src/seat-unity.c

   1 /*
   2  * Copyright (C) 2012-2013 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 <string.h>
  13 #include <fcntl.h>
  14 #include <errno.h>
  15 #include <glib/gstdio.h>
  16
  17 #include "seat-unity.h"
  18 #include "configuration.h"
  19 #include "x-server-local.h"
  20 #include "mir-server.h"
  21 #include "vt.h"
  22 #include "plymouth.h"
  23
  24 typedef enum
  25 {
  26    USC_MESSAGE_PING = 0,
  27    USC_MESSAGE_PONG = 1,
  28    USC_MESSAGE_READY = 2,
  29    USC_MESSAGE_SESSION_CONNECTED = 3,
  30    USC_MESSAGE_SET_ACTIVE_SESSION = 4,
  31    USC_MESSAGE_SET_NEXT_SESSION = 5,
  32 } USCMessageID;
  33
  34 struct SeatUnityPrivate
  35 {
  36     /* VT we are running on */
  37     gint vt;
  38
  39     /* File to log to */
  40     gchar *log_file;
  41
  42     /* Filename of Mir socket */
  43     gchar *mir_socket_filename;
  44
  45     /* Pipes to communicate with compositor */
  46     int to_compositor_pipe[2];
  47     int from_compositor_pipe[2];
  48
  49     /* IO channel listening on for messages from the compositor */
  50     GIOChannel *from_compositor_channel;
  51
  52     /* TRUE when the compositor indicates it is ready */
  53     gboolean compositor_ready;
  54
  55     /* Buffer reading from channel */
  56     guint8 *read_buffer;
  57     gsize read_buffer_length;
  58     gsize read_buffer_n_used;
  59
  60     /* Compositor process */
  61     Process *compositor_process;
  62
  63     /* Timeout when waiting for compositor to start */
  64     guint compositor_timeout;
  65
  66     /* Next Mir ID to use for a compositor client */
  67     gint next_id;
  68
  69     /* TRUE if using VT switching fallback */
  70     gboolean use_vt_switching;
  71
  72     /* The currently visible session */
  73     Session *active_session;
  74     DisplayServer *active_display_server;
  75 };
  76
  77 G_DEFINE_TYPE (SeatUnity, seat_unity, SEAT_TYPE);
  78
  79 static gboolean
  80 seat_unity_get_start_local_sessions (Seat *seat)
  81 {
  82     return !seat_get_string_property (seat, "xdmcp-manager");
  83 }
  84
  85 static void
  86 seat_unity_setup (Seat *seat)
  87 {
  88     seat_set_can_switch (seat, TRUE);
  89     SEAT_CLASS (seat_unity_parent_class)->setup (seat);
  90 }
  91
  92 static void
  93 compositor_stopped_cb (Process *process, SeatUnity *seat)
  94 {
  95     if (seat->priv->compositor_timeout != 0)
  96         g_source_remove (seat->priv->compositor_timeout);
  97     seat->priv->compositor_timeout = 0;
  98
  99     /* Finished with the VT */
 100     vt_unref (seat->priv->vt);
 101     seat->priv->vt = -1;
 102
 103     if (seat_get_is_stopping (SEAT (seat)))
 104     {
 105         SEAT_CLASS (seat_unity_parent_class)->stop (SEAT (seat));
 106         return;
 107     }
 108
 109     /* If stopped before it was ready, then revert to VT mode */
 110     if (!seat->priv->compositor_ready)
 111     {
 112         l_debug (seat, "Compositor failed to start, switching to VT mode");
 113         seat->priv->use_vt_switching = TRUE;
 114         SEAT_CLASS (seat_unity_parent_class)->start (SEAT (seat));
 115         return;
 116     }
 117
 118     l_debug (seat, "Stopping Unity seat, compositor terminated");
 119
 120     seat_stop (SEAT (seat));
 121 }
 122
 123 static void
 124 compositor_run_cb (Process *process, SeatUnity *seat)
 125 {
 126     int fd;
 127
 128     /* Make input non-blocking */
 129     fd = open ("/dev/null", O_RDONLY);
 130     dup2 (fd, STDIN_FILENO);
 131     close (fd);
 132
 133     /* Redirect output to logfile */
 134     if (seat->priv->log_file)
 135     {
 136          int fd;
 137          gchar *old_filename;
 138
 139          /* Move old file out of the way */
 140          old_filename = g_strdup_printf ("%s.old", seat->priv->log_file);
 141          rename (seat->priv->log_file, old_filename);
 142          g_free (old_filename);
 143
 144          /* Create new file and log to it */
 145          fd = g_open (seat->priv->log_file, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 146          if (fd < 0)
 147              l_warning (seat, "Failed to open log file %s: %s", seat->priv->log_file, g_strerror (errno));
 148          else
 149          {
 150              dup2 (fd, STDOUT_FILENO);
 151              dup2 (fd, STDERR_FILENO);
 152              close (fd);
 153          }
 154     }
 155 }
 156
 157 static void
 158 write_message (SeatUnity *seat, guint16 id, const guint8 *payload, guint16 payload_length)
 159 {
 160     guint8 *data;
 161     gsize data_length = 4 + payload_length;
 162
 163     data = g_malloc (data_length);
 164     data[0] = id >> 8;
 165     data[1] = id & 0xFF;
 166     data[2] = payload_length >> 8;
 167     data[3] = payload_length & 0xFF;
 168     memcpy (data + 4, payload, payload_length);
 169
 170     errno = 0;
 171     if (write (seat->priv->to_compositor_pipe[1], data, data_length) != data_length)
 172         l_warning (seat, "Failed to write to compositor: %s", strerror (errno));
 173 }
 174
 175 static gboolean
 176 read_cb (GIOChannel *source, GIOCondition condition, gpointer data)
 177 {
 178     SeatUnity *seat = data;
 179     gsize n_to_read = 0;
 180     guint16 id, payload_length;
 181     /*guint8 *payload;*/
 182
 183     if (condition == G_IO_HUP)
 184     {
 185         l_debug (seat, "Compositor closed communication channel");
 186         return FALSE;
 187     }
 188
 189     /* Work out how much required for a message */
 190     if (seat->priv->read_buffer_n_used < 4)
 191         n_to_read = 4 - seat->priv->read_buffer_n_used;
 192     else
 193     {
 194         payload_length = seat->priv->read_buffer[2] << 8 | seat->priv->read_buffer[3];
 195         n_to_read = 4 + payload_length - seat->priv->read_buffer_n_used;
 196     }
 197
 198     /* Read from compositor */
 199     if (n_to_read > 0)
 200     {
 201         gsize n_total, n_read = 0;
 202         GIOStatus status;
 203         GError *error = NULL;
 204
 205         n_total = seat->priv->read_buffer_n_used + n_to_read;
 206         if (seat->priv->read_buffer_length < n_total)
 207             seat->priv->read_buffer = g_realloc (seat->priv->read_buffer, n_total);
 208
 209         status = g_io_channel_read_chars (source,
 210                                           (gchar *)seat->priv->read_buffer + seat->priv->read_buffer_n_used,
 211                                           n_to_read,
 212                                           &n_read,
 213                                           &error);
 214         if (error)
 215             l_warning (seat, "Failed to read from compositor: %s", error->message);
 216         if (status != G_IO_STATUS_NORMAL)
 217             return TRUE;
 218         g_clear_error (&error);
 219         seat->priv->read_buffer_n_used += n_read;
 220     }
 221
 222     /* Read header */
 223     if (seat->priv->read_buffer_n_used < 4)
 224          return TRUE;
 225     id = seat->priv->read_buffer[0] << 8 | seat->priv->read_buffer[1];
 226     payload_length = seat->priv->read_buffer[2] << 8 | seat->priv->read_buffer[3];
 227
 228     /* Read payload */
 229     if (seat->priv->read_buffer_n_used < 4 + payload_length)
 230         return TRUE;
 231     /*payload = seat->priv->read_buffer + 4;*/
 232
 233     switch (id)
 234     {
 235     case USC_MESSAGE_PING:
 236         l_debug (seat, "PING!");
 237         write_message (seat, USC_MESSAGE_PONG, NULL, 0);
 238         break;
 239     case USC_MESSAGE_PONG:
 240         l_debug (seat, "PONG!");
 241         break;
 242     case USC_MESSAGE_READY:
 243         l_debug (seat, "READY");
 244         if (!seat->priv->compositor_ready)
 245         {
 246             seat->priv->compositor_ready = TRUE;
 247             l_debug (seat, "Compositor ready");
 248             g_source_remove (seat->priv->compositor_timeout);
 249             seat->priv->compositor_timeout = 0;
 250             SEAT_CLASS (seat_unity_parent_class)->start (SEAT (seat));
 251         }
 252         break;
 253     case USC_MESSAGE_SESSION_CONNECTED:
 254         l_debug (seat, "SESSION CONNECTED");
 255         break;
 256     default:
 257         l_warning (seat, "Ignoring unknown message %d with %d octets from system compositor", id, payload_length);
 258         break;
 259     }
 260
 261     /* Clear buffer */
 262     seat->priv->read_buffer_n_used = 0;
 263
 264     return TRUE;
 265 }
 266
 267 static gchar *
 268 get_absolute_command (const gchar *command)
 269 {
 270     gchar **tokens;
 271     gchar *absolute_binary, *absolute_command = NULL;
 272
 273     tokens = g_strsplit (command, " ", 2);
 274
 275     absolute_binary = g_find_program_in_path (tokens[0]);
 276     if (absolute_binary)
 277     {
 278         if (tokens[1])
 279             absolute_command = g_strjoin (" ", absolute_binary, tokens[1], NULL);
 280         else
 281             absolute_command = g_strdup (absolute_binary);
 282         g_free (absolute_binary);
 283     }
 284     else
 285         absolute_command = g_strdup (command);
 286
 287     g_strfreev (tokens);
 288
 289     return absolute_command;
 290 }
 291
 292 static gboolean
 293 compositor_timeout_cb (gpointer data)
 294 {
 295     SeatUnity *seat = data;
 296
 297     /* Stop the compositor - it is not working */
 298     process_stop (seat->priv->compositor_process);
 299
 300     return TRUE;
 301 }
 302
 303 static gboolean
 304 seat_unity_start (Seat *seat)
 305 {
 306     const gchar *compositor_command;
 307     gchar *command, *absolute_command, *dir;
 308     gboolean result;
 309     int timeout;
 310
 311     /* Replace Plymouth if it is running */
 312     if (plymouth_get_is_active () && plymouth_has_active_vt ())
 313     {
 314         gint active_vt = vt_get_active ();
 315         if (active_vt >= vt_get_min ())
 316         {
 317             SEAT_UNITY (seat)->priv->vt = active_vt;
 318             plymouth_quit (TRUE);
 319         }
 320         else
 321             l_debug (seat, "Plymouth is running on VT %d, but this is less than the configured minimum of %d so not replacing it", active_vt, vt_get_min ());
 322     }
 323     if (plymouth_get_is_active ())
 324         plymouth_quit (FALSE);
 325     if (SEAT_UNITY (seat)->priv->vt < 0)
 326         SEAT_UNITY (seat)->priv->vt = vt_get_unused ();
 327     if (SEAT_UNITY (seat)->priv->vt < 0)
 328     {
 329         l_debug (seat, "Failed to get a VT to run on");
 330         return FALSE;
 331     }
 332     vt_ref (SEAT_UNITY (seat)->priv->vt);
 333
 334     /* Create pipes to talk to compositor */
 335     if (pipe (SEAT_UNITY (seat)->priv->to_compositor_pipe) < 0 || pipe (SEAT_UNITY (seat)->priv->from_compositor_pipe) < 0)
 336     {
 337         l_debug (seat, "Failed to create compositor pipes: %s", g_strerror (errno));
 338         return FALSE;
 339     }
 340
 341     /* Don't allow the daemon end of the pipes to be accessed in the compositor */
 342     fcntl (SEAT_UNITY (seat)->priv->to_compositor_pipe[1], F_SETFD, FD_CLOEXEC);
 343     fcntl (SEAT_UNITY (seat)->priv->from_compositor_pipe[0], F_SETFD, FD_CLOEXEC);
 344
 345     /* Listen for messages from the compositor */
 346     SEAT_UNITY (seat)->priv->from_compositor_channel = g_io_channel_unix_new (SEAT_UNITY (seat)->priv->from_compositor_pipe[0]);
 347     g_io_add_watch (SEAT_UNITY (seat)->priv->from_compositor_channel, G_IO_IN | G_IO_HUP, read_cb, seat);
 348
 349     /* Setup logging */
 350     dir = config_get_string (config_get_instance (), "LightDM", "log-directory");
 351     SEAT_UNITY (seat)->priv->log_file = g_build_filename (dir, "unity-system-compositor.log", NULL);
 352     l_debug (seat, "Logging to %s", SEAT_UNITY (seat)->priv->log_file);
 353     g_free (dir);
 354
 355     SEAT_UNITY (seat)->priv->mir_socket_filename = g_strdup ("/tmp/mir_socket"); // FIXME: Use this socket by default as XMir is hardcoded to this
 356     timeout = seat_get_integer_property (seat, "unity-compositor-timeout");
 357     compositor_command = seat_get_string_property (seat, "unity-compositor-command");
 358     command = g_strdup_printf ("%s --from-dm-fd %d --to-dm-fd %d --vt %d", compositor_command, SEAT_UNITY (seat)->priv->to_compositor_pipe[0], SEAT_UNITY (seat)->priv->from_compositor_pipe[1], SEAT_UNITY (seat)->priv->vt);
 359
 360     absolute_command = get_absolute_command (command);
 361     g_free (command);
 362
 363     /* Start the compositor */
 364     process_set_command (SEAT_UNITY (seat)->priv->compositor_process, absolute_command);
 365     g_free (absolute_command);
 366     g_signal_connect (SEAT_UNITY (seat)->priv->compositor_process, "stopped", G_CALLBACK (compositor_stopped_cb), seat);
 367     g_signal_connect (SEAT_UNITY (seat)->priv->compositor_process, "run", G_CALLBACK (compositor_run_cb), seat);
 368     result = process_start (SEAT_UNITY (seat)->priv->compositor_process, FALSE);
 369
 370     /* Close compostor ends of the pipes */
 371     close (SEAT_UNITY (seat)->priv->to_compositor_pipe[0]);
 372     SEAT_UNITY (seat)->priv->to_compositor_pipe[0] = 0;
 373     close (SEAT_UNITY (seat)->priv->from_compositor_pipe[1]);
 374     SEAT_UNITY (seat)->priv->from_compositor_pipe[1] = 0;
 375
 376     if (!result)
 377         return FALSE;
 378
 379     /* Connect to the compositor */
 380     timeout = seat_get_integer_property (seat, "unity-compositor-timeout");
 381     if (timeout <= 0)
 382         timeout = 60;
 383     l_debug (seat, "Waiting for system compositor for %ds", timeout);
 384     SEAT_UNITY (seat)->priv->compositor_timeout = g_timeout_add (timeout * 1000, compositor_timeout_cb, seat);
 385
 386     return TRUE;
 387 }
 388
 389 static DisplayServer *
 390 create_x_server (Seat *seat)
 391 {
 392     XServerLocal *x_server;
 393     const gchar *command = NULL, *layout = NULL, *config_file = NULL, *xdmcp_manager = NULL, *key_name = NULL;
 394     gboolean allow_tcp;
 395     gint port = 0;
 396
 397     l_debug (seat, "Starting X server on Unity compositor");
 398
 399     x_server = x_server_local_new ();
 400
 401     command = seat_get_string_property (seat, "xserver-command");
 402     if (command)
 403         x_server_local_set_command (x_server, command);
 404
 405     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 406         x_server_local_set_vt (x_server, vt_get_unused ());
 407     else
 408     {
 409         gchar *id;
 410
 411         id = g_strdup_printf ("%d", SEAT_UNITY (seat)->priv->next_id);
 412         SEAT_UNITY (seat)->priv->next_id++;
 413         x_server_local_set_mir_id (x_server, id);
 414         x_server_local_set_mir_socket (x_server, SEAT_UNITY (seat)->priv->mir_socket_filename);
 415         g_free (id);
 416     }
 417
 418     layout = seat_get_string_property (seat, "xserver-layout");
 419     if (layout)
 420         x_server_local_set_layout (x_server, layout);
 421
 422     config_file = seat_get_string_property (seat, "xserver-config");
 423     if (config_file)
 424         x_server_local_set_config (x_server, config_file);
 425
 426     allow_tcp = seat_get_boolean_property (seat, "xserver-allow-tcp");
 427     x_server_local_set_allow_tcp (x_server, allow_tcp);
 428
 429     xdmcp_manager = seat_get_string_property (seat, "xdmcp-manager");
 430     if (xdmcp_manager)
 431         x_server_local_set_xdmcp_server (x_server, xdmcp_manager);
 432
 433     port = seat_get_integer_property (seat, "xdmcp-port");
 434     if (port > 0)
 435         x_server_local_set_xdmcp_port (x_server, port);
 436
 437     key_name = seat_get_string_property (seat, "xdmcp-key");
 438     if (key_name)
 439     {
 440         gchar *dir, *path;
 441         GKeyFile *keys;
 442         gboolean result;
 443         GError *error = NULL;
 444
 445         dir = config_get_string (config_get_instance (), "LightDM", "config-directory");
 446         path = g_build_filename (dir, "keys.conf", NULL);
 447         g_free (dir);
 448
 449         keys = g_key_file_new ();
 450         result = g_key_file_load_from_file (keys, path, G_KEY_FILE_NONE, &error);
 451         if (error)
 452             l_debug (seat, "Error getting key %s", error->message);
 453         g_clear_error (&error);
 454
 455         if (result)
 456         {
 457             gchar *key = NULL;
 458
 459             if (g_key_file_has_key (keys, "keyring", key_name, NULL))
 460                 key = g_key_file_get_string (keys, "keyring", key_name, NULL);
 461             else
 462                 l_debug (seat, "Key %s not defined", key_name);
 463
 464             if (key)
 465                 x_server_local_set_xdmcp_key (x_server, key);
 466             g_free (key);
 467         }
 468
 469         g_free (path);
 470         g_key_file_free (keys);
 471     }
 472
 473     return DISPLAY_SERVER (x_server);
 474 }
 475
 476 static DisplayServer *
 477 create_mir_server (Seat *seat)
 478 {
 479     MirServer *mir_server;
 480
 481     mir_server = mir_server_new ();
 482     mir_server_set_parent_socket (mir_server, SEAT_UNITY (seat)->priv->mir_socket_filename);
 483
 484     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 485         mir_server_set_vt (mir_server, vt_get_unused ());
 486     else
 487     {
 488         gchar *id;
 489
 490         id = g_strdup_printf ("%d", SEAT_UNITY (seat)->priv->next_id);
 491         SEAT_UNITY (seat)->priv->next_id++;
 492         mir_server_set_id (mir_server, id);
 493         mir_server_set_parent_socket (mir_server, SEAT_UNITY (seat)->priv->mir_socket_filename);
 494         g_free (id);
 495     }
 496
 497     return DISPLAY_SERVER (mir_server);
 498 }
 499
 500 static DisplayServer *
 501 seat_unity_create_display_server (Seat *seat, const gchar *session_type)
 502 {
 503     if (strcmp (session_type, "x") == 0)
 504         return create_x_server (seat);
 505     else if (strcmp (session_type, "mir") == 0)
 506         return create_mir_server (seat);
 507     else
 508     {
 509         l_warning (seat, "Can't create unsupported display server '%s'", session_type);
 510         return NULL;
 511     }
 512 }
 513
 514 static Greeter *
 515 seat_unity_create_greeter_session (Seat *seat)
 516 {
 517     Greeter *greeter_session;
 518     const gchar *xdg_seat;
 519
 520     greeter_session = SEAT_CLASS (seat_unity_parent_class)->create_greeter_session (seat);
 521     xdg_seat = "seat0";
 522     l_debug (seat, "Setting XDG_SEAT=%s", xdg_seat);
 523     session_set_env (SESSION (greeter_session), "XDG_SEAT", xdg_seat);
 524     if (!SEAT_UNITY (seat)->priv->use_vt_switching)
 525     {
 526         gchar *value = g_strdup_printf ("%d", SEAT_UNITY (seat)->priv->vt);
 527         l_debug (seat, "Setting XDG_VTNR=%s", value);
 528         session_set_env (SESSION (greeter_session), "XDG_VTNR", value);
 529         g_free (value);
 530     }
 531     else
 532         l_debug (seat, "Not setting XDG_VTNR");
 533
 534     return greeter_session;
 535 }
 536
 537 static Session *
 538 seat_unity_create_session (Seat *seat, Session *user_session)
 539 {
 540     Session *session;
 541     const gchar *xdg_seat;
 542
 543     session = SEAT_CLASS (seat_unity_parent_class)->create_session (seat, user_session);
 544     xdg_seat = "seat0";
 545     l_debug (seat, "Setting XDG_SEAT=%s", xdg_seat);
 546     session_set_env (session, "XDG_SEAT", xdg_seat);
 547     if (!SEAT_UNITY (seat)->priv->use_vt_switching)
 548     {
 549         gchar *value = g_strdup_printf ("%d", SEAT_UNITY (seat)->priv->vt);
 550         l_debug (seat, "Setting XDG_VTNR=%s", value);
 551         session_set_env (SESSION (session), "XDG_VTNR", value);
 552         g_free (value);
 553     }
 554     else
 555         l_debug (seat, "Not setting XDG_VTNR");
 556
 557     return session;
 558 }
 559
 560 static void
 561 seat_unity_set_active_session (Seat *seat, Session *session)
 562 {
 563     DisplayServer *display_server;
 564
 565     /* If no compositor, have to use VT switching */
 566     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 567     {
 568         gint vt = display_server_get_vt (session_get_display_server (session));
 569         if (vt >= 0)
 570             vt_set_active (vt);
 571
 572         SEAT_CLASS (seat_unity_parent_class)->set_active_session (seat, session);
 573         return;
 574     }
 575
 576     if (session == SEAT_UNITY (seat)->priv->active_session)
 577         return;
 578     SEAT_UNITY (seat)->priv->active_session = g_object_ref (session);
 579
 580     display_server = session_get_display_server (session);
 581     if (SEAT_UNITY (seat)->priv->active_display_server != display_server)
 582     {
 583         const gchar *id = NULL;
 584
 585         SEAT_UNITY (seat)->priv->active_display_server = g_object_ref (display_server);
 586
 587         if (IS_X_SERVER_LOCAL (display_server))
 588             id = x_server_local_get_mir_id (X_SERVER_LOCAL (display_server));
 589         else if (IS_MIR_SERVER (display_server))
 590             id = mir_server_get_id (MIR_SERVER (display_server));
 591
 592         if (id)
 593         {
 594             l_debug (seat, "Switching to Mir session %s", id);
 595             write_message (SEAT_UNITY (seat), USC_MESSAGE_SET_ACTIVE_SESSION, (const guint8 *) id, strlen (id));
 596         }
 597         else
 598             l_warning (seat, "Failed to work out session ID");
 599     }
 600
 601     SEAT_CLASS (seat_unity_parent_class)->set_active_session (seat, session);
 602 }
 603
 604 static Session *
 605 seat_unity_get_active_session (Seat *seat)
 606 {
 607     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 608     {
 609         gint vt;
 610         GList *link;
 611         vt = vt_get_active ();
 612         if (vt < 0)
 613             return NULL;
 614
 615         for (link = seat_get_sessions (seat); link; link = link->next)
 616         {
 617             Session *session = link->data;
 618             if (display_server_get_vt (session_get_display_server (session)) == vt)
 619                 return session;
 620         }
 621
 622         return NULL;
 623     }
 624
 625     return SEAT_UNITY (seat)->priv->active_session;
 626 }
 627
 628 static void
 629 seat_unity_set_next_session (Seat *seat, Session *session)
 630 {
 631     DisplayServer *display_server;
 632     const gchar *id = NULL;
 633
 634     /* If no compositor, don't worry about it */
 635     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 636         return;
 637
 638     display_server = session_get_display_server (session);
 639     if (IS_MIR_SERVER (display_server))
 640     {
 641         id = mir_server_get_id (MIR_SERVER (display_server));
 642
 643         if (id)
 644         {
 645             g_debug ("Marking Mir session %s as the next session", id);
 646             write_message (SEAT_UNITY (seat), USC_MESSAGE_SET_NEXT_SESSION, (const guint8 *) id, strlen (id));
 647         }
 648         else
 649         {
 650             g_warning ("Failed to work out session ID to mark");
 651         }
 652     }
 653 }
 654
 655 static void
 656 seat_unity_run_script (Seat *seat, DisplayServer *display_server, Process *script)
 657 {
 658     const gchar *path;
 659     XServerLocal *x_server;
 660
 661     x_server = X_SERVER_LOCAL (display_server);
 662     path = x_server_local_get_authority_file_path (x_server);
 663     process_set_env (script, "DISPLAY", x_server_get_address (X_SERVER (x_server)));
 664     process_set_env (script, "XAUTHORITY", path);
 665
 666     SEAT_CLASS (seat_unity_parent_class)->run_script (seat, display_server, script);
 667 }
 668
 669 static void
 670 seat_unity_stop (Seat *seat)
 671 {
 672     /* Stop the compositor first */
 673     if (process_get_is_running (SEAT_UNITY (seat)->priv->compositor_process))
 674     {
 675         process_stop (SEAT_UNITY (seat)->priv->compositor_process);
 676         return;
 677     }
 678
 679     SEAT_CLASS (seat_unity_parent_class)->stop (seat);
 680 }
 681
 682 static void
 683 seat_unity_init (SeatUnity *seat)
 684 {
 685     seat->priv = G_TYPE_INSTANCE_GET_PRIVATE (seat, SEAT_UNITY_TYPE, SeatUnityPrivate);
 686     seat->priv->vt = -1;
 687     seat->priv->compositor_process = process_new ();
 688 }
 689
 690 static void
 691 seat_unity_finalize (GObject *object)
 692 {
 693     SeatUnity *seat = SEAT_UNITY (object);
 694
 695     if (seat->priv->vt >= 0)
 696         vt_unref (seat->priv->vt);
 697     g_free (seat->priv->log_file);
 698     g_free (seat->priv->mir_socket_filename);
 699     close (seat->priv->to_compositor_pipe[0]);
 700     close (seat->priv->to_compositor_pipe[1]);
 701     close (seat->priv->from_compositor_pipe[0]);
 702     close (seat->priv->from_compositor_pipe[1]);
 703     g_io_channel_unref (seat->priv->from_compositor_channel);
 704     g_free (seat->priv->read_buffer);
 705     g_object_unref (seat->priv->compositor_process);
 706     if (seat->priv->active_session)
 707         g_object_unref (seat->priv->active_session);
 708     if (seat->priv->active_display_server)
 709         g_object_unref (seat->priv->active_display_server);
 710
 711     G_OBJECT_CLASS (seat_unity_parent_class)->finalize (object);
 712 }
 713
 714 static void
 715 seat_unity_class_init (SeatUnityClass *klass)
 716 {
 717     GObjectClass *object_class = G_OBJECT_CLASS (klass);
 718     SeatClass *seat_class = SEAT_CLASS (klass);
 719
 720     object_class->finalize = seat_unity_finalize;
 721     seat_class->get_start_local_sessions = seat_unity_get_start_local_sessions;
 722     seat_class->setup = seat_unity_setup;
 723     seat_class->start = seat_unity_start;
 724     seat_class->create_display_server = seat_unity_create_display_server;
 725     seat_class->create_greeter_session = seat_unity_create_greeter_session;
 726     seat_class->create_session = seat_unity_create_session;
 727     seat_class->set_active_session = seat_unity_set_active_session;
 728     seat_class->get_active_session = seat_unity_get_active_session;
 729     seat_class->set_next_session = seat_unity_set_next_session;
 730     seat_class->run_script = seat_unity_run_script;
 731     seat_class->stop = seat_unity_stop;
 732
 733     g_type_class_add_private (klass, sizeof (SeatUnityPrivate));
 734 }