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     /* TRUE if using VT switching fallback */
  73     gboolean use_vt_switching;
  74
  75     /* The currently visible session */
  76     Session *active_session;
  77     DisplayServer *active_display_server;
  78 };
  79
  80 G_DEFINE_TYPE (SeatUnity, seat_unity, SEAT_TYPE);
  81
  82 static gboolean
  83 seat_unity_get_start_local_sessions (Seat *seat)
  84 {
  85     return !seat_get_string_property (seat, "xdmcp-manager");
  86 }
  87
  88 static void
  89 seat_unity_setup (Seat *seat)
  90 {
  91     seat_set_can_switch (seat, TRUE);
  92     SEAT_CLASS (seat_unity_parent_class)->setup (seat);
  93 }
  94
  95 static void
  96 compositor_stopped_cb (Process *process, SeatUnity *seat)
  97 {
  98     if (seat->priv->compositor_timeout != 0)
  99         g_source_remove (seat->priv->compositor_timeout);
 100     seat->priv->compositor_timeout = 0;
 101
 102     /* Finished with the VT */
 103     vt_unref (seat->priv->vt);
 104     seat->priv->vt = -1;
 105
 106     if (seat_get_is_stopping (SEAT (seat)))
 107     {
 108         SEAT_CLASS (seat_unity_parent_class)->stop (SEAT (seat));
 109         return;
 110     }
 111
 112     /* If stopped before it was ready, then revert to VT mode */
 113     if (!seat->priv->compositor_ready)
 114     {
 115         l_debug (seat, "Compositor failed to start, switching to VT mode");
 116         seat->priv->use_vt_switching = TRUE;
 117         SEAT_CLASS (seat_unity_parent_class)->start (SEAT (seat));
 118         return;
 119     }
 120
 121     l_debug (seat, "Stopping Unity seat, compositor terminated");
 122
 123     seat_stop (SEAT (seat));
 124 }
 125
 126 static void
 127 compositor_run_cb (Process *process, SeatUnity *seat)
 128 {
 129     int fd;
 130
 131     /* Make input non-blocking */
 132     fd = open ("/dev/null", O_RDONLY);
 133     dup2 (fd, STDIN_FILENO);
 134     close (fd);
 135
 136     /* Redirect output to logfile */
 137     if (seat->priv->log_file)
 138     {
 139          int fd;
 140          gchar *old_filename;
 141
 142          /* Move old file out of the way */
 143          old_filename = g_strdup_printf ("%s.old", seat->priv->log_file);
 144          rename (seat->priv->log_file, old_filename);
 145          g_free (old_filename);
 146
 147          /* Create new file and log to it */
 148          fd = g_open (seat->priv->log_file, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 149          if (fd < 0)
 150              l_warning (seat, "Failed to open log file %s: %s", seat->priv->log_file, g_strerror (errno));
 151          else
 152          {
 153              dup2 (fd, STDOUT_FILENO);
 154              dup2 (fd, STDERR_FILENO);
 155              close (fd);
 156          }
 157     }
 158 }
 159
 160 static void
 161 write_message (SeatUnity *seat, guint16 id, const guint8 *payload, guint16 payload_length)
 162 {
 163     guint8 *data;
 164     gsize data_length = 4 + payload_length;
 165
 166     data = g_malloc (data_length);
 167     data[0] = id >> 8;
 168     data[1] = id & 0xFF;
 169     data[2] = payload_length >> 8;
 170     data[3] = payload_length & 0xFF;
 171     memcpy (data + 4, payload, payload_length);
 172
 173     errno = 0;
 174     if (write (seat->priv->to_compositor_pipe[1], data, data_length) != data_length)
 175         l_warning (seat, "Failed to write to compositor: %s", strerror (errno));
 176 }
 177
 178 static gboolean
 179 read_cb (GIOChannel *source, GIOCondition condition, gpointer data)
 180 {
 181     SeatUnity *seat = data;
 182     gsize n_to_read = 0;
 183     guint16 id, payload_length;
 184     /*guint8 *payload;*/
 185
 186     if (condition == G_IO_HUP)
 187     {
 188         l_debug (seat, "Compositor closed communication channel");
 189         return FALSE;
 190     }
 191
 192     /* Work out how much required for a message */
 193     if (seat->priv->read_buffer_n_used < 4)
 194         n_to_read = 4 - seat->priv->read_buffer_n_used;
 195     else
 196     {
 197         payload_length = seat->priv->read_buffer[2] << 8 | seat->priv->read_buffer[3];
 198         n_to_read = 4 + payload_length - seat->priv->read_buffer_n_used;
 199     }
 200
 201     /* Read from compositor */
 202     if (n_to_read > 0)
 203     {
 204         gsize n_total, n_read = 0;
 205         GIOStatus status;
 206         GError *error = NULL;
 207
 208         n_total = seat->priv->read_buffer_n_used + n_to_read;
 209         if (seat->priv->read_buffer_length < n_total)
 210             seat->priv->read_buffer = g_realloc (seat->priv->read_buffer, n_total);
 211
 212         status = g_io_channel_read_chars (source,
 213                                           (gchar *)seat->priv->read_buffer + seat->priv->read_buffer_n_used,
 214                                           n_to_read,
 215                                           &n_read,
 216                                           &error);
 217         if (error)
 218             l_warning (seat, "Failed to read from compositor: %s", error->message);
 219         if (status != G_IO_STATUS_NORMAL)
 220             return TRUE;
 221         g_clear_error (&error);
 222         seat->priv->read_buffer_n_used += n_read;
 223     }
 224
 225     /* Read header */
 226     if (seat->priv->read_buffer_n_used < 4)
 227          return TRUE;
 228     id = seat->priv->read_buffer[0] << 8 | seat->priv->read_buffer[1];
 229     payload_length = seat->priv->read_buffer[2] << 8 | seat->priv->read_buffer[3];
 230
 231     /* Read payload */
 232     if (seat->priv->read_buffer_n_used < 4 + payload_length)
 233         return TRUE;
 234     /*payload = seat->priv->read_buffer + 4;*/
 235
 236     switch (id)
 237     {
 238     case USC_MESSAGE_PING:
 239         l_debug (seat, "PING!");
 240         write_message (seat, USC_MESSAGE_PONG, NULL, 0);
 241         break;
 242     case USC_MESSAGE_PONG:
 243         l_debug (seat, "PONG!");
 244         break;
 245     case USC_MESSAGE_READY:
 246         l_debug (seat, "READY");
 247         if (!seat->priv->compositor_ready)
 248         {
 249             seat->priv->compositor_ready = TRUE;
 250             l_debug (seat, "Compositor ready");
 251             g_source_remove (seat->priv->compositor_timeout);
 252             seat->priv->compositor_timeout = 0;
 253             SEAT_CLASS (seat_unity_parent_class)->start (SEAT (seat));
 254         }
 255         break;
 256     case USC_MESSAGE_SESSION_CONNECTED:
 257         l_debug (seat, "SESSION CONNECTED");
 258         break;
 259     default:
 260         l_warning (seat, "Ignoring unknown message %d with %d octets from system compositor", id, payload_length);
 261         break;
 262     }
 263
 264     /* Clear buffer */
 265     seat->priv->read_buffer_n_used = 0;
 266
 267     return TRUE;
 268 }
 269
 270 static gchar *
 271 get_absolute_command (const gchar *command)
 272 {
 273     gchar **tokens;
 274     gchar *absolute_binary, *absolute_command = NULL;
 275
 276     tokens = g_strsplit (command, " ", 2);
 277
 278     absolute_binary = g_find_program_in_path (tokens[0]);
 279     if (absolute_binary)
 280     {
 281         if (tokens[1])
 282             absolute_command = g_strjoin (" ", absolute_binary, tokens[1], NULL);
 283         else
 284             absolute_command = g_strdup (absolute_binary);
 285         g_free (absolute_binary);
 286     }
 287     else
 288         absolute_command = g_strdup (command);
 289
 290     g_strfreev (tokens);
 291
 292     return absolute_command;
 293 }
 294
 295 static gboolean
 296 compositor_timeout_cb (gpointer data)
 297 {
 298     SeatUnity *seat = data;
 299
 300     /* Stop the compositor - it is not working */
 301     process_stop (seat->priv->compositor_process);
 302
 303     return TRUE;
 304 }
 305
 306 static gboolean
 307 seat_unity_start (Seat *seat)
 308 {
 309     const gchar *compositor_command;
 310     gchar *command, *absolute_command, *dir, *value;
 311     gboolean result;
 312     int timeout;
 313
 314     /* Replace Plymouth if it is running */
 315     if (plymouth_get_is_active () && plymouth_has_active_vt ())
 316     {
 317         gint active_vt = vt_get_active ();
 318         if (active_vt >= vt_get_min ())
 319         {
 320             SEAT_UNITY (seat)->priv->vt = active_vt;
 321             plymouth_quit (TRUE);
 322         }
 323         else
 324             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 ());
 325     }
 326     if (plymouth_get_is_active ())
 327         plymouth_quit (FALSE);
 328     if (SEAT_UNITY (seat)->priv->vt < 0)
 329         SEAT_UNITY (seat)->priv->vt = vt_get_unused ();
 330     if (SEAT_UNITY (seat)->priv->vt < 0)
 331     {
 332         l_debug (seat, "Failed to get a VT to run on");
 333         return FALSE;
 334     }
 335     vt_ref (SEAT_UNITY (seat)->priv->vt);
 336
 337     /* Create pipes to talk to compositor */
 338     if (pipe (SEAT_UNITY (seat)->priv->to_compositor_pipe) < 0 || pipe (SEAT_UNITY (seat)->priv->from_compositor_pipe) < 0)
 339     {
 340         l_debug (seat, "Failed to create compositor pipes: %s", g_strerror (errno));
 341         return FALSE;
 342     }
 343
 344     /* Don't allow the daemon end of the pipes to be accessed in the compositor */
 345     fcntl (SEAT_UNITY (seat)->priv->to_compositor_pipe[1], F_SETFD, FD_CLOEXEC);
 346     fcntl (SEAT_UNITY (seat)->priv->from_compositor_pipe[0], F_SETFD, FD_CLOEXEC);
 347
 348     /* Listen for messages from the compositor */
 349     SEAT_UNITY (seat)->priv->from_compositor_channel = g_io_channel_unix_new (SEAT_UNITY (seat)->priv->from_compositor_pipe[0]);
 350     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);
 351
 352     /* Setup logging */
 353     dir = config_get_string (config_get_instance (), "LightDM", "log-directory");
 354     SEAT_UNITY (seat)->priv->log_file = g_build_filename (dir, "unity-system-compositor.log", NULL);
 355     l_debug (seat, "Logging to %s", SEAT_UNITY (seat)->priv->log_file);
 356     g_free (dir);
 357
 358     /* Setup environment */
 359     process_set_clear_environment (SEAT_UNITY (seat)->priv->compositor_process, TRUE);
 360     process_set_env (SEAT_UNITY (seat)->priv->compositor_process, "XDG_SEAT", "seat0");
 361     value = g_strdup_printf ("%d", SEAT_UNITY (seat)->priv->vt);
 362     process_set_env (SEAT_UNITY (seat)->priv->compositor_process, "XDG_VTNR", value);
 363     g_free (value);
 364     /* Variable required for regression tests */
 365     if (g_getenv ("LIGHTDM_TEST_ROOT"))
 366     {
 367         process_set_env (SEAT_UNITY (seat)->priv->compositor_process, "LIGHTDM_TEST_ROOT", g_getenv ("LIGHTDM_TEST_ROOT"));
 368         process_set_env (SEAT_UNITY (seat)->priv->compositor_process, "LD_PRELOAD", g_getenv ("LD_PRELOAD"));
 369         process_set_env (SEAT_UNITY (seat)->priv->compositor_process, "LD_LIBRARY_PATH", g_getenv ("LD_LIBRARY_PATH"));
 370     }
 371
 372     SEAT_UNITY (seat)->priv->mir_socket_filename = g_strdup ("/tmp/mir_socket"); // FIXME: Use this socket by default as XMir is hardcoded to this
 373     timeout = seat_get_integer_property (seat, "unity-compositor-timeout");
 374     compositor_command = seat_get_string_property (seat, "unity-compositor-command");
 375     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);
 376
 377     absolute_command = get_absolute_command (command);
 378     g_free (command);
 379
 380     /* Start the compositor */
 381     process_set_command (SEAT_UNITY (seat)->priv->compositor_process, absolute_command);
 382     g_free (absolute_command);
 383     g_signal_connect (SEAT_UNITY (seat)->priv->compositor_process, "stopped", G_CALLBACK (compositor_stopped_cb), seat);
 384     g_signal_connect (SEAT_UNITY (seat)->priv->compositor_process, "run", G_CALLBACK (compositor_run_cb), seat);
 385     result = process_start (SEAT_UNITY (seat)->priv->compositor_process, FALSE);
 386
 387     /* Close compostor ends of the pipes */
 388     close (SEAT_UNITY (seat)->priv->to_compositor_pipe[0]);
 389     SEAT_UNITY (seat)->priv->to_compositor_pipe[0] = 0;
 390     close (SEAT_UNITY (seat)->priv->from_compositor_pipe[1]);
 391     SEAT_UNITY (seat)->priv->from_compositor_pipe[1] = 0;
 392
 393     if (!result)
 394         return FALSE;
 395
 396     /* Connect to the compositor */
 397     timeout = seat_get_integer_property (seat, "unity-compositor-timeout");
 398     if (timeout <= 0)
 399         timeout = 60;
 400     l_debug (seat, "Waiting for system compositor for %ds", timeout);
 401     SEAT_UNITY (seat)->priv->compositor_timeout = g_timeout_add (timeout * 1000, compositor_timeout_cb, seat);
 402
 403     return TRUE;
 404 }
 405
 406 static DisplayServer *
 407 create_x_server (Seat *seat)
 408 {
 409     XServerLocal *x_server;
 410     const gchar *command = NULL, *layout = NULL, *config_file = NULL, *xdmcp_manager = NULL, *key_name = NULL, *xdg_seat = NULL;
 411     gboolean allow_tcp;
 412     gint port = 0;
 413
 414     l_debug (seat, "Starting X server on Unity compositor");
 415
 416     x_server = x_server_local_new ();
 417
 418     command = seat_get_string_property (seat, "xserver-command");
 419     if (command)
 420         x_server_local_set_command (x_server, command);
 421
 422     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 423         x_server_local_set_vt (x_server, vt_get_unused ());
 424     else
 425     {
 426         gchar *id;
 427
 428         id = g_strdup_printf ("x-%d", SEAT_UNITY (seat)->priv->next_x_server_id);
 429         SEAT_UNITY (seat)->priv->next_x_server_id++;
 430         x_server_local_set_mir_id (x_server, id);
 431         x_server_local_set_mir_socket (x_server, SEAT_UNITY (seat)->priv->mir_socket_filename);
 432         g_free (id);
 433     }
 434
 435     layout = seat_get_string_property (seat, "xserver-layout");
 436     if (layout)
 437         x_server_local_set_layout (x_server, layout);
 438
 439     xdg_seat = seat_get_string_property (seat, "xdg-seat");
 440     if (xdg_seat)
 441         x_server_local_set_xdg_seat (x_server, xdg_seat);
 442
 443     config_file = seat_get_string_property (seat, "xserver-config");
 444     if (config_file)
 445         x_server_local_set_config (x_server, config_file);
 446
 447     allow_tcp = seat_get_boolean_property (seat, "xserver-allow-tcp");
 448     x_server_local_set_allow_tcp (x_server, allow_tcp);
 449
 450     xdmcp_manager = seat_get_string_property (seat, "xdmcp-manager");
 451     if (xdmcp_manager)
 452         x_server_local_set_xdmcp_server (x_server, xdmcp_manager);
 453
 454     port = seat_get_integer_property (seat, "xdmcp-port");
 455     if (port > 0)
 456         x_server_local_set_xdmcp_port (x_server, port);
 457
 458     key_name = seat_get_string_property (seat, "xdmcp-key");
 459     if (key_name)
 460     {
 461         gchar *dir, *path;
 462         GKeyFile *keys;
 463         gboolean result;
 464         GError *error = NULL;
 465
 466         dir = config_get_string (config_get_instance (), "LightDM", "config-directory");
 467         path = g_build_filename (dir, "keys.conf", NULL);
 468         g_free (dir);
 469
 470         keys = g_key_file_new ();
 471         result = g_key_file_load_from_file (keys, path, G_KEY_FILE_NONE, &error);
 472         if (error)
 473             l_debug (seat, "Error getting key %s", error->message);
 474         g_clear_error (&error);
 475
 476         if (result)
 477         {
 478             gchar *key = NULL;
 479
 480             if (g_key_file_has_key (keys, "keyring", key_name, NULL))
 481                 key = g_key_file_get_string (keys, "keyring", key_name, NULL);
 482             else
 483                 l_debug (seat, "Key %s not defined", key_name);
 484
 485             if (key)
 486                 x_server_local_set_xdmcp_key (x_server, key);
 487             g_free (key);
 488         }
 489
 490         g_free (path);
 491         g_key_file_free (keys);
 492     }
 493
 494     return DISPLAY_SERVER (x_server);
 495 }
 496
 497 static DisplayServer *
 498 create_mir_server (Seat *seat)
 499 {
 500     MirServer *mir_server;
 501
 502     mir_server = mir_server_new ();
 503     mir_server_set_parent_socket (mir_server, SEAT_UNITY (seat)->priv->mir_socket_filename);
 504
 505     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 506         mir_server_set_vt (mir_server, vt_get_unused ());
 507
 508     return DISPLAY_SERVER (mir_server);
 509 }
 510
 511 static DisplayServer *
 512 seat_unity_create_display_server (Seat *seat, const gchar *session_type)
 513 {
 514     if (strcmp (session_type, "x") == 0)
 515         return create_x_server (seat);
 516     else if (strcmp (session_type, "mir") == 0)
 517         return create_mir_server (seat);
 518     else
 519     {
 520         l_warning (seat, "Can't create unsupported display server '%s'", session_type);
 521         return NULL;
 522     }
 523 }
 524
 525 static Greeter *
 526 seat_unity_create_greeter_session (Seat *seat)
 527 {
 528     Greeter *greeter_session;
 529     const gchar *xdg_seat;
 530     gchar *id;
 531     gint vt = -1;
 532
 533     greeter_session = SEAT_CLASS (seat_unity_parent_class)->create_greeter_session (seat);
 534     xdg_seat = seat_get_string_property (seat, "xdg-seat");
 535     if (!xdg_seat)
 536         xdg_seat = "seat0";
 537     l_debug (seat, "Setting XDG_SEAT=%s", xdg_seat);
 538     session_set_env (SESSION (greeter_session), "XDG_SEAT", xdg_seat);
 539
 540     id = g_strdup_printf ("greeter-%d", SEAT_UNITY (seat)->priv->next_greeter_id);
 541     SEAT_UNITY (seat)->priv->next_greeter_id++;
 542     session_set_env (SESSION (greeter_session), "MIR_SERVER_NAME", id);
 543     g_free (id);
 544
 545     if (!SEAT_UNITY (seat)->priv->use_vt_switching)
 546         vt = SEAT_UNITY (seat)->priv->vt;
 547
 548     if (vt >= 0)
 549     {
 550         gchar *value = g_strdup_printf ("%d", vt);
 551         l_debug (seat, "Setting XDG_VTNR=%s", value);
 552         session_set_env (SESSION (greeter_session), "XDG_VTNR", value);
 553         g_free (value);
 554     }
 555     else
 556         l_debug (seat, "Not setting XDG_VTNR");
 557
 558     return greeter_session;
 559 }
 560
 561 static Session *
 562 seat_unity_create_session (Seat *seat)
 563 {
 564     Session *session;
 565     const gchar *xdg_seat;
 566     gchar *id;
 567     gint vt = -1;
 568
 569     session = SEAT_CLASS (seat_unity_parent_class)->create_session (seat);
 570     xdg_seat = seat_get_string_property (seat, "xdg-seat");
 571     if (!xdg_seat)
 572         xdg_seat = "seat0";
 573     l_debug (seat, "Setting XDG_SEAT=%s", xdg_seat);
 574     session_set_env (session, "XDG_SEAT", xdg_seat);
 575
 576     id = g_strdup_printf ("session-%d", SEAT_UNITY (seat)->priv->next_session_id);
 577     SEAT_UNITY (seat)->priv->next_session_id++;
 578     session_set_env (session, "MIR_SERVER_NAME", id);
 579     g_free (id);
 580
 581     if (!SEAT_UNITY (seat)->priv->use_vt_switching)
 582         vt = SEAT_UNITY (seat)->priv->vt;
 583
 584     if (vt >= 0)
 585     {
 586         gchar *value = g_strdup_printf ("%d", vt);
 587         l_debug (seat, "Setting XDG_VTNR=%s", value);
 588         session_set_env (SESSION (session), "XDG_VTNR", value);
 589         g_free (value);
 590     }
 591     else
 592         l_debug (seat, "Not setting XDG_VTNR");
 593
 594     return session;
 595 }
 596
 597 static void
 598 seat_unity_set_active_session (Seat *seat, Session *session)
 599 {
 600     DisplayServer *display_server;
 601
 602     /* If no compositor, have to use VT switching */
 603     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 604     {
 605         gint vt = display_server_get_vt (session_get_display_server (session));
 606         if (vt >= 0)
 607             vt_set_active (vt);
 608
 609         SEAT_CLASS (seat_unity_parent_class)->set_active_session (seat, session);
 610         return;
 611     }
 612
 613     if (session == SEAT_UNITY (seat)->priv->active_session)
 614         return;
 615     SEAT_UNITY (seat)->priv->active_session = g_object_ref (session);
 616
 617     display_server = session_get_display_server (session);
 618     if (SEAT_UNITY (seat)->priv->active_display_server != display_server)
 619     {
 620         const gchar *id = NULL;
 621
 622         SEAT_UNITY (seat)->priv->active_display_server = g_object_ref (display_server);
 623
 624         if (IS_X_SERVER_LOCAL (display_server))
 625             id = x_server_local_get_mir_id (X_SERVER_LOCAL (display_server));
 626         else
 627             id = session_get_env (session, "MIR_SERVER_NAME");
 628
 629         if (id)
 630         {
 631             l_debug (seat, "Switching to Mir session %s", id);
 632             write_message (SEAT_UNITY (seat), USC_MESSAGE_SET_ACTIVE_SESSION, (const guint8 *) id, strlen (id));
 633         }
 634         else
 635             l_warning (seat, "Failed to work out session ID");
 636     }
 637
 638     SEAT_CLASS (seat_unity_parent_class)->set_active_session (seat, session);
 639 }
 640
 641 static Session *
 642 seat_unity_get_active_session (Seat *seat)
 643 {
 644     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 645     {
 646         gint vt;
 647         GList *link;
 648         vt = vt_get_active ();
 649         if (vt < 0)
 650             return NULL;
 651
 652         for (link = seat_get_sessions (seat); link; link = link->next)
 653         {
 654             Session *session = link->data;
 655             if (display_server_get_vt (session_get_display_server (session)) == vt)
 656                 return session;
 657         }
 658
 659         return NULL;
 660     }
 661
 662     return SEAT_UNITY (seat)->priv->active_session;
 663 }
 664
 665 static void
 666 seat_unity_set_next_session (Seat *seat, Session *session)
 667 {
 668     DisplayServer *display_server;
 669     const gchar *id = NULL;
 670
 671     if (!session)
 672         return;
 673
 674     /* If no compositor, don't worry about it */
 675     if (SEAT_UNITY (seat)->priv->use_vt_switching)
 676         return;
 677
 678     display_server = session_get_display_server (session);
 679
 680     if (IS_X_SERVER_LOCAL (display_server))
 681         id = x_server_local_get_mir_id (X_SERVER_LOCAL (display_server));
 682     else
 683         id = session_get_env (session, "MIR_SESSION_NAME");
 684
 685     if (id)
 686     {
 687         l_debug (seat, "Marking Mir session %s as the next session", id);
 688         write_message (SEAT_UNITY (seat), USC_MESSAGE_SET_NEXT_SESSION, (const guint8 *) id, strlen (id));
 689     }
 690     else
 691     {
 692         l_debug (seat, "Failed to work out session ID to mark");
 693     }
 694
 695     SEAT_CLASS (seat_unity_parent_class)->set_next_session (seat, session);
 696 }
 697
 698 static void
 699 seat_unity_run_script (Seat *seat, DisplayServer *display_server, Process *script)
 700 {
 701     const gchar *path;
 702     XServerLocal *x_server;
 703
 704     x_server = X_SERVER_LOCAL (display_server);
 705     path = x_server_local_get_authority_file_path (x_server);
 706     process_set_env (script, "DISPLAY", x_server_get_address (X_SERVER (x_server)));
 707     process_set_env (script, "XAUTHORITY", path);
 708
 709     SEAT_CLASS (seat_unity_parent_class)->run_script (seat, display_server, script);
 710 }
 711
 712 static void
 713 seat_unity_stop (Seat *seat)
 714 {
 715     /* Stop the compositor first */
 716     if (process_get_is_running (SEAT_UNITY (seat)->priv->compositor_process))
 717     {
 718         process_stop (SEAT_UNITY (seat)->priv->compositor_process);
 719         return;
 720     }
 721
 722     SEAT_CLASS (seat_unity_parent_class)->stop (seat);
 723 }
 724
 725 static void
 726 seat_unity_init (SeatUnity *seat)
 727 {
 728     seat->priv = G_TYPE_INSTANCE_GET_PRIVATE (seat, SEAT_UNITY_TYPE, SeatUnityPrivate);
 729     seat->priv->vt = -1;
 730     seat->priv->compositor_process = process_new ();
 731 }
 732
 733 static void
 734 seat_unity_finalize (GObject *object)
 735 {
 736     SeatUnity *seat = SEAT_UNITY (object);
 737
 738     if (seat->priv->vt >= 0)
 739         vt_unref (seat->priv->vt);
 740     g_free (seat->priv->log_file);
 741     g_free (seat->priv->mir_socket_filename);
 742     close (seat->priv->to_compositor_pipe[0]);
 743     close (seat->priv->to_compositor_pipe[1]);
 744     close (seat->priv->from_compositor_pipe[0]);
 745     close (seat->priv->from_compositor_pipe[1]);
 746     g_io_channel_unref (seat->priv->from_compositor_channel);
 747     g_source_remove (seat->priv->from_compositor_watch);
 748     g_free (seat->priv->read_buffer);
 749     g_object_unref (seat->priv->compositor_process);
 750     if (seat->priv->active_session)
 751         g_object_unref (seat->priv->active_session);
 752     if (seat->priv->active_display_server)
 753         g_object_unref (seat->priv->active_display_server);
 754
 755     G_OBJECT_CLASS (seat_unity_parent_class)->finalize (object);
 756 }
 757
 758 static void
 759 seat_unity_class_init (SeatUnityClass *klass)
 760 {
 761     GObjectClass *object_class = G_OBJECT_CLASS (klass);
 762     SeatClass *seat_class = SEAT_CLASS (klass);
 763
 764     object_class->finalize = seat_unity_finalize;
 765     seat_class->get_start_local_sessions = seat_unity_get_start_local_sessions;
 766     seat_class->setup = seat_unity_setup;
 767     seat_class->start = seat_unity_start;
 768     seat_class->create_display_server = seat_unity_create_display_server;
 769     seat_class->create_greeter_session = seat_unity_create_greeter_session;
 770     seat_class->create_session = seat_unity_create_session;
 771     seat_class->set_active_session = seat_unity_set_active_session;
 772     seat_class->get_active_session = seat_unity_get_active_session;
 773     seat_class->set_next_session = seat_unity_set_next_session;
 774     seat_class->run_script = seat_unity_run_script;
 775     seat_class->stop = seat_unity_stop;
 776
 777     g_type_class_add_private (klass, sizeof (SeatUnityPrivate));
 778 }