1 files changed, 83 insertions, 0 deletions
diff --git a/src/shared/reboot-util.c b/src/shared/reboot-util.c
new file mode 100644
index 0000000000..ca40159b96
--- /dev/null
+++ b/src/shared/reboot-util.c
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "raw-reboot.h"
+#include "reboot-util.h"
+#include "string-util.h"
+#include "umask-util.h"
+#include "virt.h"
+
+int update_reboot_parameter_and_warn(const char *parameter) {
+        int r;
+
+        if (isempty(parameter)) {
+                if (unlink("/run/systemd/reboot-param") < 0) {
+                        if (errno == ENOENT)
+                                return 0;
+
+                        return log_warning_errno(errno, "Failed to unlink reboot parameter file: %m");
+                }
+
+                return 0;
+        }
+
+        RUN_WITH_UMASK(0022) {
+                r = write_string_file("/run/systemd/reboot-param", parameter,
+                                      WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
+                if (r < 0)
+                        return log_warning_errno(r, "Failed to write reboot parameter file: %m");
+        }
+
+        return 0;
+}
+
+int reboot_with_parameter(RebootFlags flags) {
+        int r;
+
+        /* Reboots the system with a parameter that is read from /run/systemd/reboot-param. Returns 0 if REBOOT_DRY_RUN
+         * was set and the actual reboot operation was hence skipped. If REBOOT_FALLBACK is set and the reboot with
+         * parameter doesn't work out a fallback to classic reboot() is attempted. If REBOOT_FALLBACK is not set, 0 is
+         * returned instead, which should be considered indication for the caller to fall back to reboot() on its own,
+         * or somehow else deal with this. If REBOOT_LOG is specified will log about what it is going to do, as well as
+         * all errors. */
+
+        if (detect_container() == 0) {
+                _cleanup_free_ char *parameter = NULL;
+
+                r = read_one_line_file("/run/systemd/reboot-param", &parameter);
+                if (r < 0 && r != -ENOENT)
+                        log_full_errno(flags & REBOOT_LOG ? LOG_WARNING : LOG_DEBUG, r,
+                                       "Failed to read reboot parameter file, ignoring: %m");
+
+                if (!isempty(parameter)) {
+
+                        log_full(flags & REBOOT_LOG ? LOG_INFO : LOG_DEBUG,
+                                 "Rebooting with argument '%s'.", parameter);
+
+                        if (flags & REBOOT_DRY_RUN)
+                                return 0;
+
+                        (void) raw_reboot(LINUX_REBOOT_CMD_RESTART2, parameter);
+
+                        log_full_errno(flags & REBOOT_LOG ? LOG_WARNING : LOG_DEBUG, errno,
+                                       "Failed to reboot with parameter, retrying without: %m");
+                }
+        }
+
+        if (!(flags & REBOOT_FALLBACK))
+                return 0;
+
+        log_full(flags & REBOOT_LOG ? LOG_INFO : LOG_DEBUG, "Rebooting.");
+
+        if (flags & REBOOT_DRY_RUN)
+                return 0;
+
+        (void) reboot(RB_AUTOBOOT);
+
+        return log_full_errno(flags & REBOOT_LOG ? LOG_ERR : LOG_DEBUG, errno, "Failed to reboot: %m");
+}