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