd-update-done',
+                'sources' : files('update-done.c'),
+        },
+]
diff --git a/src/update-done/update-done.c b/src/update-done/update-done.c
new file mode 100644
index 0000000..f448b3b
--- /dev/null
+++ b/src/update-done/update-done.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fileio-label.h"
+#include "selinux-util.h"
+#include "time-util.h"
+
+#define MESSAGE                                                         \
+        "# This file was created by systemd-update-done. Its only \n"   \
+        "# purpose is to hold a timestamp of the time this directory\n" \
+        "# was updated. See man:systemd-update-done.service(8).\n"
+
+static int apply_timestamp(const char *path, struct timespec *ts) {
+        _cleanup_free_ char *message = NULL;
+        int r;
+
+        /*
+         * We store the timestamp both as mtime of the file and in the file itself,
+         * to support filesystems which cannot store nanosecond-precision timestamps.
+         */
+
+        if (asprintf(&message,
+                     MESSAGE
+                     "TIMESTAMP_NSEC=" NSEC_FMT "\n",
+                     timespec_load_nsec(ts)) < 0)
+                return log_oom();
+
+        r = write_string_file_atomic_label_ts(path, message, ts);
+        if (r == -EROFS)
+                log_debug_errno(r, "Cannot create \"%s\", file system is read-only.", path);
+        else if (r < 0)
+                return log_error_errno(r, "Failed to write \"%s\": %m", path);
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
+        struct stat st;
+        int r, q = 0;
+
+        log_setup();
+
+        if (stat("/usr", &st) < 0) {
+                log_error_errno(errno, "Failed to stat /usr: %m");
+                return EXIT_FAILURE;
+        }
+
+        r = mac_init();
+        if (r < 0)
+                return EXIT_FAILURE;
+
+        r = apply_timestamp("/etc/.updated", &st.st_mtim);
+        q = apply_timestamp("/var/.updated", &st.st_mtim);
+
+        return r < 0 || q < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}