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