src/login/logind-utmp.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <unistd.h>
   5
   6 #include "sd-messages.h"
   7
   8 #include "alloc-util.h"
   9 #include "audit-util.h"
  10 #include "bus-common-errors.h"
  11 #include "bus-error.h"
  12 #include "bus-util.h"
  13 #include "event-util.h"
  14 #include "format-util.h"
  15 #include "logind.h"
  16 #include "path-util.h"
  17 #include "special.h"
  18 #include "strv.h"
  19 #include "unit-name.h"
  20 #include "user-util.h"
  21 #include "utmp-wtmp.h"
  22
  23 _const_ static usec_t when_wall(usec_t n, usec_t elapse) {
  24         static const int wall_timers[] = {
  25                 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
  26                 25, 40, 55, 70, 100, 130, 150, 180,
  27         };
  28
  29         /* If the time is already passed, then don't announce */
  30         if (n >= elapse)
  31                 return 0;
  32
  33         usec_t left = elapse - n;
  34
  35         for (unsigned i = 1; i < ELEMENTSOF(wall_timers); i++)
  36                 if (wall_timers[i] * USEC_PER_MINUTE >= left)
  37                         return left - wall_timers[i-1] * USEC_PER_MINUTE;
  38
  39         return left % USEC_PER_HOUR;
  40 }
  41
  42 bool logind_wall_tty_filter(const char *tty, bool is_local, void *userdata) {
  43         Manager *m = ASSERT_PTR(userdata);
  44
  45         assert(m->scheduled_shutdown_action);
  46
  47         const char *p = path_startswith(tty, "/dev/");
  48         if (!p)
  49                 return true;
  50
  51         /* Do not send information about events which do not destroy local sessions to local terminals. We
  52          * can assume that if the system enters sleep or hibernation, this will be visible in an obvious way
  53          * for any local user. And once the systems exits sleep or hibernation, the notification would be
  54          * just noise, in particular for auto-suspend. */
  55         if (is_local &&
  56             IN_SET(m->scheduled_shutdown_action->handle,
  57                    HANDLE_SUSPEND,
  58                    HANDLE_HIBERNATE,
  59                    HANDLE_HYBRID_SLEEP,
  60                    HANDLE_SUSPEND_THEN_HIBERNATE))
  61                 return false;
  62
  63         return !streq_ptr(p, m->scheduled_shutdown_tty);
  64 }
  65
  66 static int warn_wall(Manager *m, usec_t n) {
  67         assert(m);
  68
  69         if (!m->scheduled_shutdown_action)
  70                 return 0;
  71
  72         bool left = m->scheduled_shutdown_timeout > n;
  73
  74         _cleanup_free_ char *l = NULL;
  75         if (asprintf(&l, "%s%sThe system will %s %s%s!",
  76                      strempty(m->wall_message),
  77                      isempty(m->wall_message) ? "" : "\n",
  78                      handle_action_verb_to_string(m->scheduled_shutdown_action->handle),
  79                      left ? "at " : "now",
  80                      left ? FORMAT_TIMESTAMP(m->scheduled_shutdown_timeout) : "") < 0) {
  81
  82                 log_oom();
  83                 return 1;  /* We're out-of-memory for now, but let's try to print the message later */
  84         }
  85
  86         _cleanup_free_ char *username = uid_to_name(m->scheduled_shutdown_uid);
  87
  88         int level = left ? LOG_INFO : LOG_NOTICE;
  89
  90         log_struct(level,
  91                    LOG_MESSAGE("%s", l),
  92                    "ACTION=%s", handle_action_to_string(m->scheduled_shutdown_action->handle),
  93                    "MESSAGE_ID=" SD_MESSAGE_SHUTDOWN_SCHEDULED_STR,
  94                    username ? "OPERATOR=%s" : NULL, username);
  95
  96         if (m->enable_wall_messages)
  97                 utmp_wall(l, username, m->scheduled_shutdown_tty, logind_wall_tty_filter, m);
  98
  99         return 1;
 100 }
 101
 102 static int wall_message_timeout_handler(
 103                         sd_event_source *s,
 104                         uint64_t usec,
 105                         void *userdata) {
 106
 107         Manager *m = ASSERT_PTR(userdata);
 108         int r;
 109
 110         assert(s == m->wall_message_timeout_source);
 111
 112         usec_t n = now(CLOCK_REALTIME);
 113
 114         r = warn_wall(m, n);
 115         if (r == 0)
 116                 return 0;
 117
 118         usec_t next = when_wall(n, m->scheduled_shutdown_timeout);
 119         if (next > 0) {
 120                 r = sd_event_source_set_time(s, n + next);
 121                 if (r < 0)
 122                         return log_error_errno(r, "sd_event_source_set_time() failed. %m");
 123
 124                 r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT);
 125                 if (r < 0)
 126                         return log_error_errno(r, "sd_event_source_set_enabled() failed. %m");
 127         }
 128
 129         return 0;
 130 }
 131
 132 int manager_setup_wall_message_timer(Manager *m) {
 133         int r;
 134
 135         assert(m);
 136
 137         usec_t n = now(CLOCK_REALTIME);
 138         usec_t elapse = m->scheduled_shutdown_timeout;
 139
 140         /* wall message handling */
 141
 142         if (!m->scheduled_shutdown_action)
 143                 return 0;
 144
 145         if (elapse > 0 && elapse < n)
 146                 return 0;
 147
 148         /* Warn immediately if less than 15 minutes are left */
 149         if (elapse == 0 || elapse - n < 15 * USEC_PER_MINUTE) {
 150                 r = warn_wall(m, n);
 151                 if (r == 0)
 152                         return 0;
 153         }
 154
 155         elapse = when_wall(n, elapse);
 156         if (elapse == 0)
 157                 return 0;
 158
 159         r = event_reset_time(m->event, &m->wall_message_timeout_source,
 160                              CLOCK_REALTIME,
 161                              n + elapse, 0,
 162                              wall_message_timeout_handler, m,
 163                              0, "wall-message-timer", true);
 164
 165         if (r < 0) {
 166                 m->wall_message_timeout_source = sd_event_source_unref(m->wall_message_timeout_source);
 167                 return log_error_errno(r, "Failed to set up wall message timer: %m");
 168         }
 169
 170         return 0;
 171 }