1 files changed, 171 insertions, 0 deletions
diff --git a/src/login/logind-utmp.c b/src/login/logind-utmp.c
new file mode 100644
index 0000000..3f1503a
--- /dev/null
+++ b/src/login/logind-utmp.c
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "audit-util.h"
+#include "bus-common-errors.h"
+#include "bus-error.h"
+#include "bus-util.h"
+#include "event-util.h"
+#include "format-util.h"
+#include "logind.h"
+#include "path-util.h"
+#include "special.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "user-util.h"
+#include "utmp-wtmp.h"
+
+_const_ static usec_t when_wall(usec_t n, usec_t elapse) {
+        static const int wall_timers[] = {
+                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+                25, 40, 55, 70, 100, 130, 150, 180,
+        };
+
+        /* If the time is already passed, then don't announce */
+        if (n >= elapse)
+                return 0;
+
+        usec_t left = elapse - n;
+
+        for (unsigned i = 1; i < ELEMENTSOF(wall_timers); i++)
+                if (wall_timers[i] * USEC_PER_MINUTE >= left)
+                        return left - wall_timers[i-1] * USEC_PER_MINUTE;
+
+        return left % USEC_PER_HOUR;
+}
+
+bool logind_wall_tty_filter(const char *tty, bool is_local, void *userdata) {
+        Manager *m = ASSERT_PTR(userdata);
+
+        assert(m->scheduled_shutdown_action);
+
+        const char *p = path_startswith(tty, "/dev/");
+        if (!p)
+                return true;
+
+        /* Do not send information about events which do not destroy local sessions to local terminals. We
+         * can assume that if the system enters sleep or hibernation, this will be visible in an obvious way
+         * for any local user. And once the systems exits sleep or hibernation, the notification would be
+         * just noise, in particular for auto-suspend. */
+        if (is_local &&
+            IN_SET(m->scheduled_shutdown_action->handle,
+                   HANDLE_SUSPEND,
+                   HANDLE_HIBERNATE,
+                   HANDLE_HYBRID_SLEEP,
+                   HANDLE_SUSPEND_THEN_HIBERNATE))
+                return false;
+
+        return !streq_ptr(p, m->scheduled_shutdown_tty);
+}
+
+static int warn_wall(Manager *m, usec_t n) {
+        assert(m);
+
+        if (!m->scheduled_shutdown_action)
+                return 0;
+
+        bool left = m->scheduled_shutdown_timeout > n;
+
+        _cleanup_free_ char *l = NULL;
+        if (asprintf(&l, "%s%sThe system will %s %s%s!",
+                     strempty(m->wall_message),
+                     isempty(m->wall_message) ? "" : "\n",
+                     handle_action_verb_to_string(m->scheduled_shutdown_action->handle),
+                     left ? "at " : "now",
+                     left ? FORMAT_TIMESTAMP(m->scheduled_shutdown_timeout) : "") < 0) {
+
+                log_oom();
+                return 1;  /* We're out-of-memory for now, but let's try to print the message later */
+        }
+
+        _cleanup_free_ char *username = uid_to_name(m->scheduled_shutdown_uid);
+
+        int level = left ? LOG_INFO : LOG_NOTICE;
+
+        log_struct(level,
+                   LOG_MESSAGE("%s", l),
+                   "ACTION=%s", handle_action_to_string(m->scheduled_shutdown_action->handle),
+                   "MESSAGE_ID=" SD_MESSAGE_SHUTDOWN_SCHEDULED_STR,
+                   username ? "OPERATOR=%s" : NULL, username);
+
+        if (m->enable_wall_messages)
+                utmp_wall(l, username, m->scheduled_shutdown_tty, logind_wall_tty_filter, m);
+
+        return 1;
+}
+
+static int wall_message_timeout_handler(
+                        sd_event_source *s,
+                        uint64_t usec,
+                        void *userdata) {
+
+        Manager *m = ASSERT_PTR(userdata);
+        int r;
+
+        assert(s == m->wall_message_timeout_source);
+
+        usec_t n = now(CLOCK_REALTIME);
+
+        r = warn_wall(m, n);
+        if (r == 0)
+                return 0;
+
+        usec_t next = when_wall(n, m->scheduled_shutdown_timeout);
+        if (next > 0) {
+                r = sd_event_source_set_time(s, n + next);
+                if (r < 0)
+                        return log_error_errno(r, "sd_event_source_set_time() failed. %m");
+
+                r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
+                if (r < 0)
+                        return log_error_errno(r, "sd_event_source_set_enabled() failed. %m");
+        }
+
+        return 0;
+}
+
+int manager_setup_wall_message_timer(Manager *m) {
+        int r;
+
+        assert(m);
+
+        usec_t n = now(CLOCK_REALTIME);
+        usec_t elapse = m->scheduled_shutdown_timeout;
+
+        /* wall message handling */
+
+        if (!m->scheduled_shutdown_action)
+                return 0;
+
+        if (elapse > 0 && elapse < n)
+                return 0;
+
+        /* Warn immediately if less than 15 minutes are left */
+        if (elapse == 0 || elapse - n < 15 * USEC_PER_MINUTE) {
+                r = warn_wall(m, n);
+                if (r == 0)
+                        return 0;
+        }
+
+        elapse = when_wall(n, elapse);
+        if (elapse == 0)
+                return 0;
+
+        r = event_reset_time(m->event, &m->wall_message_timeout_source,
+                             CLOCK_REALTIME,
+                             n + elapse, 0,
+                             wall_message_timeout_handler, m,
+                             0, "wall-message-timer", true);
+
+        if (r < 0) {
+                m->wall_message_timeout_source = sd_event_source_unref(m->wall_message_timeout_source);
+                return log_error_errno(r, "Failed to set up wall message timer: %m");
+        }
+
+        return 0;
+}