/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- * * Copyright (C) 2007 William Jon McCann * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gdm-manager.h" #include "gdm-log.h" #include "gdm-common.h" #include "gdm-settings.h" #include "gdm-settings-direct.h" #include "gdm-settings-keys.h" #define GDM_DBUS_NAME "org.gnome.DisplayManager" static GDBusConnection *get_system_bus (void); static gboolean bus_reconnect (void); extern char **environ; static GdmManager *manager = NULL; static int name_id = -1; static GdmSettings *settings = NULL; static uid_t gdm_uid = -1; static gid_t gdm_gid = -1; static gboolean timed_exit_cb (GMainLoop *loop) { g_main_loop_quit (loop); return FALSE; } static void bus_connection_closed (void) { g_debug ("Disconnected from D-Bus"); if (manager == NULL) { /* probably shutting down or something */ return; } g_clear_object (&manager); g_timeout_add_seconds (3, (GSourceFunc)bus_reconnect, NULL); } static GDBusConnection * get_system_bus (void) { GError *error; GDBusConnection *bus; error = NULL; bus = g_bus_get_sync (G_BUS_TYPE_SYSTEM, NULL, &error); if (bus == NULL) { g_warning ("Couldn't connect to system bus: %s", error->message); g_error_free (error); goto out; } g_signal_connect (bus, "closed", G_CALLBACK (bus_connection_closed), NULL); g_dbus_connection_set_exit_on_close (bus, FALSE); out: return bus; } static void delete_pid (void) { g_unlink (GDM_PID_FILE); } static void write_pid (void) { int pf; ssize_t written; char pid[9]; errno = 0; pf = open (GDM_PID_FILE, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, 0644); if (pf < 0) { g_warning (_("Cannot write PID file %s: possibly out of disk space: %s"), GDM_PID_FILE, g_strerror (errno)); return; } snprintf (pid, sizeof (pid), "%lu\n", (long unsigned) getpid ()); errno = 0; written = write (pf, pid, strlen (pid)); close (pf); if (written < 0) { g_warning (_("Cannot write PID file %s: possibly out of disk space: %s"), GDM_PID_FILE, g_strerror (errno)); return; } atexit (delete_pid); } static void delete_first_run_marker (void) { g_unlink (GDM_RAN_ONCE_MARKER_FILE); } static gboolean ensure_dir_with_perms (const char *path, uid_t uid, gid_t gid, mode_t mode, GError **error) { gboolean ret = FALSE; if (g_mkdir_with_parents (path, 0755) == -1) { g_set_error_literal (error, G_IO_ERROR, g_io_error_from_errno (errno), g_strerror (errno)); goto out; } if (g_chmod (path, mode) == -1) { g_set_error_literal (error, G_IO_ERROR, g_io_error_from_errno (errno), g_strerror (errno)); goto out; } if (chown (path, uid, gid) == -1) { g_set_error_literal (error, G_IO_ERROR, g_io_error_from_errno (errno), g_strerror (errno)); goto out; } ret = TRUE; out: return ret; } static void gdm_daemon_ensure_dirs (uid_t uid, gid_t gid) { GError *error = NULL; /* Set up /var/run/gdm */ if (!ensure_dir_with_perms (GDM_RAN_ONCE_MARKER_DIR, 0, gid, (S_IRWXU | S_IRWXG), &error)) { gdm_fail (_("Failed to create ran once marker dir %s: %s"), GDM_RAN_ONCE_MARKER_DIR, error->message); } /* Set up /var/gdm */ if (!ensure_dir_with_perms (AUTHDIR, uid, gid, (S_IRWXU | S_IRWXG | S_ISVTX), &error)) { gdm_fail (_("Failed to create AuthDir %s: %s"), AUTHDIR, error->message); } /* Set up /var/log/gdm */ if (!ensure_dir_with_perms (LOGDIR, 0, gid, (S_IRWXU | S_IRWXG | S_ISVTX), &error)) { gdm_fail (_("Failed to create LogDir %s: %s"), LOGDIR, error->message); } } static void gdm_daemon_lookup_user (uid_t *uidp, gid_t *gidp) { char *username; char *groupname; uid_t uid; gid_t gid; struct passwd *pwent; struct group *grent; username = NULL; groupname = NULL; uid = 0; gid = 0; gdm_settings_direct_get_string (GDM_KEY_USER, &username); gdm_settings_direct_get_string (GDM_KEY_GROUP, &groupname); if (username == NULL || groupname == NULL) { return; } g_debug ("Changing user:group to %s:%s", username, groupname); /* Lookup user and groupid for the GDM user */ gdm_get_pwent_for_name (username, &pwent); /* Set uid and gid */ if G_UNLIKELY (pwent == NULL) { gdm_fail (_("Can't find the GDM user '%s'. Aborting!"), username); } else { uid = pwent->pw_uid; } if G_UNLIKELY (uid == 0) { gdm_fail (_("The GDM user should not be root. Aborting!")); } grent = getgrnam (groupname); if G_UNLIKELY (grent == NULL) { gdm_fail (_("Can't find the GDM group '%s'. Aborting!"), groupname); } else { gid = grent->gr_gid; } if G_UNLIKELY (gid == 0) { gdm_fail (_("The GDM group should not be root. Aborting!")); } if (uidp != NULL) { *uidp = uid; } if (gidp != NULL) { *gidp = gid; } g_free (username); g_free (groupname); } static gboolean on_shutdown_signal_cb (gpointer user_data) { GMainLoop *mainloop = user_data; g_main_loop_quit (mainloop); return FALSE; } static gboolean on_sighup_cb (gpointer user_data) { g_debug ("Got HUP signal"); /* Reread config stuff like system config files, VPN service * files, etc */ g_object_unref (settings); settings = gdm_settings_new (); if (settings != NULL) { if (! gdm_settings_direct_init (settings, DATADIR "/gdm/gdm.schemas", "/")) { g_warning ("Unable to initialize settings"); } } return TRUE; } static gboolean on_sigusr1_cb (gpointer user_data) { g_debug ("Got USR1 signal"); gdm_log_toggle_debug (); return TRUE; } static gboolean is_debug_set (void) { gboolean debug = FALSE; /* enable debugging for unstable builds */ if (gdm_is_version_unstable ()) { return TRUE; } gdm_settings_direct_get_boolean (GDM_KEY_DEBUG, &debug); return debug; } int main (int argc, char **argv) { GMainLoop *main_loop; GOptionContext *context; GError *error = NULL; int ret; gboolean res; static gboolean do_timed_exit = FALSE; static gboolean print_version = FALSE; static gboolean fatal_warnings = FALSE; static GOptionEntry entries [] = { { "fatal-warnings", 0, 0, G_OPTION_ARG_NONE, &fatal_warnings, N_("Make all warnings fatal"), NULL }, { "timed-exit", 0, 0, G_OPTION_ARG_NONE, &do_timed_exit, N_("Exit after a time (for debugging)"), NULL }, { "version", 0, 0, G_OPTION_ARG_NONE, &print_version, N_("Print GDM version"), NULL }, { NULL } }; bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR); textdomain (GETTEXT_PACKAGE); setlocale (LC_ALL, ""); ret = 1; context = g_option_context_new (_("GNOME Display Manager")); g_option_context_add_main_entries (context, entries, NULL); g_option_context_set_ignore_unknown_options (context, TRUE); error = NULL; res = g_option_context_parse (context, &argc, &argv, &error); g_option_context_free (context); if (! res) { g_warning ("%s", error->message); g_error_free (error); goto out; } if (print_version) { g_print ("GDM %s\n", VERSION); exit (1); } if (fatal_warnings) { GLogLevelFlags fatal_mask; fatal_mask = g_log_set_always_fatal (G_LOG_FATAL_MASK); fatal_mask |= G_LOG_LEVEL_WARNING | G_LOG_LEVEL_CRITICAL; g_log_set_always_fatal (fatal_mask); } gdm_log_init (); settings = gdm_settings_new (); if (settings == NULL) { g_warning ("Unable to initialize settings"); goto out; } if (! gdm_settings_direct_init (settings, DATADIR "/gdm/gdm.schemas", "/")) { g_warning ("Unable to initialize settings"); goto out; } gdm_log_set_debug (is_debug_set ()); gdm_daemon_lookup_user (&gdm_uid, &gdm_gid); gdm_daemon_ensure_dirs (gdm_uid, gdm_gid); /* XDM compliant error message */ if (getuid () != 0) { /* make sure the pid file doesn't get wiped */ g_warning (_("Only the root user can run GDM")); exit (-1); } /* Connect to the bus, own the name and start the manager */ bus_reconnect (); /* pid file */ delete_pid (); write_pid (); /* clean up any stale ran once marker file that may be lingering */ delete_first_run_marker (); g_chdir (AUTHDIR); main_loop = g_main_loop_new (NULL, FALSE); g_unix_signal_add (SIGTERM, on_shutdown_signal_cb, main_loop); g_unix_signal_add (SIGINT, on_shutdown_signal_cb, main_loop); g_unix_signal_add (SIGHUP, on_sighup_cb, NULL); g_unix_signal_add (SIGUSR1, on_sigusr1_cb, NULL); if (do_timed_exit) { g_timeout_add_seconds (30, (GSourceFunc) timed_exit_cb, main_loop); } g_main_loop_run (main_loop); g_debug ("GDM finished, cleaning up..."); g_clear_object (&manager); g_clear_object (&settings); gdm_settings_direct_shutdown (); gdm_log_shutdown (); g_main_loop_unref (main_loop); ret = 0; out: if (error) { g_printerr ("%s\n", error->message); g_clear_error (&error); } return ret; } static void on_name_acquired (GDBusConnection *bus, const char *name, gpointer user_data) { gboolean xdmcp_enabled; manager = gdm_manager_new (); if (manager == NULL) { g_warning ("Could not construct manager object"); exit (1); } g_debug ("Successfully connected to D-Bus"); gdm_manager_start (manager); xdmcp_enabled = FALSE; gdm_settings_direct_get_boolean (GDM_KEY_XDMCP_ENABLE, &xdmcp_enabled); gdm_manager_set_xdmcp_enabled (manager, xdmcp_enabled); } static void on_name_lost (GDBusConnection *bus, const char *name, gpointer user_data) { g_debug ("Lost GDM name on bus"); bus_connection_closed (); } static gboolean bus_reconnect () { GDBusConnection *bus; gboolean ret; ret = TRUE; bus = get_system_bus (); if (bus == NULL) { goto out; } name_id = g_bus_own_name_on_connection (bus, GDM_DBUS_NAME, G_BUS_NAME_OWNER_FLAGS_NONE, on_name_acquired, on_name_lost, NULL, NULL); ret = FALSE; out: return ret; }