src/login/eloginctl.c

   1 /***
   2   This file is part of elogind.
   3
   4   Copyright 2017 Sven Eden
   5
   6   elogind is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   elogind is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with elogind; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20
  21 #include "bus-error.h"
  22 #include "bus-util.h"
  23 #include "eloginctl.h"
  24 #include "logind-action.h"
  25 #include "parse-util.h"
  26 #include "process-util.h"
  27 #include "sd-login.h"
  28 #include "spawn-polkit-agent.h"
  29 #include "string-util.h"
  30 #include "strv.h"
  31 #include "terminal-util.h"
  32 #include "user-util.h"
  33 #include "virt.h"
  34
  35
  36 elogind_action arg_action            = _ACTION_INVALID;
  37 bool           arg_ask_password      = true;
  38 bool           arg_ignore_inhibitors = false;
  39 bool           arg_no_wall           = false;
  40 BusTransport   arg_transport         = BUS_TRANSPORT_LOCAL;
  41 char**         arg_wall              = NULL;
  42 usec_t         arg_when              = 0;
  43
  44 static const struct {
  45         HandleAction action;
  46         const char*  verb;
  47 } action_table[_ACTION_MAX] = {
  48         [ACTION_POWEROFF]     = { HANDLE_POWEROFF,     "poweroff",    },
  49         [ACTION_REBOOT]       = { HANDLE_REBOOT,       "reboot",      },
  50         [ACTION_SUSPEND]      = { HANDLE_SUSPEND,      "suspend",     },
  51         [ACTION_HIBERNATE]    = { HANDLE_HIBERNATE,    "hibernate",   },
  52         [ACTION_HYBRID_SLEEP] = { HANDLE_HYBRID_SLEEP, "hybrid-sleep" },
  53 };
  54
  55 static int elogind_set_wall_message(sd_bus* bus, const char* msg);
  56
  57 static enum elogind_action verb_to_action(const char *verb) {
  58         enum elogind_action i;
  59
  60         for (i = _ACTION_INVALID; i < _ACTION_MAX; i++)
  61                 if (streq_ptr(action_table[i].verb, verb))
  62                         return i;
  63
  64         return _ACTION_INVALID;
  65 }
  66
  67 static int check_inhibitors(sd_bus* bus, enum elogind_action a) {
  68         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
  69         _cleanup_strv_free_ char **sessions = NULL;
  70         const char *what, *who, *why, *mode;
  71         uint32_t uid, pid;
  72         unsigned c = 0;
  73         char **s;
  74         int r;
  75
  76         if (arg_ignore_inhibitors)
  77                 return 0;
  78
  79         if (arg_when > 0)
  80                 return 0;
  81
  82         if (geteuid() == 0)
  83                 return 0;
  84
  85         if (!on_tty())
  86                 return 0;
  87
  88         r = sd_bus_call_method(
  89                         bus,
  90                         "org.freedesktop.login1",
  91                         "/org/freedesktop/login1",
  92                         "org.freedesktop.login1.Manager",
  93                         "ListInhibitors",
  94                         NULL,
  95                         &reply,
  96                         NULL);
  97         if (r < 0)
  98                 /* If logind is not around, then there are no inhibitors... */
  99                 return 0;
 100
 101         r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "(ssssuu)");
 102         if (r < 0)
 103                 return bus_log_parse_error(r);
 104
 105         while ((r = sd_bus_message_read(reply, "(ssssuu)", &what, &who, &why, &mode, &uid, &pid)) > 0) {
 106                 _cleanup_free_ char *comm = NULL, *user = NULL;
 107                 _cleanup_strv_free_ char **sv = NULL;
 108
 109                 if (!streq(mode, "block"))
 110                         continue;
 111
 112                 sv = strv_split(what, ":");
 113                 if (!sv)
 114                         return log_oom();
 115
 116                 if ((pid_t) pid < 0)
 117                         return log_error_errno(ERANGE, "Bad PID %"PRIu32": %m", pid);
 118
 119                 if (!strv_contains(sv,
 120                                    IN_SET(a,
 121                                           ACTION_HALT,
 122                                           ACTION_POWEROFF,
 123                                           ACTION_REBOOT,
 124                                           ACTION_KEXEC) ? "shutdown" : "sleep"))
 125                         continue;
 126
 127                 get_process_comm(pid, &comm);
 128                 user = uid_to_name(uid);
 129
 130                 log_warning("Operation inhibited by \"%s\" (PID "PID_FMT" \"%s\", user %s), reason is \"%s\".",
 131                             who, (pid_t) pid, strna(comm), strna(user), why);
 132
 133                 c++;
 134         }
 135         if (r < 0)
 136                 return bus_log_parse_error(r);
 137
 138         r = sd_bus_message_exit_container(reply);
 139         if (r < 0)
 140                 return bus_log_parse_error(r);
 141
 142         /* Check for current sessions */
 143         sd_get_sessions(&sessions);
 144         STRV_FOREACH(s, sessions) {
 145                 _cleanup_free_ char *type = NULL, *tty = NULL, *seat = NULL, *user = NULL, *service = NULL, *class = NULL;
 146
 147                 if (sd_session_get_uid(*s, &uid) < 0 || uid == getuid())
 148                         continue;
 149
 150                 if (sd_session_get_class(*s, &class) < 0 || !streq(class, "user"))
 151                         continue;
 152
 153                 if (sd_session_get_type(*s, &type) < 0 || (!streq(type, "x11") && !streq(type, "tty")))
 154                         continue;
 155
 156                 sd_session_get_tty(*s, &tty);
 157                 sd_session_get_seat(*s, &seat);
 158                 sd_session_get_service(*s, &service);
 159                 user = uid_to_name(uid);
 160
 161                 log_warning("User %s is logged in on %s.", strna(user), isempty(tty) ? (isempty(seat) ? strna(service) : seat) : tty);
 162                 c++;
 163         }
 164
 165         if (c <= 0)
 166                 return 0;
 167
 168         log_error("Please retry operation after closing inhibitors and logging out other users.\nAlternatively, ignore inhibitors and users with 'loginctl -i %s'.",
 169                   action_table[a].verb);
 170
 171         return -EPERM;
 172 }
 173
 174 int elogind_cancel_shutdown(sd_bus *bus) {
 175         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 176         int r;
 177
 178         r = sd_bus_call_method(
 179                         bus,
 180                         "org.freedesktop.login1",
 181                         "/org/freedesktop/login1",
 182                         "org.freedesktop.login1.Manager",
 183                         "CancelScheduledShutdown",
 184                         &error,
 185                         NULL, NULL);
 186         if (r < 0)
 187                 return log_warning_errno(r, "Failed to talk to elogind, shutdown hasn't been cancelled: %s", bus_error_message(&error, r));
 188
 189         return 0;
 190 }
 191
 192 void elogind_cleanup(void) {
 193         polkit_agent_close();
 194         strv_free(arg_wall);
 195 }
 196
 197 static int elogind_reboot(sd_bus *bus, enum elogind_action a) {
 198         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 199         const char *method  = NULL;
 200         int r;
 201         static const char *table[_ACTION_MAX] = {
 202                 [ACTION_REBOOT]          = "The system is going down for reboot NOW!",
 203                 [ACTION_POWEROFF]        = "The system is going down for power-off NOW!"
 204         };
 205
 206         if (!bus)
 207                 return -EIO;
 208
 209         polkit_agent_open_if_enabled();
 210
 211         switch (a) {
 212
 213         case ACTION_POWEROFF:
 214                 method = "PowerOff";
 215                 break;
 216
 217         case ACTION_REBOOT:
 218                 method = "Reboot";
 219                 break;
 220
 221         case ACTION_SUSPEND:
 222                 method = "Suspend";
 223                 break;
 224
 225         case ACTION_HIBERNATE:
 226                 method = "Hibernate";
 227                 break;
 228
 229         case ACTION_HYBRID_SLEEP:
 230                 method = "HybridSleep";
 231                 break;
 232
 233         default:
 234                 return -EINVAL;
 235         }
 236
 237         r = elogind_set_wall_message(bus, table[a]);
 238
 239         if (r < 0) {
 240                 log_warning_errno(r, "Failed to set wall message, ignoring: %s",
 241                                   bus_error_message(&error, r));
 242                 sd_bus_error_free(&error);
 243         }
 244
 245         /* Now call elogind itself to request the operation */
 246         r = sd_bus_call_method(
 247                         bus,
 248                         "org.freedesktop.login1",
 249                         "/org/freedesktop/login1",
 250                         "org.freedesktop.login1.Manager",
 251                         method,
 252                         &error,
 253                         NULL,
 254                         "b",
 255                         arg_ask_password);
 256
 257         if (r < 0)
 258                 log_error("Failed to execute operation: %s", bus_error_message(&error, r));
 259
 260         return r;
 261 }
 262
 263 static int elogind_schedule_shutdown(sd_bus *bus, enum elogind_action a) {
 264         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 265         const char *method  = NULL;
 266         int r;
 267
 268         if (!bus)
 269                 return -EIO;
 270
 271         polkit_agent_open_if_enabled();
 272
 273         switch (a) {
 274
 275         case ACTION_POWEROFF:
 276                 method = "poweroff";
 277                 break;
 278
 279         case ACTION_REBOOT:
 280                 method = "reboot";
 281                 break;
 282
 283         default:
 284                 return -EINVAL;
 285         }
 286
 287         r = elogind_set_wall_message(bus, NULL);
 288
 289         if (r < 0) {
 290                 log_warning_errno(r, "Failed to set wall message, ignoring: %s",
 291                                   bus_error_message(&error, r));
 292                 sd_bus_error_free(&error);
 293         }
 294
 295         r = sd_bus_call_method(
 296                         bus,
 297                         "org.freedesktop.login1",
 298                         "/org/freedesktop/login1",
 299                         "org.freedesktop.login1.Manager",
 300                         "ScheduleShutdown",
 301                         &error,
 302                         NULL,
 303                         "st",
 304                         method,
 305                         arg_when);
 306
 307         if (r < 0)
 308                 log_error("Failed to execute operation: %s", bus_error_message(&error, r));
 309
 310         return r;
 311 }
 312
 313 static int elogind_set_wall_message(sd_bus* bus, const char* msg) {
 314         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 315         _cleanup_free_ char *m = NULL;
 316         int r;
 317
 318         if (strv_extend(&arg_wall, msg) < 0)
 319                 return log_oom();
 320
 321         m = strv_join(arg_wall, " ");
 322         if (!m)
 323                 return log_oom();
 324
 325         r = sd_bus_call_method(
 326                         bus,
 327                         "org.freedesktop.login1",
 328                         "/org/freedesktop/login1",
 329                         "org.freedesktop.login1.Manager",
 330                         "SetWallMessage",
 331                         &error,
 332                         NULL,
 333                         "sb",
 334                         m,
 335                         !arg_no_wall);
 336
 337         if (r < 0)
 338                 return log_warning_errno(r, "Failed to set wall message, ignoring: %s", bus_error_message(&error, r));
 339
 340         return 0;
 341 }
 342
 343 static int parse_shutdown_time_spec(const char *t, usec_t *_u) {
 344         assert(t);
 345         assert(_u);
 346
 347         if (streq(t, "now"))
 348                 *_u = 0;
 349         else if (!strchr(t, ':')) {
 350                 uint64_t u;
 351
 352                 if (safe_atou64(t, &u) < 0)
 353                         return -EINVAL;
 354
 355                 *_u = now(CLOCK_REALTIME) + USEC_PER_MINUTE * u;
 356         } else {
 357                 char *e = NULL;
 358                 long hour, minute;
 359                 struct tm tm = {};
 360                 time_t s;
 361                 usec_t n;
 362
 363                 errno = 0;
 364                 hour = strtol(t, &e, 10);
 365                 if (errno > 0 || *e != ':' || hour < 0 || hour > 23)
 366                         return -EINVAL;
 367
 368                 minute = strtol(e+1, &e, 10);
 369                 if (errno > 0 || *e != 0 || minute < 0 || minute > 59)
 370                         return -EINVAL;
 371
 372                 n = now(CLOCK_REALTIME);
 373                 s = (time_t) (n / USEC_PER_SEC);
 374
 375                 assert_se(localtime_r(&s, &tm));
 376
 377                 tm.tm_hour = (int) hour;
 378                 tm.tm_min = (int) minute;
 379                 tm.tm_sec = 0;
 380
 381                 assert_se(s = mktime(&tm));
 382
 383                 *_u = (usec_t) s * USEC_PER_SEC;
 384
 385                 while (*_u <= n)
 386                         *_u += USEC_PER_DAY;
 387         }
 388
 389         return 0;
 390 }
 391
 392 void polkit_agent_open_if_enabled(void) {
 393
 394         /* Open the polkit agent as a child process if necessary */
 395
 396         if (!arg_ask_password)
 397                 return;
 398
 399         if (arg_transport != BUS_TRANSPORT_LOCAL)
 400                 return;
 401
 402         polkit_agent_open();
 403 }
 404
 405 int start_special(int argc, char *argv[], void *userdata) {
 406         sd_bus *bus = userdata;
 407         enum elogind_action a;
 408         int r;
 409         char** wall = NULL;
 410
 411         assert(argv);
 412
 413         a = verb_to_action(argv[0]);
 414
 415         /* Switch to cancel shutdown, if a shutdown action was requested,
 416            and the option to cancel it was set: */
 417         if ( IN_SET(a, ACTION_POWEROFF, ACTION_REBOOT)
 418           && (arg_action == ACTION_CANCEL_SHUTDOWN) )
 419                 return elogind_cancel_shutdown(bus);
 420
 421         r = check_inhibitors(bus, a);
 422         if (r < 0)
 423                 return r;
 424
 425         /* No power off actions in chroot environments */
 426         if ((a == ACTION_POWEROFF ||
 427              a == ACTION_REBOOT) &&
 428             (running_in_chroot() > 0) ) {
 429                 log_info("Running in chroot, ignoring request.");
 430                 return 0;
 431         }
 432
 433         /* Check time arguments */
 434         if ( IN_SET(a, ACTION_POWEROFF, ACTION_REBOOT)
 435           && (argc > 1)
 436           && (arg_action != ACTION_CANCEL_SHUTDOWN) ) {
 437                 r = parse_shutdown_time_spec(argv[1], &arg_when);
 438                 if (r < 0) {
 439                         log_error("Failed to parse time specification: %s", argv[optind]);
 440                         return r;
 441                 }
 442         } else
 443                 arg_when = now(CLOCK_REALTIME) + USEC_PER_MINUTE;
 444
 445         /* The optional user wall message must be set */
 446         if ((argc > 1) && (arg_action == ACTION_CANCEL_SHUTDOWN) )
 447                 /* No time argument for shutdown cancel */
 448                 wall = argv + 1;
 449         else if (argc > 2)
 450                 /* We skip the time argument */
 451                 wall = argv + 2;
 452
 453         if (wall) {
 454                 arg_wall = strv_copy(wall);
 455                 if (!arg_wall)
 456                         return log_oom();
 457         }
 458
 459         /* Perform requested action */
 460         if (IN_SET(a,
 461                    ACTION_POWEROFF,
 462                    ACTION_REBOOT,
 463                    ACTION_SUSPEND,
 464                    ACTION_HIBERNATE,
 465                    ACTION_HYBRID_SLEEP)) {
 466                 if (arg_when > 0)
 467                         return elogind_schedule_shutdown(bus, a);
 468                 else
 469                         return elogind_reboot(bus, a);
 470         }
 471
 472         return -EOPNOTSUPP;
 473 }
 474