src/seat.c

   1 /*
   2  * Copyright (C) 2010-2011 Robert Ancell.
   3  * Author: Robert Ancell <robert.ancell@canonical.com>
   4  *
   5  * This program is free software: you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option) any later
   8  * version. See http://www.gnu.org/copyleft/gpl.html the full text of the
   9  * license.
  10  */
  11
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/wait.h>
  15
  16 #include "seat.h"
  17 #include "configuration.h"
  18 #include "guest-account.h"
  19 #include "greeter-session.h"
  20 #include "session-config.h"
  21
  22 enum {
  23     SESSION_ADDED,
  24     RUNNING_USER_SESSION,
  25     SESSION_REMOVED,
  26     STOPPED,
  27     LAST_SIGNAL
  28 };
  29 static guint signals[LAST_SIGNAL] = { 0 };
  30
  31 struct SeatPrivate
  32 {
  33     /* XDG name for this seat */
  34     gchar *name;
  35
  36     /* Configuration for this seat */
  37     GHashTable *properties;
  38
  39     /* TRUE if this seat can run multiple sessions at once */
  40     gboolean supports_multi_session;
  41
  42     /* TRUE if display server can be shared for sessions */
  43     gboolean share_display_server;
  44
  45     /* The display servers on this seat */
  46     GList *display_servers;
  47
  48     /* The sessions on this seat */
  49     GList *sessions;
  50
  51     /* The last session set to active */
  52     Session *active_session;
  53
  54     /* The session belonging to the active greeter user */
  55     Session *next_session;
  56
  57     /* The session to set active when it starts */
  58     Session *session_to_activate;
  59
  60     /* TRUE once we have started */
  61     gboolean started;
  62
  63     /* TRUE if stopping this seat (waiting for displays to stop) */
  64     gboolean stopping;
  65
  66     /* TRUE if stopped */
  67     gboolean stopped;
  68
  69     /* The greeter to be started to replace the current one */
  70     GreeterSession *replacement_greeter;
  71 };
  72
  73 static void seat_logger_iface_init (LoggerInterface *iface);
  74
  75 G_DEFINE_TYPE_WITH_CODE (Seat, seat, G_TYPE_OBJECT,
  76                          G_IMPLEMENT_INTERFACE (
  77                              LOGGER_TYPE, seat_logger_iface_init));
  78
  79 typedef struct
  80 {
  81     gchar *name;
  82     GType type;
  83 } SeatModule;
  84 static GHashTable *seat_modules = NULL;
  85
  86 // FIXME: Make a get_display_server() that re-uses display servers if supported
  87 static DisplayServer *create_display_server (Seat *seat, Session *session);
  88 static gboolean start_display_server (Seat *seat, DisplayServer *display_server);
  89 static GreeterSession *create_greeter_session (Seat *seat);
  90 static void start_session (Seat *seat, Session *session);
  91
  92 static void
  93 free_seat_module (gpointer data)
  94 {
  95     SeatModule *module = data;
  96     g_free (module->name);
  97     g_free (module);
  98 }
  99
 100 void
 101 seat_register_module (const gchar *name, GType type)
 102 {
 103     SeatModule *module;
 104
 105     if (!seat_modules)
 106         seat_modules = g_hash_table_new_full (g_str_hash, g_str_equal, free_seat_module, NULL);
 107
 108     g_debug ("Registered seat module %s", name);
 109
 110     module = g_malloc0 (sizeof (SeatModule));
 111     module->name = g_strdup (name);
 112     module->type = type;
 113     g_hash_table_insert (seat_modules, g_strdup (name), module);
 114 }
 115
 116 Seat *
 117 seat_new (const gchar *module_name, const gchar *name)
 118 {
 119     Seat *seat;
 120     SeatModule *m = NULL;
 121
 122     g_return_val_if_fail (module_name != NULL, NULL);
 123
 124     if (seat_modules)
 125         m = g_hash_table_lookup (seat_modules, module_name);
 126     if (!m)
 127         return NULL;
 128
 129     seat = g_object_new (m->type, NULL);
 130     seat->priv->name = g_strdup (name);
 131
 132     return seat;
 133 }
 134
 135 void
 136 seat_set_property (Seat *seat, const gchar *name, const gchar *value)
 137 {
 138     g_return_if_fail (seat != NULL);
 139     g_hash_table_insert (seat->priv->properties, g_strdup (name), g_strdup (value));
 140 }
 141
 142 const gchar *
 143 seat_get_string_property (Seat *seat, const gchar *name)
 144 {
 145     g_return_val_if_fail (seat != NULL, NULL);
 146     return g_hash_table_lookup (seat->priv->properties, name);
 147 }
 148
 149 gchar **
 150 seat_get_string_list_property (Seat *seat, const gchar *name)
 151 {
 152     g_return_val_if_fail (seat != NULL, NULL);
 153     return g_strsplit (g_hash_table_lookup (seat->priv->properties, name), ";", 0);
 154 }
 155
 156 gboolean
 157 seat_get_boolean_property (Seat *seat, const gchar *name)
 158 {
 159     const gchar *value;
 160     gint i, length = 0;
 161
 162     value = seat_get_string_property (seat, name);
 163     if (!value)
 164         return FALSE;
 165
 166     /* Count the number of non-whitespace characters */
 167     for (i = 0; value[i]; i++)
 168         if (!g_ascii_isspace (value[i]))
 169             length = i + 1;
 170
 171     return strncmp (value, "true", MAX (length, 4)) == 0;
 172 }
 173
 174 gint
 175 seat_get_integer_property (Seat *seat, const gchar *name)
 176 {
 177     const gchar *value;
 178
 179     value = seat_get_string_property (seat, name);
 180     return value ? atoi (value) : 0;
 181 }
 182
 183 const gchar *
 184 seat_get_name (Seat *seat)
 185 {
 186     return seat->priv->name;
 187 }
 188
 189 void
 190 seat_set_supports_multi_session (Seat *seat, gboolean supports_multi_session)
 191 {
 192     g_return_if_fail (seat != NULL);
 193     seat->priv->supports_multi_session = supports_multi_session;
 194 }
 195
 196 void
 197 seat_set_share_display_server (Seat *seat, gboolean share_display_server)
 198 {
 199     g_return_if_fail (seat != NULL);
 200     seat->priv->share_display_server = share_display_server;
 201 }
 202
 203 gboolean
 204 seat_start (Seat *seat)
 205 {
 206     g_return_val_if_fail (seat != NULL, FALSE);
 207
 208     l_debug (seat, "Starting");
 209
 210     SEAT_GET_CLASS (seat)->setup (seat);
 211     seat->priv->started = SEAT_GET_CLASS (seat)->start (seat);
 212
 213     return seat->priv->started;
 214 }
 215
 216 GList *
 217 seat_get_sessions (Seat *seat)
 218 {
 219     g_return_val_if_fail (seat != NULL, NULL);
 220     return seat->priv->sessions;
 221 }
 222
 223 static gboolean
 224 set_greeter_idle (gpointer greeter)
 225 {
 226     greeter_idle (GREETER (greeter));
 227     return FALSE;
 228 }
 229
 230 void
 231 seat_set_active_session (Seat *seat, Session *session)
 232 {
 233     GList *link;
 234
 235     g_return_if_fail (seat != NULL);
 236
 237     SEAT_GET_CLASS (seat)->set_active_session (seat, session);
 238
 239     /* Stop any greeters */
 240     for (link = seat->priv->sessions; link; link = link->next)
 241     {
 242         Session *s = link->data;
 243
 244         if (s == session || session_get_is_stopping (s))
 245             continue;
 246
 247         if (IS_GREETER_SESSION (s))
 248         {
 249             Greeter *greeter = greeter_session_get_greeter (GREETER_SESSION (s));
 250             if (greeter_get_resettable (greeter))
 251             {
 252                 if (seat->priv->active_session == s)
 253                 {
 254                     l_debug (seat, "Idling greeter");
 255                     /* Do this in an idle callback, because we might very well
 256                        be in the middle of responding to a START_SESSION
 257                        request by a greeter.  So they won't expect an IDLE
 258                        call during that.  Plus, this isn't time-sensitive. */
 259                     g_idle_add (set_greeter_idle, greeter);
 260                 }
 261             }
 262             else
 263             {
 264                 l_debug (seat, "Stopping greeter");
 265                 session_stop (s);
 266             }
 267         }
 268     }
 269
 270     /* Lock previous sessions */
 271     if (seat->priv->active_session && session != seat->priv->active_session && !IS_GREETER_SESSION (seat->priv->active_session))
 272         session_lock (seat->priv->active_session);
 273
 274     session_activate (session);
 275     g_clear_object (&seat->priv->active_session);
 276     seat->priv->active_session = g_object_ref (session);
 277 }
 278
 279 Session *
 280 seat_get_active_session (Seat *seat)
 281 {
 282     g_return_val_if_fail (seat != NULL, NULL);
 283     return SEAT_GET_CLASS (seat)->get_active_session (seat);
 284 }
 285
 286 Session *
 287 seat_get_next_session (Seat *seat)
 288 {
 289     g_return_val_if_fail (seat != NULL, NULL);
 290     return seat->priv->next_session;
 291 }
 292
 293 /**
 294  * Obtains the active session which lightdm expects to be active.
 295  *
 296  * This function is different from seat_get_active_session() in that the
 297  * later (in the case of xlocal seats) dynamically finds the session that is
 298  * really active (based on the active VT), whereas this function returns the
 299  * session that lightdm activated last by itself, which may not be the actual
 300  * active session (i.e. VT changes).
 301  */
 302 Session *
 303 seat_get_expected_active_session (Seat *seat)
 304 {
 305     g_return_val_if_fail (seat != NULL, NULL);
 306     return seat->priv->active_session;
 307 }
 308
 309 /**
 310  * Sets the active session which lightdm expects to be active.
 311  *
 312  * This function is different from seat_set_active_session() in that the
 313  * later performs an actual session activation, whereas this function just
 314  * updates the active session after the session has been activated by some
 315  * means external to lightdm (i.e. VT changes).
 316  */
 317 void
 318 seat_set_externally_activated_session (Seat *seat, Session *session)
 319 {
 320     g_return_if_fail (seat != NULL);
 321     g_clear_object (&seat->priv->active_session);
 322     seat->priv->active_session = g_object_ref (session);
 323 }
 324
 325 Session *
 326 seat_find_session_by_login1_id (Seat *seat, const gchar *login1_session_id)
 327 {
 328     GList *session_link;
 329
 330     for (session_link = seat->priv->sessions; session_link; session_link = session_link->next)
 331     {
 332         Session *session = session_link->data;
 333         if (g_strcmp0 (login1_session_id, session_get_login1_session_id (session)) == 0)
 334             return session;
 335     }
 336
 337     return NULL;
 338 }
 339
 340 gboolean
 341 seat_get_can_switch (Seat *seat)
 342 {
 343     g_return_val_if_fail (seat != NULL, FALSE);
 344     return seat_get_boolean_property (seat, "allow-user-switching") && seat->priv->supports_multi_session;
 345 }
 346
 347 gboolean
 348 seat_get_allow_guest (Seat *seat)
 349 {
 350     g_return_val_if_fail (seat != NULL, FALSE);
 351     return seat_get_boolean_property (seat, "allow-guest") && guest_account_is_installed ();
 352 }
 353
 354 static gboolean
 355 run_script (Seat *seat, DisplayServer *display_server, const gchar *script_name, User *user)
 356 {
 357     Process *script;
 358     gboolean result = FALSE;
 359
 360     script = process_new (NULL, NULL);
 361
 362     process_set_command (script, script_name);
 363
 364     /* Set POSIX variables */
 365     process_set_clear_environment (script, TRUE);
 366     process_set_env (script, "SHELL", "/bin/sh");
 367
 368     /* Variables required for regression tests */
 369     if (g_getenv ("LIGHTDM_TEST_ROOT"))
 370     {
 371         process_set_env (script, "LIGHTDM_TEST_ROOT", g_getenv ("LIGHTDM_TEST_ROOT"));
 372         process_set_env (script, "LD_PRELOAD", g_getenv ("LD_PRELOAD"));
 373         process_set_env (script, "LD_LIBRARY_PATH", g_getenv ("LD_LIBRARY_PATH"));
 374         process_set_env (script, "PATH", g_getenv ("PATH"));
 375     }
 376     else
 377         process_set_env (script, "PATH", "/usr/local/bin:/usr/bin:/bin");
 378
 379     if (user)
 380     {
 381         process_set_env (script, "USER", user_get_name (user));
 382         process_set_env (script, "LOGNAME", user_get_name (user));
 383         process_set_env (script, "HOME", user_get_home_directory (user));
 384     }
 385     else
 386         process_set_env (script, "HOME", "/");
 387
 388     SEAT_GET_CLASS (seat)->run_script (seat, display_server, script);
 389
 390     if (process_start (script, TRUE))
 391     {
 392         int exit_status;
 393
 394         exit_status = process_get_exit_status (script);
 395         if (WIFEXITED (exit_status))
 396         {
 397             l_debug (seat, "Exit status of %s: %d", script_name, WEXITSTATUS (exit_status));
 398             result = WEXITSTATUS (exit_status) == EXIT_SUCCESS;
 399         }
 400     }
 401
 402     g_object_unref (script);
 403
 404     return result;
 405 }
 406
 407 static void
 408 seat_real_run_script (Seat *seat, DisplayServer *display_server, Process *process)
 409 {
 410 }
 411
 412 static void
 413 emit_upstart_signal (const gchar *signal)
 414 {
 415     g_return_if_fail (signal != NULL);
 416     g_return_if_fail (signal[0] != 0);
 417     GSubprocess *p;
 418
 419     if (getuid () != 0)
 420         return;
 421
 422     /* OK if it fails, probably not installed or not running upstart */
 423     p = g_subprocess_new (G_SUBPROCESS_FLAGS_STDERR_SILENCE, NULL, "initctl", "-q", "emit", signal, "DISPLAY_MANAGER=lightdm", NULL);
 424     g_object_unref (p);
 425 }
 426
 427 static void
 428 check_stopped (Seat *seat)
 429 {
 430     if (seat->priv->stopping &&
 431         !seat->priv->stopped &&
 432         g_list_length (seat->priv->display_servers) == 0 &&
 433         g_list_length (seat->priv->sessions) == 0)
 434     {
 435         seat->priv->stopped = TRUE;
 436         l_debug (seat, "Stopped");
 437         g_signal_emit (seat, signals[STOPPED], 0);
 438     }
 439 }
 440
 441 static void
 442 display_server_stopped_cb (DisplayServer *display_server, Seat *seat)
 443 {
 444     const gchar *script;
 445     GList *list, *link;
 446     Session *active_session;
 447
 448     l_debug (seat, "Display server stopped");
 449
 450     /* Run a script right after stopping the display server */
 451     script = seat_get_string_property (seat, "display-stopped-script");
 452     if (script)
 453         run_script (seat, NULL, script, NULL);
 454
 455     g_signal_handlers_disconnect_matched (display_server, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, seat);
 456     seat->priv->display_servers = g_list_remove (seat->priv->display_servers, display_server);
 457
 458     if (seat->priv->stopping || !seat->priv->started)
 459     {
 460         check_stopped (seat);
 461         g_object_unref (display_server);
 462         return;
 463     }
 464
 465     /* Stop all sessions on this display server */
 466     list = g_list_copy (seat->priv->sessions);
 467     for (link = list; link; link = link->next)
 468         g_object_ref (link->data);
 469     for (link = list; link; link = link->next)
 470     {
 471         Session *session = link->data;
 472
 473         if (session_get_display_server (session) != display_server || session_get_is_stopping (session))
 474             continue;
 475
 476         /* Stop seat if this is the only display server and it failed to start a greeter */
 477         if (IS_GREETER_SESSION (session) &&
 478             !session_get_is_started (session) &&
 479             g_list_length (seat->priv->display_servers) == 0)
 480         {
 481             l_debug (seat, "Stopping; greeter display server failed to start");
 482             seat_stop (seat);
 483         }
 484
 485         l_debug (seat, "Stopping session");
 486         session_stop (session);
 487     }
 488     g_list_free_full (list, g_object_unref);
 489
 490     if (!seat->priv->stopping)
 491     {
 492         /* If we were the active session, switch to a greeter */
 493         active_session = seat_get_active_session (seat);
 494         if (!active_session || session_get_display_server (active_session) == display_server)
 495         {
 496             l_debug (seat, "Active display server stopped, starting greeter");
 497             if (!seat_switch_to_greeter (seat))
 498             {
 499                 l_debug (seat, "Stopping; failed to start a greeter");
 500                 seat_stop (seat);
 501             }
 502         }
 503     }
 504
 505     g_object_unref (display_server);
 506 }
 507
 508 static gboolean
 509 can_share_display_server (Seat *seat, DisplayServer *display_server)
 510 {
 511     return seat->priv->share_display_server && display_server_get_can_share (display_server);
 512 }
 513
 514 static GreeterSession *
 515 find_greeter_session (Seat *seat)
 516 {
 517     GList *link;
 518
 519     for (link = seat->priv->sessions; link; link = link->next)
 520     {
 521         Session *session = link->data;
 522         if (!session_get_is_stopping (session) && IS_GREETER_SESSION (session))
 523             return GREETER_SESSION (session);
 524     }
 525
 526     return NULL;
 527 }
 528
 529 static GreeterSession *
 530 find_resettable_greeter (Seat *seat)
 531 {
 532     GList *link;
 533
 534     for (link = seat->priv->sessions; link; link = link->next)
 535     {
 536         Session *session = link->data;
 537         if (!session_get_is_stopping (session) && IS_GREETER_SESSION (session) &&
 538             greeter_get_resettable (greeter_session_get_greeter (GREETER_SESSION (session))))
 539             return GREETER_SESSION (session);
 540     }
 541
 542     return NULL;
 543 }
 544
 545 static void
 546 set_greeter_hints (Seat *seat, Greeter *greeter)
 547 {
 548     greeter_clear_hints (greeter);
 549     greeter_set_hint (greeter, "default-session", seat_get_string_property (seat, "user-session"));
 550     greeter_set_hint (greeter, "hide-users", seat_get_boolean_property (seat, "greeter-hide-users") ? "true" : "false");
 551     greeter_set_hint (greeter, "show-manual-login", seat_get_boolean_property (seat, "greeter-show-manual-login") ? "true" : "false");
 552     greeter_set_hint (greeter, "show-remote-login", seat_get_boolean_property (seat, "greeter-show-remote-login") ? "true" : "false");
 553     greeter_set_hint (greeter, "has-guest-account", seat_get_allow_guest (seat) && seat_get_boolean_property (seat, "greeter-allow-guest") ? "true" : "false");
 554 }
 555
 556 static void
 557 switch_to_greeter_from_failed_session (Seat *seat, Session *session)
 558 {
 559     GreeterSession *greeter_session;
 560     Greeter *greeter;
 561     gboolean existing = FALSE;
 562
 563     /* Switch to greeter if one open */
 564     greeter_session = find_resettable_greeter (seat);
 565     if (greeter_session)
 566     {
 567         l_debug (seat, "Switching to existing greeter");
 568         set_greeter_hints (seat, greeter_session_get_greeter (greeter_session));
 569         existing = TRUE;
 570     }
 571     else
 572     {
 573         greeter_session = create_greeter_session (seat);
 574     }
 575     greeter = greeter_session_get_greeter (greeter_session);
 576
 577     if (session_get_is_guest (session))
 578         greeter_set_hint (greeter, "select-guest", "true");
 579     else
 580         greeter_set_hint (greeter, "select-user", session_get_username (session));
 581
 582     if (existing)
 583     {
 584         greeter_reset (greeter);
 585         seat_set_active_session (seat, SESSION (greeter_session));
 586     }
 587     else
 588     {
 589         g_clear_object (&seat->priv->session_to_activate);
 590         seat->priv->session_to_activate = g_object_ref (greeter_session);
 591
 592         if (can_share_display_server (seat, session_get_display_server (session)))
 593             session_set_display_server (SESSION (greeter_session), session_get_display_server (session));
 594         else
 595         {
 596             DisplayServer *display_server;
 597
 598             display_server = create_display_server (seat, session);
 599             session_set_display_server (session, display_server);
 600             if (!start_display_server (seat, display_server))
 601             {
 602                 l_debug (seat, "Failed to start display server for greeter");
 603                 seat_stop (seat);
 604             }
 605         }
 606
 607         start_session (seat, SESSION (greeter_session));
 608     }
 609
 610     /* Stop failed session */
 611     session_stop (session);
 612 }
 613
 614 static void
 615 start_session (Seat *seat, Session *session)
 616 {
 617     /* Use system location for greeter log file */
 618     if (IS_GREETER_SESSION (session))
 619     {
 620         gchar *log_dir, *filename, *log_filename;
 621         gboolean backup_logs;
 622
 623         log_dir = config_get_string (config_get_instance (), "LightDM", "log-directory");
 624         filename = g_strdup_printf ("%s-greeter.log", display_server_get_name (session_get_display_server (session)));
 625         log_filename = g_build_filename (log_dir, filename, NULL);
 626         g_free (log_dir);
 627         g_free (filename);
 628         backup_logs = config_get_boolean (config_get_instance (), "LightDM", "backup-logs");
 629         session_set_log_file (session, log_filename, backup_logs ? LOG_MODE_BACKUP_AND_TRUNCATE : LOG_MODE_APPEND);
 630         g_free (log_filename);
 631     }
 632
 633     if (session_start (session))
 634         return;
 635
 636     if (IS_GREETER_SESSION (session))
 637     {
 638         l_debug (seat, "Failed to start greeter");
 639         display_server_stop (session_get_display_server (session));
 640         return;
 641     }
 642
 643     l_debug (seat, "Failed to start session, starting greeter");
 644     switch_to_greeter_from_failed_session (seat, session);
 645 }
 646
 647 static void
 648 run_session (Seat *seat, Session *session)
 649 {
 650     const gchar *script;
 651
 652     if (IS_GREETER_SESSION (session))
 653         script = seat_get_string_property (seat, "greeter-setup-script");
 654     else
 655         script = seat_get_string_property (seat, "session-setup-script");
 656     if (script && !run_script (seat, session_get_display_server (session), script, session_get_user (session)))
 657     {
 658         l_debug (seat, "Switching to greeter due to failed setup script");
 659         switch_to_greeter_from_failed_session (seat, session);
 660         return;
 661     }
 662
 663     if (!IS_GREETER_SESSION (session))
 664     {
 665         g_signal_emit (seat, signals[RUNNING_USER_SESSION], 0, session);
 666         emit_upstart_signal ("desktop-session-start");
 667     }
 668
 669     session_run (session);
 670
 671     // FIXME: Wait until the session is ready
 672
 673     if (session == seat->priv->session_to_activate)
 674     {
 675         seat_set_active_session (seat, session);
 676         g_clear_object (&seat->priv->session_to_activate);
 677     }
 678     else if (seat->priv->active_session)
 679     {
 680         /* Multiple sessions can theoretically be on the same VT (especially
 681            if using Mir).  If a new session appears on an existing active VT,
 682            logind will mark it as active, while ConsoleKit will re-mark the
 683            oldest session as active.  In either case, that may not be the
 684            session that we want to be active.  So let's be explicit and
 685            re-activate the correct session whenever a new session starts.
 686            There's no harm to do this in seats that enforce separate VTs. */
 687         session_activate (seat->priv->active_session);
 688     }
 689 }
 690
 691 static Session *
 692 find_user_session (Seat *seat, const gchar *username, Session *ignore_session)
 693 {
 694     GList *link;
 695
 696     if (!username)
 697         return NULL;
 698
 699     for (link = seat->priv->sessions; link; link = link->next)
 700     {
 701         Session *session = link->data;
 702
 703         if (session == ignore_session)
 704             continue;
 705
 706         if (!session_get_is_stopping (session) && g_strcmp0 (session_get_username (session), username) == 0)
 707             return session;
 708     }
 709
 710     return NULL;
 711 }
 712
 713 static void
 714 greeter_active_username_changed_cb (Greeter *greeter, GParamSpec *pspec, Seat *seat)
 715 {
 716     Session *session;
 717
 718     session = find_user_session (seat, greeter_get_active_username (greeter), seat->priv->active_session);
 719
 720     g_clear_object (&seat->priv->next_session);
 721     seat->priv->next_session = session ? g_object_ref (session) : NULL;
 722
 723     SEAT_GET_CLASS (seat)->set_next_session (seat, session);
 724 }
 725
 726 static void
 727 session_authentication_complete_cb (Session *session, Seat *seat)
 728 {
 729     if (session_get_is_authenticated (session))
 730     {
 731         Session *s;
 732
 733         s = find_user_session (seat, session_get_username (session), session);
 734         if (s)
 735         {
 736             l_debug (seat, "Session authenticated, switching to existing user session");
 737             seat_set_active_session (seat, s);
 738             session_stop (session);
 739         }
 740         else
 741         {
 742             l_debug (seat, "Session authenticated, running command");
 743             run_session (seat, session);
 744         }
 745     }
 746     else if (!IS_GREETER_SESSION (session))
 747     {
 748         l_debug (seat, "Switching to greeter due to failed authentication");
 749         switch_to_greeter_from_failed_session (seat, session);
 750     }
 751     else
 752     {
 753         l_debug (seat, "Stopping session that failed authentication");
 754         session_stop (session);
 755     }
 756 }
 757
 758 static void
 759 session_stopped_cb (Session *session, Seat *seat)
 760 {
 761     DisplayServer *display_server;
 762
 763     l_debug (seat, "Session stopped");
 764
 765     g_signal_handlers_disconnect_matched (session, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, seat);
 766     seat->priv->sessions = g_list_remove (seat->priv->sessions, session);
 767     if (session == seat->priv->active_session)
 768         g_clear_object (&seat->priv->active_session);
 769     if (session == seat->priv->next_session)
 770         g_clear_object (&seat->priv->next_session);
 771     if (session == seat->priv->session_to_activate)
 772         g_clear_object (&seat->priv->session_to_activate);
 773
 774     display_server = session_get_display_server (session);
 775     if (!display_server)
 776     {
 777         g_object_unref (session);
 778         return;
 779     }
 780
 781     /* Cleanup */
 782     if (!IS_GREETER_SESSION (session))
 783     {
 784         const gchar *script;
 785         script = seat_get_string_property (seat, "session-cleanup-script");
 786         if (script)
 787             run_script (seat, display_server, script, session_get_user (session));
 788     }
 789
 790     /* We were waiting for this session, but it didn't start :( */
 791     // FIXME: Start a greeter on this?
 792     if (session == seat->priv->session_to_activate)
 793         g_clear_object (&seat->priv->session_to_activate);
 794
 795     if (seat->priv->stopping)
 796     {
 797         check_stopped (seat);
 798         g_object_unref (session);
 799         return;
 800     }
 801
 802     /* If there is a pending replacement greeter, start it */
 803     if (IS_GREETER_SESSION (session) && seat->priv->replacement_greeter)
 804     {
 805         GreeterSession *replacement_greeter = seat->priv->replacement_greeter;
 806         seat->priv->replacement_greeter = NULL;
 807
 808         if (session_get_is_authenticated (SESSION (replacement_greeter)))
 809         {
 810             l_debug (seat, "Greeter stopped, running session");
 811             run_session (seat, SESSION (replacement_greeter));
 812         }
 813         else
 814         {
 815             l_debug (seat, "Greeter stopped, starting session authentication");
 816             start_session (seat, SESSION (replacement_greeter));
 817         }
 818
 819         g_object_unref (replacement_greeter);
 820     }
 821     /* If this is the greeter session then re-use this display server */
 822     else if (IS_GREETER_SESSION (session) &&
 823         can_share_display_server (seat, display_server) &&
 824         greeter_get_start_session (greeter_session_get_greeter (GREETER_SESSION (session))))
 825     {
 826         GList *link;
 827
 828         for (link = seat->priv->sessions; link; link = link->next)
 829         {
 830             Session *s = link->data;
 831
 832             /* Skip this session and sessions on other display servers */
 833             if (s == session || session_get_display_server (s) != display_server || session_get_is_stopping (s))
 834                 continue;
 835
 836             if (session_get_is_authenticated (s))
 837             {
 838                 l_debug (seat, "Greeter stopped, running session");
 839                 run_session (seat, s);
 840             }
 841             else
 842             {
 843                 l_debug (seat, "Greeter stopped, starting session authentication");
 844                 start_session (seat, s);
 845             }
 846             break;
 847         }
 848     }
 849     /* If this is the greeter and nothing else is running then stop the seat */
 850     else if (IS_GREETER_SESSION (session) &&
 851         !greeter_get_start_session (greeter_session_get_greeter (GREETER_SESSION (session))) &&
 852         g_list_length (seat->priv->display_servers) == 1 &&
 853         g_list_nth_data (seat->priv->display_servers, 0) == display_server)
 854     {
 855         l_debug (seat, "Stopping; failed to start a greeter");
 856         seat_stop (seat);
 857     }
 858     /* If we were the active session, switch to a greeter */
 859     else if (!IS_GREETER_SESSION (session) && session == seat_get_active_session (seat))
 860     {
 861         l_debug (seat, "Active session stopped, starting greeter");
 862         if (!seat_switch_to_greeter (seat))
 863         {
 864             l_debug (seat, "Stopping; failed to start a greeter");
 865             seat_stop (seat);
 866         }
 867     }
 868
 869     /* Stop the display server if no-longer required */
 870     if (display_server && !display_server_get_is_stopping (display_server) &&
 871         !SEAT_GET_CLASS (seat)->display_server_is_used (seat, display_server))
 872     {
 873         l_debug (seat, "Stopping display server, no sessions require it");
 874         display_server_stop (display_server);
 875     }
 876
 877     g_signal_emit (seat, signals[SESSION_REMOVED], 0, session);
 878     g_object_unref (session);
 879 }
 880
 881 static void
 882 set_session_env (Session *session)
 883 {
 884     /* Connect using the session bus */
 885     if (getuid () != 0)
 886     {
 887         if (g_getenv ("DBUS_SESSION_BUS_ADDRESS"))
 888             session_set_env (session, "DBUS_SESSION_BUS_ADDRESS", g_getenv ("DBUS_SESSION_BUS_ADDRESS"));
 889         session_set_env (session, "LDM_BUS", "SESSION");
 890         if (g_getenv ("LD_PRELOAD"))
 891             session_set_env (session, "LD_PRELOAD", g_getenv ("LD_PRELOAD"));
 892         if (g_getenv ("LD_LIBRARY_PATH"))
 893             session_set_env (session, "LD_LIBRARY_PATH", g_getenv ("LD_LIBRARY_PATH"));
 894         if (g_getenv ("PATH"))
 895             session_set_env (session, "PATH", g_getenv ("PATH"));
 896     }
 897
 898     /* Variables required for regression tests */
 899     if (g_getenv ("LIGHTDM_TEST_ROOT"))
 900     {
 901         session_set_env (session, "LIGHTDM_TEST_ROOT", g_getenv ("LIGHTDM_TEST_ROOT"));
 902         session_set_env (session, "DBUS_SYSTEM_BUS_ADDRESS", g_getenv ("DBUS_SYSTEM_BUS_ADDRESS"));
 903         session_set_env (session, "DBUS_SESSION_BUS_ADDRESS", g_getenv ("DBUS_SESSION_BUS_ADDRESS"));
 904         session_set_env (session, "LD_PRELOAD", g_getenv ("LD_PRELOAD"));
 905         session_set_env (session, "LD_LIBRARY_PATH", g_getenv ("LD_LIBRARY_PATH"));
 906         session_set_env (session, "GI_TYPELIB_PATH", g_getenv ("GI_TYPELIB_PATH"));
 907     }
 908 }
 909
 910 static Session *
 911 create_session (Seat *seat, gboolean autostart)
 912 {
 913     Session *session;
 914
 915     session = SEAT_GET_CLASS (seat)->create_session (seat);
 916     seat->priv->sessions = g_list_append (seat->priv->sessions, session);
 917     if (autostart)
 918         g_signal_connect (session, SESSION_SIGNAL_AUTHENTICATION_COMPLETE, G_CALLBACK (session_authentication_complete_cb), seat);
 919     g_signal_connect (session, SESSION_SIGNAL_STOPPED, G_CALLBACK (session_stopped_cb), seat);
 920
 921     set_session_env (session);
 922
 923     g_signal_emit (seat, signals[SESSION_ADDED], 0, session);
 924
 925     return session;
 926 }
 927
 928 static gchar **
 929 get_session_argv (Seat *seat, SessionConfig *session_config, const gchar *session_wrapper)
 930 {
 931     gboolean result;
 932     int argc;
 933     gchar **argv, *path;
 934     GError *error = NULL;
 935
 936     /* If configured, run sessions through a wrapper */
 937     if (session_wrapper)
 938     {
 939         argv = g_malloc (sizeof (gchar *) * 3);
 940         path = g_find_program_in_path (session_wrapper);
 941         argv[0] = path ? path : g_strdup (session_wrapper);
 942         argv[1] = g_strdup (session_config_get_command (session_config));
 943         argv[2] = NULL;
 944         return argv;
 945     }
 946
 947     /* Split command into an array listing and make command absolute */
 948     result = g_shell_parse_argv (session_config_get_command (session_config), &argc, &argv, &error);
 949     if (error)
 950         l_debug (seat, "Invalid session command '%s': %s", session_config_get_command (session_config), error->message);
 951     g_clear_error (&error);
 952     if (!result)
 953         return NULL;
 954     path = g_find_program_in_path (argv[0]);
 955     if (path)
 956     {
 957         g_free (argv[0]);
 958         argv[0] = path;
 959     }
 960
 961     return argv;
 962 }
 963
 964 static SessionConfig *
 965 find_session_config (Seat *seat, const gchar *sessions_dir, const gchar *session_name)
 966 {
 967     gchar **dirs;
 968     SessionConfig *session_config = NULL;
 969     int i;
 970     GError *error = NULL;
 971
 972     g_return_val_if_fail (sessions_dir != NULL, NULL);
 973     g_return_val_if_fail (session_name != NULL, NULL);
 974
 975     dirs = g_strsplit (sessions_dir, ":", -1);
 976     for (i = 0; dirs[i]; i++)
 977     {
 978         gchar *filename, *path;
 979         const gchar *default_session_type = "x";
 980
 981         if (strcmp (dirs[i], WAYLAND_SESSIONS_DIR) == 0)
 982             default_session_type = "wayland";
 983
 984         filename = g_strdup_printf ("%s.desktop", session_name);
 985         path = g_build_filename (dirs[i], filename, NULL);
 986         g_free (filename);
 987         session_config = session_config_new_from_file (path, default_session_type, &error);
 988         g_free (path);
 989         if (session_config)
 990             break;
 991
 992         if (dirs[i+1] == NULL)
 993             l_debug (seat, "Failed to find session configuration %s", session_name);
 994         g_clear_error (&error);
 995     }
 996     g_strfreev (dirs);
 997
 998     return session_config;
 999 }
1000
1001 static void
1002 configure_session (Session *session, SessionConfig *config, const gchar *session_name, const gchar *language)
1003 {
1004     gchar **desktop_names;
1005
1006     session_set_config (session, config);
1007     session_set_env (session, "XDG_SESSION_DESKTOP", session_name);
1008     session_set_env (session, "DESKTOP_SESSION", session_name);
1009     session_set_env (session, "GDMSESSION", session_name);
1010     desktop_names = session_config_get_desktop_names (config);
1011     if (desktop_names)
1012     {
1013         gchar *value;
1014         value = g_strjoinv (":", desktop_names);
1015         session_set_env (session, "XDG_CURRENT_DESKTOP", value);
1016         g_free (value);
1017     }
1018     if (language && language[0] != '\0')
1019     {
1020         session_set_env (session, "LANG", language);
1021         session_set_env (session, "GDM_LANG", language);
1022     }
1023 }
1024
1025 static Session *
1026 create_user_session (Seat *seat, const gchar *username, gboolean autostart)
1027 {
1028     User *user;
1029     gchar *sessions_dir;
1030     const gchar *session_name, *language;
1031     SessionConfig *session_config;
1032     Session *session = NULL;
1033
1034     l_debug (seat, "Creating user session");
1035
1036     /* Load user preferences */
1037     user = accounts_get_user_by_name (username);
1038     if (!user)
1039     {
1040         l_debug (seat, "Can't login unknown user '%s'", username);
1041         return NULL;
1042     }
1043     session_name = user_get_xsession (user);
1044     language = user_get_language (user);
1045
1046     /* Override session for autologin if configured */
1047     if (autostart)
1048     {
1049         const gchar *autologin_session_name = seat_get_string_property (seat, "autologin-session");
1050         if (autologin_session_name)
1051             session_name = autologin_session_name;
1052     }
1053
1054     if (!session_name)
1055         session_name = seat_get_string_property (seat, "user-session");
1056     sessions_dir = config_get_string (config_get_instance (), "LightDM", "sessions-directory");
1057     session_config = find_session_config (seat, sessions_dir, session_name);
1058     g_free (sessions_dir);
1059     if (session_config)
1060     {
1061         gchar **argv;
1062
1063         session = create_session (seat, autostart);
1064         configure_session (session, session_config, session_name, language);
1065         session_set_username (session, username);
1066         session_set_do_authenticate (session, TRUE);
1067         argv = get_session_argv (seat, session_config, seat_get_string_property (seat, "session-wrapper"));
1068         session_set_argv (session, argv);
1069         g_strfreev (argv);
1070         g_object_unref (session_config);
1071     }
1072     else
1073         l_debug (seat, "Can't find session '%s'", session_name);
1074
1075     g_object_unref (user);
1076
1077     return session;
1078 }
1079
1080 static void
1081 prepend_argv (gchar ***argv, const gchar *value)
1082 {
1083     gchar **old_argv, **new_argv;
1084     gint i;
1085
1086     old_argv = *argv;
1087     new_argv = g_malloc (sizeof (gchar *) * (g_strv_length (*argv) + 2));
1088     new_argv[0] = g_strdup (value);
1089     for (i = 0; old_argv[i]; i++)
1090         new_argv[i + 1] = old_argv[i];
1091     new_argv[i + 1] = NULL;
1092
1093     g_free (*argv);
1094     *argv = new_argv;
1095 }
1096
1097 static Session *
1098 create_guest_session (Seat *seat, const gchar *session_name)
1099 {
1100     const gchar *guest_wrapper;
1101     gchar *sessions_dir, **argv;
1102     SessionConfig *session_config;
1103     Session *session;
1104
1105     if (!session_name)
1106         session_name = seat_get_string_property (seat, "guest-session");
1107     if (!session_name)
1108         session_name = seat_get_string_property (seat, "user-session");
1109     sessions_dir = config_get_string (config_get_instance (), "LightDM", "sessions-directory");
1110     session_config = find_session_config (seat, sessions_dir, session_name);
1111     g_free (sessions_dir);
1112     if (!session_config)
1113     {
1114         l_debug (seat, "Can't find session '%s'", session_name);
1115         return NULL;
1116     }
1117
1118     session = create_session (seat, TRUE);
1119     configure_session (session, session_config, session_name, NULL);
1120     session_set_do_authenticate (session, TRUE);
1121     session_set_is_guest (session, TRUE);
1122     argv = get_session_argv (seat, session_config, seat_get_string_property (seat, "session-wrapper"));
1123     guest_wrapper = seat_get_string_property (seat, "guest-wrapper");
1124     if (guest_wrapper)
1125     {
1126         gchar *path;
1127         path = g_find_program_in_path (guest_wrapper);
1128         prepend_argv (&argv, path ? path : guest_wrapper);
1129         g_free (path);
1130     }
1131
1132     session_set_argv (session, argv);
1133     g_strfreev (argv);
1134     g_object_unref (session_config);
1135
1136     return session;
1137 }
1138
1139 // FIXME: This is inefficient and we already know the greeter session when we set the callbacks...
1140 static Session *
1141 get_greeter_session (Seat *seat, Greeter *greeter)
1142 {
1143     GList *link;
1144
1145     /* Stop any greeters */
1146     for (link = seat->priv->sessions; link; link = link->next)
1147     {
1148         Session *session = link->data;
1149
1150         if (IS_GREETER_SESSION (session) && greeter_session_get_greeter (GREETER_SESSION (session)))
1151             return session;
1152     }
1153
1154     return NULL;
1155 }
1156
1157 static Session *
1158 greeter_create_session_cb (Greeter *greeter, Seat *seat)
1159 {
1160     Session *greeter_session, *session;
1161
1162     greeter_session = get_greeter_session (seat, greeter);
1163     session = create_session (seat, FALSE);
1164     session_set_config (session, session_get_config (greeter_session));
1165     session_set_display_server (session, session_get_display_server (greeter_session));
1166
1167     return g_object_ref (session);
1168 }
1169
1170 static gboolean
1171 greeter_start_session_cb (Greeter *greeter, SessionType type, const gchar *session_name, Seat *seat)
1172 {
1173     Session *session, *existing_session, *greeter_session;
1174     const gchar *username;
1175     DisplayServer *display_server;
1176
1177     /* Get the session to use */
1178     if (greeter_get_guest_authenticated (greeter))
1179     {
1180         session = create_guest_session (seat, session_name);
1181         if (!session)
1182             return FALSE;
1183         session_set_pam_service (session, seat_get_string_property (seat, "pam-autologin-service"));
1184     }
1185     else
1186     {
1187         const gchar *language = NULL;
1188         SessionConfig *session_config;
1189         User *user;
1190         gchar *sessions_dir = NULL;
1191         gchar **argv;
1192
1193         session = greeter_get_authentication_session (greeter);
1194
1195         /* Get session command to run */
1196         switch (type)
1197         {
1198         case SESSION_TYPE_LOCAL:
1199             sessions_dir = config_get_string (config_get_instance (), "LightDM", "sessions-directory");
1200             break;
1201         case SESSION_TYPE_REMOTE:
1202             sessions_dir = config_get_string (config_get_instance (), "LightDM", "remote-sessions-directory");
1203             break;
1204         }
1205
1206         /* Load user preferences */
1207         user = session_get_user (session);
1208         if (user)
1209         {
1210             if (!session_name)
1211                 session_name = user_get_xsession (user);
1212             language = user_get_language (user);
1213         }
1214
1215         if (!session_name)
1216             session_name = seat_get_string_property (seat, "user-session");
1217         if (user)
1218             user_set_xsession (session_get_user (session), session_name);
1219
1220         session_config = find_session_config (seat, sessions_dir, session_name);
1221         g_free (sessions_dir);
1222         if (!session_config)
1223         {
1224             l_debug (seat, "Can't find session '%s'", session_name);
1225             return FALSE;
1226         }
1227
1228         configure_session (session, session_config, session_name, language);
1229         argv = get_session_argv (seat, session_config, seat_get_string_property (seat, "session-wrapper"));
1230         session_set_argv (session, argv);
1231         g_strfreev (argv);
1232         g_object_unref (session_config);
1233     }
1234
1235     /* Switch to this session when it is ready */
1236     g_clear_object (&seat->priv->session_to_activate);
1237     seat->priv->session_to_activate = g_object_ref (session);
1238
1239     /* Return to existing session if it is open */
1240     username = session_get_username (session);
1241     existing_session = find_user_session (seat, username, NULL);
1242     if (existing_session && session != existing_session)
1243     {
1244         l_debug (seat, "Returning to existing user session %s", username);
1245         session_stop (session);
1246         session_unlock (existing_session);
1247         seat_set_active_session (seat, existing_session);
1248         return TRUE;
1249     }
1250
1251     /* If can re-use the display server, stop the greeter first */
1252     greeter_session = get_greeter_session (seat, greeter);
1253     display_server = session_get_display_server (greeter_session);
1254     if (!greeter_get_resettable (greeter) &&
1255         can_share_display_server (seat, display_server) &&
1256         strcmp (display_server_get_session_type (display_server), session_get_session_type (session)) == 0)
1257     {
1258         l_debug (seat, "Stopping greeter; display server will be re-used for user session");
1259
1260         /* Run on the same display server after the greeter has stopped */
1261         session_set_display_server (session, display_server);
1262
1263         /* Stop the greeter */
1264         session_stop (greeter_session);
1265
1266         return TRUE;
1267     }
1268     /* Otherwise start a new display server for this session */
1269     else
1270     {
1271         display_server = create_display_server (seat, session);
1272         session_set_display_server (session, display_server);
1273         if (!start_display_server (seat, display_server))
1274         {
1275             l_debug (seat, "Failed to start display server for new session");
1276             return FALSE;
1277         }
1278
1279         return TRUE;
1280     }
1281 }
1282
1283 static GreeterSession *
1284 create_greeter_session (Seat *seat)
1285 {
1286     gchar *sessions_dir, **argv;
1287     SessionConfig *session_config;
1288     GreeterSession *greeter_session;
1289     Greeter *greeter;
1290     const gchar *greeter_wrapper;
1291     const gchar *autologin_username;
1292     int autologin_timeout;
1293     gboolean autologin_guest;
1294
1295     l_debug (seat, "Creating greeter session");
1296
1297     sessions_dir = config_get_string (config_get_instance (), "LightDM", "greeters-directory");
1298     session_config = find_session_config (seat, sessions_dir, seat_get_string_property (seat, "greeter-session"));
1299     g_free (sessions_dir);
1300     if (!session_config)
1301         return NULL;
1302
1303     argv = get_session_argv (seat, session_config, NULL);
1304     greeter_wrapper = seat_get_string_property (seat, "greeter-wrapper");
1305     if (greeter_wrapper)
1306     {
1307         gchar *path;
1308         path = g_find_program_in_path (greeter_wrapper);
1309         prepend_argv (&argv, path ? path : greeter_wrapper);
1310         g_free (path);
1311     }
1312
1313     greeter_session = SEAT_GET_CLASS (seat)->create_greeter_session (seat);
1314     greeter = greeter_session_get_greeter (greeter_session);
1315     session_set_config (SESSION (greeter_session), session_config);
1316     seat->priv->sessions = g_list_append (seat->priv->sessions, SESSION (greeter_session));
1317     g_signal_connect (greeter, GREETER_SIGNAL_ACTIVE_USERNAME_CHANGED, G_CALLBACK (greeter_active_username_changed_cb), seat);
1318     g_signal_connect (greeter_session, SESSION_SIGNAL_AUTHENTICATION_COMPLETE, G_CALLBACK (session_authentication_complete_cb), seat);
1319     g_signal_connect (greeter_session, SESSION_SIGNAL_STOPPED, G_CALLBACK (session_stopped_cb), seat);
1320
1321     set_session_env (SESSION (greeter_session));
1322     session_set_env (SESSION (greeter_session), "XDG_SESSION_CLASS", "greeter");
1323
1324     session_set_pam_service (SESSION (greeter_session), seat_get_string_property (seat, "pam-greeter-service"));
1325     if (getuid () == 0)
1326     {
1327         gchar *greeter_user;
1328         greeter_user = config_get_string (config_get_instance (), "LightDM", "greeter-user");
1329         session_set_username (SESSION (greeter_session), greeter_user);
1330         g_free (greeter_user);
1331     }
1332     else
1333     {
1334         /* In test mode run the greeter as ourself */
1335         session_set_username (SESSION (greeter_session), user_get_name (accounts_get_current_user ()));
1336     }
1337     session_set_argv (SESSION (greeter_session), argv);
1338     g_strfreev (argv);
1339
1340     greeter_set_pam_services (greeter,
1341                               seat_get_string_property (seat, "pam-service"),
1342                               seat_get_string_property (seat, "pam-autologin-service"));
1343     g_signal_connect (greeter, GREETER_SIGNAL_CREATE_SESSION, G_CALLBACK (greeter_create_session_cb), seat);
1344     g_signal_connect (greeter, GREETER_SIGNAL_START_SESSION, G_CALLBACK (greeter_start_session_cb), seat);
1345
1346     /* Set hints to greeter */
1347     greeter_set_allow_guest (greeter, seat_get_allow_guest (seat));
1348     set_greeter_hints (seat, greeter);
1349
1350     /* Configure for automatic login */
1351     autologin_username = seat_get_string_property (seat, "autologin-user");
1352     if (g_strcmp0 (autologin_username, "") == 0)
1353         autologin_username = NULL;
1354     autologin_timeout = seat_get_integer_property (seat, "autologin-user-timeout");
1355     autologin_guest = seat_get_boolean_property (seat, "autologin-guest");
1356     if (autologin_timeout > 0)
1357     {
1358         gchar *value;
1359
1360         value = g_strdup_printf ("%d", autologin_timeout);
1361         greeter_set_hint (greeter, "autologin-timeout", value);
1362         g_free (value);
1363         if (autologin_username)
1364             greeter_set_hint (greeter, "autologin-user", autologin_username);
1365         if (autologin_guest)
1366             greeter_set_hint (greeter, "autologin-guest", "true");
1367     }
1368
1369     g_object_unref (session_config);
1370
1371     return greeter_session;
1372 }
1373
1374 static Session *
1375 find_session_for_display_server (Seat *seat, DisplayServer *display_server)
1376 {
1377     GList *link;
1378
1379     for (link = seat->priv->sessions; link; link = link->next)
1380     {
1381         Session *session = link->data;
1382
1383         if (session_get_display_server (session) == display_server &&
1384             !session_get_is_stopping (session) &&
1385             !session_get_is_run (session))
1386             return session;
1387     }
1388
1389     return NULL;
1390 }
1391
1392 static void
1393 display_server_ready_cb (DisplayServer *display_server, Seat *seat)
1394 {
1395     const gchar *script;
1396     Session *session;
1397
1398     /* Run setup script */
1399     script = seat_get_string_property (seat, "display-setup-script");
1400     if (script && !run_script (seat, display_server, script, NULL))
1401     {
1402         l_debug (seat, "Stopping display server due to failed setup script");
1403         display_server_stop (display_server);
1404         return;
1405     }
1406
1407     emit_upstart_signal ("login-session-start");
1408
1409     /* Start the session waiting for this display server */
1410     session = find_session_for_display_server (seat, display_server);
1411     if (session)
1412     {
1413         if (session_get_is_authenticated (session))
1414         {
1415             l_debug (seat, "Display server ready, running session");
1416             run_session (seat, session);
1417         }
1418         else
1419         {
1420             l_debug (seat, "Display server ready, starting session authentication");
1421             start_session (seat, session);
1422         }
1423     }
1424     else
1425     {
1426         l_debug (seat, "Stopping not required display server");
1427         display_server_stop (display_server);
1428     }
1429 }
1430
1431 static DisplayServer *
1432 create_display_server (Seat *seat, Session *session)
1433 {
1434     DisplayServer *display_server;
1435
1436     l_debug (seat, "Creating display server of type %s", session_get_session_type (session));
1437
1438     display_server = SEAT_GET_CLASS (seat)->create_display_server (seat, session);
1439     if (!display_server)
1440         return NULL;
1441
1442     /* Remember this display server */
1443     if (!g_list_find (seat->priv->display_servers, display_server))
1444     {
1445         seat->priv->display_servers = g_list_append (seat->priv->display_servers, display_server);
1446         g_signal_connect (display_server, DISPLAY_SERVER_SIGNAL_READY, G_CALLBACK (display_server_ready_cb), seat);
1447         g_signal_connect (display_server, DISPLAY_SERVER_SIGNAL_STOPPED, G_CALLBACK (display_server_stopped_cb), seat);
1448     }
1449
1450     return display_server;
1451 }
1452
1453 static gboolean
1454 start_display_server (Seat *seat, DisplayServer *display_server)
1455 {
1456     if (display_server_get_is_ready (display_server))
1457     {
1458         display_server_ready_cb (display_server, seat);
1459         return TRUE;
1460     }
1461     else
1462         return display_server_start (display_server);
1463 }
1464
1465 gboolean
1466 seat_switch_to_greeter (Seat *seat)
1467 {
1468     GreeterSession *greeter_session;
1469     DisplayServer *display_server;
1470
1471     g_return_val_if_fail (seat != NULL, FALSE);
1472
1473     if (!seat_get_can_switch (seat))
1474         return FALSE;
1475
1476     /* Switch to greeter if one open */
1477     greeter_session = find_greeter_session (seat);
1478     if (greeter_session)
1479     {
1480         l_debug (seat, "Switching to existing greeter");
1481         seat_set_active_session (seat, SESSION (greeter_session));
1482         return TRUE;
1483     }
1484
1485     greeter_session = create_greeter_session (seat);
1486     if (!greeter_session)
1487         return FALSE;
1488
1489     g_clear_object (&seat->priv->session_to_activate);
1490     seat->priv->session_to_activate = g_object_ref (greeter_session);
1491
1492     display_server = create_display_server (seat, SESSION (greeter_session));
1493     session_set_display_server (SESSION (greeter_session), display_server);
1494
1495     return start_display_server (seat, display_server);
1496 }
1497
1498 static void
1499 switch_authentication_complete_cb (Session *session, Seat *seat)
1500 {
1501     GreeterSession *greeter_session;
1502     Greeter *greeter;
1503     DisplayServer *display_server;
1504     gboolean existing = FALSE;
1505
1506     /* If authenticated, then unlock existing session or start new one */
1507     if (session_get_is_authenticated (session))
1508     {
1509         Session *s;
1510
1511         s = find_user_session (seat, session_get_username (session), session);
1512         if (s)
1513         {
1514             l_debug (seat, "Session authenticated, switching to existing user session");
1515             session_unlock (s);
1516             seat_set_active_session (seat, s);
1517             session_stop (session);
1518         }
1519         else
1520         {
1521             l_debug (seat, "Session authenticated, starting display server");
1522             g_clear_object (&seat->priv->session_to_activate);
1523             seat->priv->session_to_activate = g_object_ref (session);
1524             display_server = create_display_server (seat, session);
1525             session_set_display_server (session, display_server);
1526             start_display_server (seat, display_server);
1527         }
1528
1529         return;
1530     }
1531
1532     session_stop (session);
1533
1534     /* See if we already have a greeter up and reuse it if so */
1535     greeter_session = find_resettable_greeter (seat);
1536     if (greeter_session)
1537     {
1538         l_debug (seat, "Switching to existing greeter to authenticate session");
1539         set_greeter_hints (seat, greeter_session_get_greeter (greeter_session));
1540         existing = TRUE;
1541     }
1542     else
1543     {
1544         l_debug (seat, "Starting greeter to authenticate session");
1545         greeter_session = create_greeter_session (seat);
1546     }
1547     greeter = greeter_session_get_greeter (greeter_session);
1548
1549     if (session_get_is_guest (session))
1550         greeter_set_hint (greeter, "select-guest", "true");
1551     else
1552         greeter_set_hint (greeter, "select-user", session_get_username (session));
1553
1554     if (existing)
1555     {
1556         greeter_reset (greeter);
1557         seat_set_active_session (seat, SESSION (greeter_session));
1558     }
1559     else
1560     {
1561         g_clear_object (&seat->priv->session_to_activate);
1562         seat->priv->session_to_activate = g_object_ref (greeter_session);
1563
1564         display_server = create_display_server (seat, SESSION (greeter_session));
1565         session_set_display_server (SESSION (greeter_session), display_server);
1566         start_display_server (seat, display_server);
1567     }
1568 }
1569
1570 gboolean
1571 seat_switch_to_user (Seat *seat, const gchar *username, const gchar *session_name)
1572 {
1573     Session *session;
1574
1575     g_return_val_if_fail (seat != NULL, FALSE);
1576     g_return_val_if_fail (username != NULL, FALSE);
1577
1578     if (!seat_get_can_switch (seat))
1579         return FALSE;
1580
1581     /* If we're already on this session, then ignore */
1582     session = find_user_session (seat, username, NULL);
1583     if (session && session == seat->priv->active_session)
1584         return TRUE;
1585
1586     l_debug (seat, "Switching to user %s", username);
1587
1588     /* Attempt to authenticate them */
1589     session = create_user_session (seat, username, FALSE);
1590     g_signal_connect (session, SESSION_SIGNAL_AUTHENTICATION_COMPLETE, G_CALLBACK (switch_authentication_complete_cb), seat);
1591     session_set_pam_service (session, seat_get_string_property (seat, "pam-service"));
1592
1593     return session_start (session);
1594 }
1595
1596 static Session *
1597 find_guest_session (Seat *seat)
1598 {
1599     GList *link;
1600
1601     for (link = seat->priv->sessions; link; link = link->next)
1602     {
1603         Session *session = link->data;
1604         if (!session_get_is_stopping (session) && session_get_is_guest (session))
1605             return session;
1606     }
1607
1608     return NULL;
1609 }
1610
1611 gboolean
1612 seat_switch_to_guest (Seat *seat, const gchar *session_name)
1613 {
1614     Session *session;
1615     DisplayServer *display_server;
1616
1617     g_return_val_if_fail (seat != NULL, FALSE);
1618
1619     if (!seat_get_can_switch (seat) || !seat_get_allow_guest (seat))
1620         return FALSE;
1621
1622     /* Switch to session if one open */
1623     session = find_guest_session (seat);
1624     if (session)
1625     {
1626         l_debug (seat, "Switching to existing guest account %s", session_get_username (session));
1627         seat_set_active_session (seat, session);
1628         return TRUE;
1629     }
1630
1631     session = create_guest_session (seat, session_name);
1632     if (!session)
1633         return FALSE;
1634
1635     display_server = create_display_server (seat, session);
1636
1637     g_clear_object (&seat->priv->session_to_activate);
1638     seat->priv->session_to_activate = g_object_ref (session);
1639     session_set_pam_service (session, seat_get_string_property (seat, "pam-autologin-service"));
1640     session_set_display_server (session, display_server);
1641
1642     return start_display_server (seat, display_server);
1643 }
1644
1645 gboolean
1646 seat_lock (Seat *seat, const gchar *username)
1647 {
1648     GreeterSession *greeter_session;
1649     Greeter *greeter;
1650     DisplayServer *display_server = NULL;
1651     gboolean reset_existing = FALSE;
1652     gboolean reuse_xserver = FALSE;
1653
1654     g_return_val_if_fail (seat != NULL, FALSE);
1655
1656     if (!seat_get_can_switch (seat))
1657         return FALSE;
1658
1659     // FIXME: If already locked then don't bother...
1660
1661     l_debug (seat, "Locking");
1662
1663     /* Switch to greeter we can reuse */
1664     greeter_session = find_resettable_greeter (seat);
1665     if (greeter_session)
1666     {
1667         l_debug (seat, "Switching to existing greeter");
1668         set_greeter_hints (seat, greeter_session_get_greeter (greeter_session));
1669         reset_existing = TRUE;
1670     }
1671     else
1672     {
1673         /* If the existing greeter can't be reused, stop it and reuse its display server */
1674         greeter_session = find_greeter_session (seat);
1675         if (greeter_session)
1676         {
1677             display_server = session_get_display_server (SESSION (greeter_session));
1678             if (!session_get_is_stopping (SESSION (greeter_session)))
1679             {
1680                 l_debug (seat, "Stopping session");
1681                 session_stop (SESSION (greeter_session));
1682             }
1683             reuse_xserver = TRUE;
1684         }
1685
1686         greeter_session = create_greeter_session (seat);
1687         if (!greeter_session)
1688             return FALSE;
1689     }
1690     greeter = greeter_session_get_greeter (greeter_session);
1691
1692     greeter_set_hint (greeter, "lock-screen", "true");
1693     if (username)
1694         greeter_set_hint (greeter, "select-user", username);
1695
1696     if (reset_existing)
1697     {
1698         greeter_reset (greeter);
1699         seat_set_active_session (seat, SESSION (greeter_session));
1700         return TRUE;
1701     }
1702     else
1703     {
1704         if (!reuse_xserver)
1705             display_server = create_display_server (seat, SESSION (greeter_session));
1706         session_set_display_server (SESSION (greeter_session), display_server);
1707
1708         g_clear_object (&seat->priv->session_to_activate);
1709         seat->priv->session_to_activate = g_object_ref (greeter_session);
1710
1711         if (reuse_xserver)
1712         {
1713             g_clear_object (&seat->priv->replacement_greeter);
1714             seat->priv->replacement_greeter = g_object_ref (greeter_session);
1715             return TRUE;
1716         }
1717         else
1718             return start_display_server (seat, display_server);
1719     }
1720 }
1721
1722 void
1723 seat_stop (Seat *seat)
1724 {
1725     g_return_if_fail (seat != NULL);
1726
1727     if (seat->priv->stopping)
1728         return;
1729
1730     l_debug (seat, "Stopping");
1731     seat->priv->stopping = TRUE;
1732     SEAT_GET_CLASS (seat)->stop (seat);
1733 }
1734
1735 gboolean
1736 seat_get_is_stopping (Seat *seat)
1737 {
1738     g_return_val_if_fail (seat != NULL, FALSE);
1739     return seat->priv->stopping;
1740 }
1741
1742 static void
1743 seat_real_setup (Seat *seat)
1744 {
1745 }
1746
1747 static gboolean
1748 seat_real_start (Seat *seat)
1749 {
1750     const gchar *autologin_username;
1751     int autologin_timeout;
1752     gboolean autologin_guest;
1753     gboolean autologin_in_background;
1754     Session *session = NULL, *background_session = NULL;
1755
1756     /* Get autologin settings */
1757     autologin_username = seat_get_string_property (seat, "autologin-user");
1758     if (g_strcmp0 (autologin_username, "") == 0)
1759         autologin_username = NULL;
1760     autologin_timeout = seat_get_integer_property (seat, "autologin-user-timeout");
1761     autologin_guest = seat_get_boolean_property (seat, "autologin-guest");
1762     autologin_in_background = seat_get_boolean_property (seat, "autologin-in-background");
1763
1764     /* Autologin if configured */
1765     if (autologin_timeout == 0 || autologin_in_background)
1766     {
1767         if (autologin_guest)
1768             session = create_guest_session (seat, NULL);
1769         else if (autologin_username != NULL)
1770             session = create_user_session (seat, autologin_username, TRUE);
1771
1772         if (session)
1773             session_set_pam_service (session, seat_get_string_property (seat, "pam-autologin-service"));
1774
1775         /* Load in background if required */
1776         if (autologin_in_background && session)
1777         {
1778             background_session = session;
1779             session = NULL;
1780         }
1781
1782         if (session)
1783         {
1784             DisplayServer *display_server;
1785
1786             g_clear_object (&seat->priv->session_to_activate);
1787             seat->priv->session_to_activate = g_object_ref (session);
1788
1789             display_server = create_display_server (seat, session);
1790             session_set_display_server (session, display_server);
1791             if (!display_server || !start_display_server (seat, display_server))
1792             {
1793                 l_debug (seat, "Can't create display server for automatic login");
1794                 session_stop (session);
1795                 if (display_server)
1796                     display_server_stop (display_server);
1797                 session = NULL;
1798             }
1799         }
1800     }
1801
1802     /* Fallback to a greeter */
1803     if (!session)
1804     {
1805         GreeterSession *greeter_session;
1806         DisplayServer *display_server;
1807
1808         greeter_session = create_greeter_session (seat);
1809         if (!greeter_session)
1810         {
1811             l_debug (seat, "Failed to create greeter session");
1812             return FALSE;
1813         }
1814
1815         g_clear_object (&seat->priv->session_to_activate);
1816         seat->priv->session_to_activate = g_object_ref (greeter_session);
1817         session = SESSION (greeter_session);
1818
1819         display_server = create_display_server (seat, session);
1820         session_set_display_server (session, display_server);
1821         if (!display_server || !start_display_server (seat, display_server))
1822         {
1823             l_debug (seat, "Can't create display server for greeter");
1824             session_stop (session);
1825             if (display_server)
1826                 display_server_stop (display_server);
1827             session = NULL;
1828         }
1829     }
1830
1831     /* Fail if can't start a session */
1832     if (!session)
1833     {
1834         seat_stop (seat);
1835         return FALSE;
1836     }
1837
1838     /* Start background session */
1839     if (background_session)
1840     {
1841         DisplayServer *background_display_server;
1842
1843         background_display_server = create_display_server (seat, background_session);
1844         session_set_display_server (background_session, background_display_server);
1845         if (!start_display_server (seat, background_display_server))
1846             l_warning (seat, "Failed to start display server for background session");
1847     }
1848
1849     return TRUE;
1850 }
1851
1852 static DisplayServer *
1853 seat_real_create_display_server (Seat *seat, Session *session)
1854 {
1855     return NULL;
1856 }
1857
1858 static gboolean
1859 seat_real_display_server_is_used (Seat *seat, DisplayServer *display_server)
1860 {
1861     GList *link;
1862
1863     for (link = seat->priv->sessions; link; link = link->next)
1864     {
1865         Session *session = link->data;
1866         DisplayServer *d;
1867
1868         d = session_get_display_server (session);
1869         if (d == display_server || display_server_get_parent (d) == display_server)
1870             return TRUE;
1871     }
1872
1873     return FALSE;
1874 }
1875
1876 static GreeterSession *
1877 seat_real_create_greeter_session (Seat *seat)
1878 {
1879     return greeter_session_new ();
1880 }
1881
1882 static Session *
1883 seat_real_create_session (Seat *seat)
1884 {
1885     return session_new ();
1886 }
1887
1888 static void
1889 seat_real_set_active_session (Seat *seat, Session *session)
1890 {
1891 }
1892
1893 static void
1894 seat_real_set_next_session (Seat *seat, Session *session)
1895 {
1896 }
1897
1898 static Session *
1899 seat_real_get_active_session (Seat *seat)
1900 {
1901     return NULL;
1902 }
1903
1904 static void
1905 seat_real_stop (Seat *seat)
1906 {
1907     GList *list, *link;
1908
1909     check_stopped (seat);
1910     if (seat->priv->stopped)
1911         return;
1912
1913     /* Stop all the display servers and sessions on the seat. Copy the list as
1914      * it might be modified if a display server / session stops during this loop */
1915     list = g_list_copy (seat->priv->display_servers);
1916     for (link = list; link; link = link->next)
1917         g_object_ref (link->data);
1918     for (link = list; link; link = link->next)
1919     {
1920         DisplayServer *display_server = link->data;
1921         if (!display_server_get_is_stopping (display_server))
1922         {
1923             l_debug (seat, "Stopping display server");
1924             display_server_stop (display_server);
1925         }
1926     }
1927     g_list_free_full (list, g_object_unref);
1928     list = g_list_copy (seat->priv->sessions);
1929     for (link = list; link; link = link->next)
1930         g_object_ref (link->data);
1931     for (link = list; link; link = link->next)
1932     {
1933         Session *session = link->data;
1934         if (!session_get_is_stopping (session))
1935         {
1936             l_debug (seat, "Stopping session");
1937             session_stop (session);
1938         }
1939     }
1940     g_list_free_full (list, g_object_unref);
1941 }
1942
1943 static void
1944 seat_init (Seat *seat)
1945 {
1946     seat->priv = G_TYPE_INSTANCE_GET_PRIVATE (seat, SEAT_TYPE, SeatPrivate);
1947     seat->priv->properties = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
1948     seat->priv->share_display_server = TRUE;
1949 }
1950
1951 static void
1952 seat_finalize (GObject *object)
1953 {
1954     Seat *self = SEAT (object);
1955     GList *link;
1956
1957     g_free (self->priv->name);
1958     g_hash_table_unref (self->priv->properties);
1959     for (link = self->priv->display_servers; link; link = link->next)
1960     {
1961         DisplayServer *display_server = link->data;
1962         g_signal_handlers_disconnect_matched (display_server, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, self);
1963     }
1964     g_list_free_full (self->priv->display_servers, g_object_unref);
1965     for (link = self->priv->sessions; link; link = link->next)
1966     {
1967         Session *session = link->data;
1968         g_signal_handlers_disconnect_matched (session, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, self);
1969     }
1970     g_list_free_full (self->priv->sessions, g_object_unref);
1971     g_clear_object (&self->priv->active_session);
1972     g_clear_object (&self->priv->next_session);
1973     g_clear_object (&self->priv->session_to_activate);
1974     g_clear_object (&self->priv->replacement_greeter);
1975
1976     G_OBJECT_CLASS (seat_parent_class)->finalize (object);
1977 }
1978
1979 static void
1980 seat_class_init (SeatClass *klass)
1981 {
1982     GObjectClass *object_class = G_OBJECT_CLASS (klass);
1983
1984     klass->setup = seat_real_setup;
1985     klass->start = seat_real_start;
1986     klass->create_display_server = seat_real_create_display_server;
1987     klass->display_server_is_used = seat_real_display_server_is_used;
1988     klass->create_greeter_session = seat_real_create_greeter_session;
1989     klass->create_session = seat_real_create_session;
1990     klass->set_active_session = seat_real_set_active_session;
1991     klass->get_active_session = seat_real_get_active_session;
1992     klass->set_next_session = seat_real_set_next_session;
1993     klass->run_script = seat_real_run_script;
1994     klass->stop = seat_real_stop;
1995
1996     object_class->finalize = seat_finalize;
1997
1998     g_type_class_add_private (klass, sizeof (SeatPrivate));
1999
2000     signals[SESSION_ADDED] =
2001         g_signal_new (SEAT_SIGNAL_SESSION_ADDED,
2002                       G_TYPE_FROM_CLASS (klass),
2003                       G_SIGNAL_RUN_LAST,
2004                       G_STRUCT_OFFSET (SeatClass, session_added),
2005                       NULL, NULL,
2006                       NULL,
2007                       G_TYPE_NONE, 1, SESSION_TYPE);
2008     signals[RUNNING_USER_SESSION] =
2009         g_signal_new (SEAT_SIGNAL_RUNNING_USER_SESSION,
2010                       G_TYPE_FROM_CLASS (klass),
2011                       G_SIGNAL_RUN_LAST,
2012                       G_STRUCT_OFFSET (SeatClass, running_user_session),
2013                       NULL, NULL,
2014                       NULL,
2015                       G_TYPE_NONE, 1, SESSION_TYPE);
2016     signals[SESSION_REMOVED] =
2017         g_signal_new (SEAT_SIGNAL_SESSION_REMOVED,
2018                       G_TYPE_FROM_CLASS (klass),
2019                       G_SIGNAL_RUN_LAST,
2020                       G_STRUCT_OFFSET (SeatClass, session_removed),
2021                       NULL, NULL,
2022                       NULL,
2023                       G_TYPE_NONE, 1, SESSION_TYPE);
2024     signals[STOPPED] =
2025         g_signal_new (SEAT_SIGNAL_STOPPED,
2026                       G_TYPE_FROM_CLASS (klass),
2027                       G_SIGNAL_RUN_LAST,
2028                       G_STRUCT_OFFSET (SeatClass, stopped),
2029                       NULL, NULL,
2030                       NULL,
2031                       G_TYPE_NONE, 0);
2032 }
2033
2034 static gint
2035 seat_real_logprefix (Logger *self, gchar *buf, gulong buflen)
2036 {
2037     return g_snprintf (buf, buflen, "Seat %s: ", SEAT (self)->priv->name);
2038 }
2039
2040 static void
2041 seat_logger_iface_init (LoggerInterface *iface)
2042 {
2043     iface->logprefix = &seat_real_logprefix;
2044 }