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-rw-r--r--common/gdm-common.c976
1 files changed, 976 insertions, 0 deletions
diff --git a/common/gdm-common.c b/common/gdm-common.c
new file mode 100644
index 0000000..b8de755
--- /dev/null
+++ b/common/gdm-common.c
@@ -0,0 +1,976 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "config.h"
+
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <grp.h>
+#include <pwd.h>
+
+#include <glib.h>
+#include <glib/gi18n.h>
+#include <glib/gstdio.h>
+#include <gio/gio.h>
+
+#include "gdm-common.h"
+
+#include <systemd/sd-login.h>
+
+#define GDM_DBUS_NAME "org.gnome.DisplayManager"
+#define GDM_DBUS_LOCAL_DISPLAY_FACTORY_PATH "/org/gnome/DisplayManager/LocalDisplayFactory"
+#define GDM_DBUS_LOCAL_DISPLAY_FACTORY_INTERFACE "org.gnome.DisplayManager.LocalDisplayFactory"
+
+G_DEFINE_QUARK (gdm-common-error, gdm_common_error);
+
+gboolean
+gdm_clear_close_on_exec_flag (int fd)
+{
+ int flags;
+
+ if (fd < 0) {
+ return FALSE;
+ }
+
+ flags = fcntl (fd, F_GETFD, 0);
+
+ if (flags < 0) {
+ return FALSE;
+ }
+
+ if ((flags & FD_CLOEXEC) != 0) {
+ int status;
+
+ status = fcntl (fd, F_SETFD, flags & ~FD_CLOEXEC);
+
+ return status != -1;
+ }
+
+ return TRUE;
+}
+
+gboolean
+gdm_get_pwent_for_name (const char *name,
+ struct passwd **pwentp)
+{
+ struct passwd *pwent;
+
+ do {
+ errno = 0;
+ pwent = getpwnam (name);
+ } while (pwent == NULL && errno == EINTR);
+
+ if (pwentp != NULL) {
+ *pwentp = pwent;
+ }
+
+ return (pwent != NULL);
+}
+
+static gboolean
+gdm_get_grent_for_gid (gint gid,
+ struct group **grentp)
+{
+ struct group *grent;
+
+ do {
+ errno = 0;
+ grent = getgrgid (gid);
+ } while (grent == NULL && errno == EINTR);
+
+ if (grentp != NULL) {
+ *grentp = grent;
+ }
+
+ return (grent != NULL);
+}
+
+int
+gdm_wait_on_and_disown_pid (int pid,
+ int timeout)
+{
+ int status;
+ int ret;
+ int num_tries;
+ int flags;
+ gboolean already_reaped;
+
+ if (timeout > 0) {
+ flags = WNOHANG;
+ num_tries = 10 * timeout;
+ } else {
+ flags = 0;
+ num_tries = 0;
+ }
+ wait_again:
+ errno = 0;
+ already_reaped = FALSE;
+ ret = waitpid (pid, &status, flags);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto wait_again;
+ } else if (errno == ECHILD) {
+ already_reaped = TRUE;
+ } else {
+ g_debug ("GdmCommon: waitpid () should not fail");
+ }
+ } else if (ret == 0) {
+ num_tries--;
+
+ if (num_tries > 0) {
+ g_usleep (G_USEC_PER_SEC / 10);
+ } else {
+ char *path;
+ char *command;
+
+ path = g_strdup_printf ("/proc/%ld/cmdline", (long) pid);
+ if (g_file_get_contents (path, &command, NULL, NULL)) {;
+ g_warning ("GdmCommon: process (pid:%d, command '%s') isn't dying after %d seconds, now ignoring it.",
+ (int) pid, command, timeout);
+ g_free (command);
+ } else {
+ g_warning ("GdmCommon: process (pid:%d) isn't dying after %d seconds, now ignoring it.",
+ (int) pid, timeout);
+ }
+ g_free (path);
+
+ return 0;
+ }
+ goto wait_again;
+ }
+
+ g_debug ("GdmCommon: process (pid:%d) done (%s:%d)",
+ (int) pid,
+ already_reaped? "reaped earlier" :
+ WIFEXITED (status) ? "status"
+ : WIFSIGNALED (status) ? "signal"
+ : "unknown",
+ already_reaped? 1 :
+ WIFEXITED (status) ? WEXITSTATUS (status)
+ : WIFSIGNALED (status) ? WTERMSIG (status)
+ : -1);
+
+ return status;
+}
+
+int
+gdm_wait_on_pid (int pid)
+{
+ return gdm_wait_on_and_disown_pid (pid, 0);
+}
+
+int
+gdm_signal_pid (int pid,
+ int signal)
+{
+ int status = -1;
+
+ /* perhaps block sigchld */
+ g_debug ("GdmCommon: sending signal %d to process %d", signal, pid);
+ errno = 0;
+ status = kill (pid, signal);
+
+ if (status < 0) {
+ if (errno == ESRCH) {
+ g_warning ("Child process %d was already dead.",
+ (int)pid);
+ } else {
+ g_warning ("Couldn't kill child process %d: %s",
+ pid,
+ g_strerror (errno));
+ }
+ }
+
+ /* perhaps unblock sigchld */
+
+ return status;
+}
+
+static gboolean
+_fd_is_character_device (int fd)
+{
+ struct stat file_info;
+
+ if (fstat (fd, &file_info) < 0) {
+ return FALSE;
+ }
+
+ return S_ISCHR (file_info.st_mode);
+}
+
+static gboolean
+_read_bytes (int fd,
+ char *bytes,
+ gsize number_of_bytes,
+ GError **error)
+{
+ size_t bytes_left_to_read;
+ size_t total_bytes_read = 0;
+ gboolean premature_eof;
+
+ bytes_left_to_read = number_of_bytes;
+ premature_eof = FALSE;
+ do {
+ size_t bytes_read = 0;
+
+ errno = 0;
+ bytes_read = read (fd, ((guchar *) bytes) + total_bytes_read,
+ bytes_left_to_read);
+
+ if (bytes_read > 0) {
+ total_bytes_read += bytes_read;
+ bytes_left_to_read -= bytes_read;
+ } else if (bytes_read == 0) {
+ premature_eof = TRUE;
+ break;
+ } else if ((errno != EINTR)) {
+ break;
+ }
+ } while (bytes_left_to_read > 0);
+
+ if (premature_eof) {
+ g_set_error (error,
+ G_FILE_ERROR,
+ G_FILE_ERROR_FAILED,
+ "No data available");
+
+ return FALSE;
+ } else if (bytes_left_to_read > 0) {
+ g_set_error (error,
+ G_FILE_ERROR,
+ g_file_error_from_errno (errno),
+ "%s", g_strerror (errno));
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ * Pulls a requested number of bytes from /dev/urandom
+ *
+ * @param size number of bytes to pull
+ * @param error error if read fails
+ * @returns The requested number of random bytes or #NULL if fail
+ */
+
+char *
+gdm_generate_random_bytes (gsize size,
+ GError **error)
+{
+ int fd;
+ char *bytes;
+ GError *read_error;
+
+ /* We don't use the g_rand_* glib apis because they don't document
+ * how much entropy they are seeded with, and it might be less
+ * than the passed in size.
+ */
+
+ errno = 0;
+ fd = open ("/dev/urandom", O_RDONLY);
+
+ if (fd < 0) {
+ g_set_error (error,
+ G_FILE_ERROR,
+ g_file_error_from_errno (errno),
+ "%s", g_strerror (errno));
+ close (fd);
+ return NULL;
+ }
+
+ if (!_fd_is_character_device (fd)) {
+ g_set_error (error,
+ G_FILE_ERROR,
+ g_file_error_from_errno (ENODEV),
+ _("/dev/urandom is not a character device"));
+ close (fd);
+ return NULL;
+ }
+
+ bytes = g_malloc (size);
+ read_error = NULL;
+ if (!_read_bytes (fd, bytes, size, &read_error)) {
+ g_propagate_error (error, read_error);
+ g_free (bytes);
+ close (fd);
+ return NULL;
+ }
+
+ close (fd);
+ return bytes;
+}
+static gboolean
+create_transient_display (GDBusConnection *connection,
+ GError **error)
+{
+ GError *local_error = NULL;
+ GVariant *reply;
+ const char *value;
+
+ reply = g_dbus_connection_call_sync (connection,
+ GDM_DBUS_NAME,
+ GDM_DBUS_LOCAL_DISPLAY_FACTORY_PATH,
+ GDM_DBUS_LOCAL_DISPLAY_FACTORY_INTERFACE,
+ "CreateTransientDisplay",
+ NULL, /* parameters */
+ G_VARIANT_TYPE ("(o)"),
+ G_DBUS_CALL_FLAGS_NONE,
+ -1,
+ NULL, &local_error);
+ if (reply == NULL) {
+ g_warning ("Unable to create transient display: %s", local_error->message);
+ g_propagate_error (error, local_error);
+ return FALSE;
+ }
+
+ g_variant_get (reply, "(&o)", &value);
+ g_debug ("Started %s", value);
+
+ g_variant_unref (reply);
+ return TRUE;
+}
+
+gboolean
+gdm_activate_session_by_id (GDBusConnection *connection,
+ const char *seat_id,
+ const char *session_id)
+{
+ GError *local_error = NULL;
+ GVariant *reply;
+
+ reply = g_dbus_connection_call_sync (connection,
+ "org.freedesktop.login1",
+ "/org/freedesktop/login1",
+ "org.freedesktop.login1.Manager",
+ "ActivateSessionOnSeat",
+ g_variant_new ("(ss)", session_id, seat_id),
+ NULL,
+ G_DBUS_CALL_FLAGS_NONE,
+ -1,
+ NULL, &local_error);
+ if (reply == NULL) {
+ g_warning ("Unable to activate session: %s", local_error->message);
+ g_error_free (local_error);
+ return FALSE;
+ }
+
+ g_variant_unref (reply);
+
+ return TRUE;
+}
+
+gboolean
+gdm_get_login_window_session_id (const char *seat_id,
+ char **session_id)
+{
+ gboolean ret;
+ int res, i;
+ char **sessions;
+ char *service_id;
+ char *service_class;
+ char *state;
+
+ res = sd_seat_get_sessions (seat_id, &sessions, NULL, NULL);
+ if (res < 0) {
+ g_debug ("Failed to determine sessions: %s", strerror (-res));
+ return FALSE;
+ }
+
+ if (sessions == NULL || sessions[0] == NULL) {
+ *session_id = NULL;
+ ret = FALSE;
+ goto out;
+ }
+
+ for (i = 0; sessions[i]; i ++) {
+
+ res = sd_session_get_class (sessions[i], &service_class);
+ if (res < 0) {
+ if (res == -ENXIO)
+ continue;
+
+ g_debug ("failed to determine class of session %s: %s", sessions[i], strerror (-res));
+ ret = FALSE;
+ goto out;
+ }
+
+ if (strcmp (service_class, "greeter") != 0) {
+ free (service_class);
+ continue;
+ }
+
+ free (service_class);
+
+ ret = sd_session_get_state (sessions[i], &state);
+ if (ret < 0) {
+ if (res == -ENXIO)
+ continue;
+
+ g_debug ("failed to determine state of session %s: %s", sessions[i], strerror (-res));
+ ret = FALSE;
+ goto out;
+ }
+
+ if (g_strcmp0 (state, "closing") == 0) {
+ free (state);
+ continue;
+ }
+ free (state);
+
+ res = sd_session_get_service (sessions[i], &service_id);
+ if (res < 0) {
+ if (res == -ENXIO)
+ continue;
+
+ g_debug ("failed to determine service of session %s: %s", sessions[i], strerror (-res));
+ ret = FALSE;
+ goto out;
+ }
+
+ if (strcmp (service_id, "gdm-launch-environment") == 0) {
+ *session_id = g_strdup (sessions[i]);
+ ret = TRUE;
+
+ free (service_id);
+ goto out;
+ }
+
+ free (service_id);
+ }
+
+ *session_id = NULL;
+ ret = FALSE;
+
+out:
+ if (sessions) {
+ for (i = 0; sessions[i]; i ++) {
+ free (sessions[i]);
+ }
+
+ free (sessions);
+ }
+
+ return ret;
+}
+
+static gboolean
+goto_login_session (GDBusConnection *connection,
+ GError **error)
+{
+ gboolean ret;
+ int res;
+ char *our_session;
+ char *session_id;
+ char *seat_id;
+ GError *local_error = NULL;
+
+ ret = FALSE;
+ session_id = NULL;
+ seat_id = NULL;
+
+ /* First look for any existing LoginWindow sessions on the seat.
+ If none are found, create a new one. */
+
+ /* Note that we mostly use free () here, instead of g_free ()
+ * since the data allocated is from libsystemd-logind, which
+ * does not use GLib's g_malloc (). */
+
+ if (!gdm_find_display_session (0, getuid (), &our_session, &local_error)) {
+ g_propagate_prefixed_error (error, local_error, _("Could not identify the current session: "));
+
+ return FALSE;
+ }
+
+ res = sd_session_get_seat (our_session, &seat_id);
+ free (our_session);
+ if (res < 0) {
+ g_debug ("failed to determine own seat: %s", strerror (-res));
+ g_set_error (error, GDM_COMMON_ERROR, 0, _("Could not identify the current seat."));
+
+ return FALSE;
+ }
+
+ res = sd_seat_can_multi_session (seat_id);
+ if (res < 0) {
+ free (seat_id);
+
+ g_debug ("failed to determine whether seat can do multi session: %s", strerror (-res));
+ g_set_error (error, GDM_COMMON_ERROR, 0, _("The system is unable to determine whether to switch to an existing login screen or start up a new login screen."));
+
+ return FALSE;
+ }
+
+ if (res == 0) {
+ free (seat_id);
+
+ g_set_error (error, GDM_COMMON_ERROR, 0, _("The system is unable to start up a new login screen."));
+
+ return FALSE;
+ }
+
+ res = gdm_get_login_window_session_id (seat_id, &session_id);
+ if (res && session_id != NULL) {
+ res = gdm_activate_session_by_id (connection, seat_id, session_id);
+
+ if (res) {
+ ret = TRUE;
+ }
+ }
+
+ if (! ret && g_strcmp0 (seat_id, "seat0") == 0) {
+ res = create_transient_display (connection, error);
+ if (res) {
+ ret = TRUE;
+ }
+ }
+
+ free (seat_id);
+ g_free (session_id);
+
+ return ret;
+}
+
+gboolean
+gdm_goto_login_session (GError **error)
+{
+ GError *local_error;
+ GDBusConnection *connection;
+
+ local_error = NULL;
+ connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, NULL, &local_error);
+ if (connection == NULL) {
+ g_debug ("Failed to connect to the D-Bus daemon: %s", local_error->message);
+ g_propagate_error (error, local_error);
+ return FALSE;
+ }
+
+ return goto_login_session (connection, error);
+}
+
+static void
+listify_hash (const char *key,
+ const char *value,
+ GPtrArray *env)
+{
+ char *str;
+ str = g_strdup_printf ("%s=%s", key, value);
+ g_debug ("Gdm: script environment: %s", str);
+ g_ptr_array_add (env, str);
+}
+
+GPtrArray *
+gdm_get_script_environment (const char *username,
+ const char *display_name,
+ const char *display_hostname,
+ const char *display_x11_authority_file)
+{
+ GPtrArray *env;
+ GHashTable *hash;
+ struct passwd *pwent;
+
+ env = g_ptr_array_new ();
+
+ /* create a hash table of current environment, then update keys has necessary */
+ hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+
+ /* modify environment here */
+ g_hash_table_insert (hash, g_strdup ("HOME"), g_strdup ("/"));
+ g_hash_table_insert (hash, g_strdup ("PWD"), g_strdup ("/"));
+ g_hash_table_insert (hash, g_strdup ("SHELL"), g_strdup ("/bin/sh"));
+
+ if (username != NULL) {
+ g_hash_table_insert (hash, g_strdup ("LOGNAME"),
+ g_strdup (username));
+ g_hash_table_insert (hash, g_strdup ("USER"),
+ g_strdup (username));
+ g_hash_table_insert (hash, g_strdup ("USERNAME"),
+ g_strdup (username));
+
+ gdm_get_pwent_for_name (username, &pwent);
+ if (pwent != NULL) {
+ if (pwent->pw_dir != NULL && pwent->pw_dir[0] != '\0') {
+ g_hash_table_insert (hash, g_strdup ("HOME"),
+ g_strdup (pwent->pw_dir));
+ g_hash_table_insert (hash, g_strdup ("PWD"),
+ g_strdup (pwent->pw_dir));
+ }
+
+ g_hash_table_insert (hash, g_strdup ("SHELL"),
+ g_strdup (pwent->pw_shell));
+
+ /* Also get group name and propagate down */
+ struct group *grent;
+
+ if (gdm_get_grent_for_gid (pwent->pw_gid, &grent)) {
+ g_hash_table_insert (hash, g_strdup ("GROUP"), g_strdup (grent->gr_name));
+ }
+ }
+ }
+
+ if (display_hostname) {
+ g_hash_table_insert (hash, g_strdup ("REMOTE_HOST"), g_strdup (display_hostname));
+ }
+
+ /* Runs as root */
+ if (display_x11_authority_file) {
+ g_hash_table_insert (hash, g_strdup ("XAUTHORITY"), g_strdup (display_x11_authority_file));
+ }
+
+ if (display_name) {
+ g_hash_table_insert (hash, g_strdup ("DISPLAY"), g_strdup (display_name));
+ }
+ g_hash_table_insert (hash, g_strdup ("PATH"), g_strdup (GDM_SESSION_DEFAULT_PATH));
+ g_hash_table_insert (hash, g_strdup ("RUNNING_UNDER_GDM"), g_strdup ("true"));
+
+ g_hash_table_remove (hash, "MAIL");
+
+ g_hash_table_foreach (hash, (GHFunc)listify_hash, env);
+ g_hash_table_destroy (hash);
+
+ g_ptr_array_add (env, NULL);
+
+ return env;
+}
+
+gboolean
+gdm_run_script (const char *dir,
+ const char *username,
+ const char *display_name,
+ const char *display_hostname,
+ const char *display_x11_authority_file)
+{
+ char *script;
+ char **argv;
+ gint status;
+ GError *error;
+ GPtrArray *env;
+ gboolean res;
+ gboolean ret;
+
+ ret = FALSE;
+
+ g_assert (dir != NULL);
+ g_assert (username != NULL);
+
+ script = g_build_filename (dir, display_name, NULL);
+ g_debug ("Trying script %s", script);
+ if (! (g_file_test (script, G_FILE_TEST_IS_REGULAR)
+ && g_file_test (script, G_FILE_TEST_IS_EXECUTABLE))) {
+ g_debug ("script %s not found; skipping", script);
+ g_free (script);
+ script = NULL;
+ }
+
+ if (script == NULL
+ && display_hostname != NULL
+ && display_hostname[0] != '\0') {
+ script = g_build_filename (dir, display_hostname, NULL);
+ g_debug ("Trying script %s", script);
+ if (! (g_file_test (script, G_FILE_TEST_IS_REGULAR)
+ && g_file_test (script, G_FILE_TEST_IS_EXECUTABLE))) {
+ g_debug ("script %s not found; skipping", script);
+ g_free (script);
+ script = NULL;
+ }
+ }
+
+ if (script == NULL) {
+ script = g_build_filename (dir, "Default", NULL);
+ g_debug ("Trying script %s", script);
+ if (! (g_file_test (script, G_FILE_TEST_IS_REGULAR)
+ && g_file_test (script, G_FILE_TEST_IS_EXECUTABLE))) {
+ g_debug ("script %s not found; skipping", script);
+ g_free (script);
+ script = NULL;
+ }
+ }
+
+ if (script == NULL) {
+ g_debug ("no script found");
+ return TRUE;
+ }
+
+ g_debug ("Running process: %s", script);
+ error = NULL;
+ if (! g_shell_parse_argv (script, NULL, &argv, &error)) {
+ g_warning ("Could not parse command: %s", error->message);
+ g_error_free (error);
+ goto out;
+ }
+
+ env = gdm_get_script_environment (username,
+ display_name,
+ display_hostname,
+ display_x11_authority_file);
+
+ res = g_spawn_sync (NULL,
+ argv,
+ (char **)env->pdata,
+ G_SPAWN_SEARCH_PATH,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ &status,
+ &error);
+
+ g_ptr_array_foreach (env, (GFunc)g_free, NULL);
+ g_ptr_array_free (env, TRUE);
+ g_strfreev (argv);
+
+ if (! res) {
+ g_warning ("Unable to run script: %s", error->message);
+ g_error_free (error);
+ }
+
+ if (WIFEXITED (status)) {
+ g_debug ("Process exit status: %d", WEXITSTATUS (status));
+ ret = WEXITSTATUS (status) == 0;
+ }
+
+ out:
+ g_free (script);
+
+ return ret;
+}
+
+gboolean
+gdm_shell_var_is_valid_char (gchar c, gboolean first)
+{
+ return (!first && g_ascii_isdigit (c)) ||
+ c == '_' ||
+ g_ascii_isalpha (c);
+}
+
+/* This expands a string somewhat similar to how a shell would do it
+ if it was enclosed inside double quotes. It handles variable
+ expansion like $FOO and ${FOO}, single-char escapes using \, and
+ non-escaped # at the begining of a word is taken as a comment and ignored */
+char *
+gdm_shell_expand (const char *str,
+ GdmExpandVarFunc expand_var_func,
+ gpointer user_data)
+{
+ GString *s = g_string_new("");
+ const gchar *p, *start;
+ gchar c;
+ gboolean at_new_word;
+
+ p = str;
+ at_new_word = TRUE;
+ while (*p) {
+ c = *p;
+ if (c == '\\') {
+ p++;
+ c = *p;
+ if (c != '\0') {
+ p++;
+ switch (c) {
+ case '\\':
+ g_string_append_c (s, '\\');
+ break;
+ case '$':
+ g_string_append_c (s, '$');
+ break;
+ case '#':
+ g_string_append_c (s, '#');
+ break;
+ default:
+ g_string_append_c (s, '\\');
+ g_string_append_c (s, c);
+ break;
+ }
+ }
+ } else if (c == '#' && at_new_word) {
+ break;
+ } else if (c == '$') {
+ gboolean brackets = FALSE;
+ p++;
+ if (*p == '{') {
+ brackets = TRUE;
+ p++;
+ }
+ start = p;
+ while (*p != '\0' &&
+ gdm_shell_var_is_valid_char (*p, p == start))
+ p++;
+ if (p == start || (brackets && *p != '}')) {
+ /* Invalid variable, use as-is */
+ g_string_append_c (s, '$');
+ if (brackets)
+ g_string_append_c (s, '{');
+ g_string_append_len (s, start, p - start);
+ } else {
+ gchar *expanded;
+ gchar *var = g_strndup (start, p - start);
+ if (brackets && *p == '}')
+ p++;
+
+ expanded = expand_var_func (var, user_data);
+ if (expanded)
+ g_string_append (s, expanded);
+ g_free (var);
+ g_free (expanded);
+ }
+ } else {
+ p++;
+ g_string_append_c (s, c);
+ at_new_word = g_ascii_isspace (c);
+ }
+ }
+ return g_string_free (s, FALSE);
+}
+
+static gboolean
+_systemd_session_is_graphical (const char *session_id)
+{
+ const gchar * const graphical_session_types[] = { "wayland", "x11", "mir", NULL };
+ int saved_errno;
+ g_autofree gchar *type = NULL;
+
+ saved_errno = sd_session_get_type (session_id, &type);
+ if (saved_errno < 0) {
+ g_warning ("Couldn't get type for session '%s': %s",
+ session_id,
+ g_strerror (-saved_errno));
+ return FALSE;
+ }
+
+ if (!g_strv_contains (graphical_session_types, type)) {
+ g_debug ("Session '%s' is not a graphical session (type: '%s')",
+ session_id,
+ type);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static gboolean
+_systemd_session_is_active (const char *session_id)
+{
+ const gchar * const active_states[] = { "active", "online", NULL };
+ int saved_errno;
+ g_autofree gchar *state = NULL;
+
+ /*
+ * display sessions can be 'closing' if they are logged out but some
+ * processes are lingering; we shouldn't consider these (this is
+ * checking for a race condition since we specified
+ * GDM_SYSTEMD_SESSION_REQUIRE_ONLINE)
+ */
+ saved_errno = sd_session_get_state (session_id, &state);
+ if (saved_errno < 0) {
+ g_warning ("Couldn't get state for session '%s': %s",
+ session_id,
+ g_strerror (-saved_errno));
+ return FALSE;
+ }
+
+ if (!g_strv_contains (active_states, state)) {
+ g_debug ("Session '%s' is not active or online", session_id);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+gboolean
+gdm_find_display_session (GPid pid,
+ const uid_t uid,
+ char **out_session_id,
+ GError **error)
+{
+ char *local_session_id = NULL;
+ g_auto(GStrv) sessions = NULL;
+ int n_sessions;
+ int res;
+
+ g_return_val_if_fail (out_session_id != NULL, FALSE);
+
+ /* First try to look up the session using the pid. We need this
+ * at least for the greeter, because it currently runs multiple
+ * sessions under the same user.
+ * See also commit 2b52d8933c8ab38e7ee83318da2363d00d8c5581
+ * which added an explicit dbus-run-session for all but seat0.
+ */
+ res = sd_pid_get_session (pid, &local_session_id);
+ if (res >= 0) {
+ g_debug ("GdmCommon: Found session %s for PID %d, using", local_session_id, pid);
+
+ *out_session_id = g_strdup (local_session_id);
+ free (local_session_id);
+
+ return TRUE;
+ } else {
+ if (res != -ENODATA)
+ g_warning ("GdmCommon: Failed to retrieve session information for pid %d: %s",
+ pid, strerror (-res));
+ }
+
+ g_debug ("Finding a graphical session for user %d", uid);
+
+ n_sessions = sd_uid_get_sessions (uid,
+ GDM_SYSTEMD_SESSION_REQUIRE_ONLINE,
+ &sessions);
+
+ if (n_sessions < 0) {
+ g_set_error (error,
+ GDM_COMMON_ERROR,
+ 0,
+ "Failed to get sessions for user %d",
+ uid);
+ return FALSE;
+ }
+
+ for (int i = 0; i < n_sessions; ++i) {
+ g_debug ("Considering session '%s'", sessions[i]);
+
+ if (!_systemd_session_is_graphical (sessions[i]))
+ continue;
+
+ if (!_systemd_session_is_active (sessions[i]))
+ continue;
+
+ /*
+ * We get the sessions from newest to oldest, so take the last
+ * one we find that's good
+ */
+ local_session_id = sessions[i];
+ }
+
+ if (local_session_id == NULL) {
+ g_set_error (error,
+ GDM_COMMON_ERROR,
+ 0,
+ "Could not find a graphical session for user %d",
+ uid);
+ return FALSE;
+ }
+
+ *out_session_id = g_strdup (local_session_id);
+
+ return TRUE;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 16:59:17 +0000