Program: CWE-22
Project: CVE-2022-23082
Buggy source:
/*
 * Copyright © 2014-2018 Red Hat, Inc
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *       Alexander Larsson <alexl@redhat.com>
 */

#include "config.h"

#include <string.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/personality.h>
#include <grp.h>
#include <unistd.h>
#include <gio/gunixfdlist.h>

#include <glib/gi18n-lib.h>

#include <gio/gio.h>
#include "libglnx/libglnx.h"

#include "flatpak-run-private.h"
#include "flatpak-proxy.h"
#include "flatpak-utils-private.h"
#include "flatpak-dir-private.h"
#include "flatpak-systemd-dbus-generated.h"
#include "flatpak-error.h"

/* Same order as enum */
const char *flatpak_context_shares[] = {
  "network",
  "ipc",
  NULL
};

/* Same order as enum */
const char *flatpak_context_sockets[] = {
  "x11",
  "wayland",
  "pulseaudio",
  "session-bus",
  "system-bus",
  "fallback-x11",
  "ssh-auth",
  "pcsc",
  "cups",
  NULL
};

const char *flatpak_context_devices[] = {
  "dri",
  "all",
  "kvm",
  "shm",
  NULL
};

const char *flatpak_context_features[] = {
  "devel",
  "multiarch",
  "bluetooth",
  "canbus",
  "per-app-dev-shm",
  NULL
};

const char *flatpak_context_special_filesystems[] = {
  "home",
  "host",
  "host-etc",
  "host-os",
  NULL
};

FlatpakContext *
flatpak_context_new (void)
{
  FlatpakContext *context;

  context = g_slice_new0 (FlatpakContext);
  context->env_vars = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
  context->persistent = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  /* filename or special filesystem name => FlatpakFilesystemMode */
  context->filesystems = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->session_bus_policy = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->system_bus_policy = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->generic_policy = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                   g_free, (GDestroyNotify) g_strfreev);

  return context;
}

void
flatpak_context_free (FlatpakContext *context)
{
  g_hash_table_destroy (context->env_vars);
  g_hash_table_destroy (context->persistent);
  g_hash_table_destroy (context->filesystems);
  g_hash_table_destroy (context->session_bus_policy);
  g_hash_table_destroy (context->system_bus_policy);
  g_hash_table_destroy (context->generic_policy);
  g_slice_free (FlatpakContext, context);
}

static guint32
flatpak_context_bitmask_from_string (const char *name, const char **names)
{
  guint32 i;

  for (i = 0; names[i] != NULL; i++)
    {
      if (strcmp (names[i], name) == 0)
        return 1 << i;
    }

  return 0;
}

static char **
flatpak_context_bitmask_to_string (guint32 enabled, guint32 valid, const char **names)
{
  guint32 i;
  GPtrArray *array;

  array = g_ptr_array_new ();

  for (i = 0; names[i] != NULL; i++)
    {
      guint32 bitmask = 1 << i;
      if (valid & bitmask)
        {
          if (enabled & bitmask)
            g_ptr_array_add (array, g_strdup (names[i]));
          else
            g_ptr_array_add (array, g_strdup_printf ("!%s", names[i]));
        }
    }

  g_ptr_array_add (array, NULL);
  return (char **) g_ptr_array_free (array, FALSE);
}

static void
flatpak_context_bitmask_to_args (guint32 enabled, guint32 valid, const char **names,
                                 const char *enable_arg, const char *disable_arg,
                                 GPtrArray *args)
{
  guint32 i;

  for (i = 0; names[i] != NULL; i++)
    {
      guint32 bitmask = 1 << i;
      if (valid & bitmask)
        {
          if (enabled & bitmask)
            g_ptr_array_add (args, g_strdup_printf ("%s=%s", enable_arg, names[i]));
          else
            g_ptr_array_add (args, g_strdup_printf ("%s=%s", disable_arg, names[i]));
        }
    }
}


static FlatpakContextShares
flatpak_context_share_from_string (const char *string, GError **error)
{
  FlatpakContextShares shares = flatpak_context_bitmask_from_string (string, flatpak_context_shares);

  if (shares == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_shares);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown share type %s, valid types are: %s"), string, values);
    }

  return shares;
}

static char **
flatpak_context_shared_to_string (FlatpakContextShares shares, FlatpakContextShares valid)
{
  return flatpak_context_bitmask_to_string (shares, valid, flatpak_context_shares);
}

static void
flatpak_context_shared_to_args (FlatpakContextShares shares,
                                FlatpakContextShares valid,
                                GPtrArray           *args)
{
  return flatpak_context_bitmask_to_args (shares, valid, flatpak_context_shares, "--share", "--unshare", args);
}

static FlatpakPolicy
flatpak_policy_from_string (const char *string, GError **error)
{
  const char *policies[] = { "none", "see", "talk", "own", NULL };
  int i;
  g_autofree char *values = NULL;

  for (i = 0; policies[i]; i++)
    {
      if (strcmp (string, policies[i]) == 0)
        return i;
    }

  values = g_strjoinv (", ", (char **) policies);
  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Unknown policy type %s, valid types are: %s"), string, values);

  return -1;
}

static const char *
flatpak_policy_to_string (FlatpakPolicy policy)
{
  if (policy == FLATPAK_POLICY_SEE)
    return "see";
  if (policy == FLATPAK_POLICY_TALK)
    return "talk";
  if (policy == FLATPAK_POLICY_OWN)
    return "own";

  return "none";
}

static gboolean
flatpak_verify_dbus_name (const char *name, GError **error)
{
  const char *name_part;
  g_autofree char *tmp = NULL;

  if (g_str_has_suffix (name, ".*"))
    {
      tmp = g_strndup (name, strlen (name) - 2);
      name_part = tmp;
    }
  else
    {
      name_part = name;
    }

  if (g_dbus_is_name (name_part) && !g_dbus_is_unique_name (name_part))
    return TRUE;

  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Invalid dbus name %s"), name);
  return FALSE;
}

static FlatpakContextSockets
flatpak_context_socket_from_string (const char *string, GError **error)
{
  FlatpakContextSockets sockets = flatpak_context_bitmask_from_string (string, flatpak_context_sockets);

  if (sockets == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_sockets);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown socket type %s, valid types are: %s"), string, values);
    }

  return sockets;
}

static char **
flatpak_context_sockets_to_string (FlatpakContextSockets sockets, FlatpakContextSockets valid)
{
  return flatpak_context_bitmask_to_string (sockets, valid, flatpak_context_sockets);
}

static void
flatpak_context_sockets_to_args (FlatpakContextSockets sockets,
                                 FlatpakContextSockets valid,
                                 GPtrArray            *args)
{
  return flatpak_context_bitmask_to_args (sockets, valid, flatpak_context_sockets, "--socket", "--nosocket", args);
}

static FlatpakContextDevices
flatpak_context_device_from_string (const char *string, GError **error)
{
  FlatpakContextDevices devices = flatpak_context_bitmask_from_string (string, flatpak_context_devices);

  if (devices == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_devices);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown device type %s, valid types are: %s"), string, values);
    }
  return devices;
}

static char **
flatpak_context_devices_to_string (FlatpakContextDevices devices, FlatpakContextDevices valid)
{
  return flatpak_context_bitmask_to_string (devices, valid, flatpak_context_devices);
}

static void
flatpak_context_devices_to_args (FlatpakContextDevices devices,
                                 FlatpakContextDevices valid,
                                 GPtrArray            *args)
{
  return flatpak_context_bitmask_to_args (devices, valid, flatpak_context_devices, "--device", "--nodevice", args);
}

static FlatpakContextFeatures
flatpak_context_feature_from_string (const char *string, GError **error)
{
  FlatpakContextFeatures feature = flatpak_context_bitmask_from_string (string, flatpak_context_features);

  if (feature == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_features);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown feature type %s, valid types are: %s"), string, values);
    }

  return feature;
}

static char **
flatpak_context_features_to_string (FlatpakContextFeatures features, FlatpakContextFeatures valid)
{
  return flatpak_context_bitmask_to_string (features, valid, flatpak_context_features);
}

static void
flatpak_context_features_to_args (FlatpakContextFeatures features,
                                  FlatpakContextFeatures valid,
                                  GPtrArray             *args)
{
  return flatpak_context_bitmask_to_args (features, valid, flatpak_context_features, "--allow", "--disallow", args);
}

static void
flatpak_context_add_shares (FlatpakContext      *context,
                            FlatpakContextShares shares)
{
  context->shares_valid |= shares;
  context->shares |= shares;
}

static void
flatpak_context_remove_shares (FlatpakContext      *context,
                               FlatpakContextShares shares)
{
  context->shares_valid |= shares;
  context->shares &= ~shares;
}

static void
flatpak_context_add_sockets (FlatpakContext       *context,
                             FlatpakContextSockets sockets)
{
  context->sockets_valid |= sockets;
  context->sockets |= sockets;
}

static void
flatpak_context_remove_sockets (FlatpakContext       *context,
                                FlatpakContextSockets sockets)
{
  context->sockets_valid |= sockets;
  context->sockets &= ~sockets;
}

static void
flatpak_context_add_devices (FlatpakContext       *context,
                             FlatpakContextDevices devices)
{
  context->devices_valid |= devices;
  context->devices |= devices;
}

static void
flatpak_context_remove_devices (FlatpakContext       *context,
                                FlatpakContextDevices devices)
{
  context->devices_valid |= devices;
  context->devices &= ~devices;
}

static void
flatpak_context_add_features (FlatpakContext        *context,
                              FlatpakContextFeatures features)
{
  context->features_valid |= features;
  context->features |= features;
}

static void
flatpak_context_remove_features (FlatpakContext        *context,
                                 FlatpakContextFeatures features)
{
  context->features_valid |= features;
  context->features &= ~features;
}

static void
flatpak_context_set_env_var (FlatpakContext *context,
                             const char     *name,
                             const char     *value)
{
  g_hash_table_insert (context->env_vars, g_strdup (name), g_strdup (value));
}

void
flatpak_context_set_session_bus_policy (FlatpakContext *context,
                                        const char     *name,
                                        FlatpakPolicy   policy)
{
  g_hash_table_insert (context->session_bus_policy, g_strdup (name), GINT_TO_POINTER (policy));
}

GStrv
flatpak_context_get_session_bus_policy_allowed_own_names (FlatpakContext *context)
{
  GHashTableIter iter;
  gpointer key, value;
  g_autoptr(GPtrArray) names = g_ptr_array_new_with_free_func (g_free);

  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    if (GPOINTER_TO_INT (value) == FLATPAK_POLICY_OWN)
      g_ptr_array_add (names, g_strdup (key));

  g_ptr_array_add (names, NULL);
  return (GStrv) g_ptr_array_free (g_steal_pointer (&names), FALSE);
}

void
flatpak_context_set_system_bus_policy (FlatpakContext *context,
                                       const char     *name,
                                       FlatpakPolicy   policy)
{
  g_hash_table_insert (context->system_bus_policy, g_strdup (name), GINT_TO_POINTER (policy));
}

static void
flatpak_context_apply_generic_policy (FlatpakContext *context,
                                      const char     *key,
                                      const char     *value)
{
  GPtrArray *new = g_ptr_array_new ();
  const char **old_v;
  int i;

  g_assert (strchr (key, '.') != NULL);

  old_v = g_hash_table_lookup (context->generic_policy, key);
  for (i = 0; old_v != NULL && old_v[i] != NULL; i++)
    {
      const char *old = old_v[i];
      const char *cmp1 = old;
      const char *cmp2 = value;
      if (*cmp1 == '!')
        cmp1++;
      if (*cmp2 == '!')
        cmp2++;
      if (strcmp (cmp1, cmp2) != 0)
        g_ptr_array_add (new, g_strdup (old));
    }

  g_ptr_array_add (new, g_strdup (value));
  g_ptr_array_add (new, NULL);

  g_hash_table_insert (context->generic_policy, g_strdup (key),
                       g_ptr_array_free (new, FALSE));
}

static void
flatpak_context_set_persistent (FlatpakContext *context,
                                const char     *path)
{
  g_hash_table_insert (context->persistent, g_strdup (path), GINT_TO_POINTER (1));
}

static gboolean
get_xdg_dir_from_prefix (const char  *prefix,
                         const char **where,
                         const char **dir)
{
  if (strcmp (prefix, "xdg-data") == 0)
    {
      if (where)
        *where = "data";
      if (dir)
        *dir = g_get_user_data_dir ();
      return TRUE;
    }
  if (strcmp (prefix, "xdg-cache") == 0)
    {
      if (where)
        *where = "cache";
      if (dir)
        *dir = g_get_user_cache_dir ();
      return TRUE;
    }
  if (strcmp (prefix, "xdg-config") == 0)
    {
      if (where)
        *where = "config";
      if (dir)
        *dir = g_get_user_config_dir ();
      return TRUE;
    }
  return FALSE;
}

/* This looks only in the xdg dirs (config, cache, data), not the user
   definable ones */
static char *
get_xdg_dir_from_string (const char  *filesystem,
                         const char **suffix,
                         const char **where)
{
  char *slash;
  const char *rest;
  g_autofree char *prefix = NULL;
  const char *dir = NULL;
  gsize len;

  slash = strchr (filesystem, '/');

  if (slash)
    len = slash - filesystem;
  else
    len = strlen (filesystem);

  rest = filesystem + len;
  while (*rest == '/')
    rest++;

  if (suffix != NULL)
    *suffix = rest;

  prefix = g_strndup (filesystem, len);

  if (get_xdg_dir_from_prefix (prefix, where, &dir))
    return g_build_filename (dir, rest, NULL);

  return NULL;
}

static gboolean
get_xdg_user_dir_from_string (const char  *filesystem,
                              const char **config_key,
                              const char **suffix,
                              const char **dir)
{
  char *slash;
  const char *rest;
  g_autofree char *prefix = NULL;
  gsize len;

  slash = strchr (filesystem, '/');

  if (slash)
    len = slash - filesystem;
  else
    len = strlen (filesystem);

  rest = filesystem + len;
  while (*rest == '/')
    rest++;

  if (suffix)
    *suffix = rest;

  prefix = g_strndup (filesystem, len);

  if (strcmp (prefix, "xdg-desktop") == 0)
    {
      if (config_key)
        *config_key = "XDG_DESKTOP_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DESKTOP);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-documents") == 0)
    {
      if (config_key)
        *config_key = "XDG_DOCUMENTS_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DOCUMENTS);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-download") == 0)
    {
      if (config_key)
        *config_key = "XDG_DOWNLOAD_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DOWNLOAD);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-music") == 0)
    {
      if (config_key)
        *config_key = "XDG_MUSIC_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_MUSIC);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-pictures") == 0)
    {
      if (config_key)
        *config_key = "XDG_PICTURES_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_PICTURES);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-public-share") == 0)
    {
      if (config_key)
        *config_key = "XDG_PUBLICSHARE_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_PUBLIC_SHARE);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-templates") == 0)
    {
      if (config_key)
        *config_key = "XDG_TEMPLATES_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_TEMPLATES);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-videos") == 0)
    {
      if (config_key)
        *config_key = "XDG_VIDEOS_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_VIDEOS);
      return TRUE;
    }
  if (get_xdg_dir_from_prefix (prefix, NULL, dir))
    {
      if (config_key)
        *config_key = NULL;
      return TRUE;
    }
  /* Don't support xdg-run without suffix, because that doesn't work */
  if (strcmp (prefix, "xdg-run") == 0 &&
      *rest != 0)
    {
      if (config_key)
        *config_key = NULL;
      if (dir)
        *dir = flatpak_get_real_xdg_runtime_dir ();
      return TRUE;
    }

  return FALSE;
}

static char *
unparse_filesystem_flags (const char           *path,
                          FlatpakFilesystemMode mode)
{
  g_autoptr(GString) s = g_string_new ("");
  const char *p;

  for (p = path; *p != 0; p++)
    {
      if (*p == ':')
        g_string_append (s, "\\:");
      else if (*p == '\\')
        g_string_append (s, "\\\\");
      else
        g_string_append_c (s, *p);
    }

  switch (mode)
    {
    case FLATPAK_FILESYSTEM_MODE_READ_ONLY:
      g_string_append (s, ":ro");
      break;

    case FLATPAK_FILESYSTEM_MODE_CREATE:
      g_string_append (s, ":create");
      break;

    case FLATPAK_FILESYSTEM_MODE_READ_WRITE:
      break;

    case FLATPAK_FILESYSTEM_MODE_NONE:
      g_string_insert_c (s, 0, '!');
      break;

    default:
      g_warning ("Unexpected filesystem mode %d", mode);
      break;
    }

  return g_string_free (g_steal_pointer (&s), FALSE);
}

static char *
parse_filesystem_flags (const char            *filesystem,
                        FlatpakFilesystemMode *mode_out)
{
  g_autoptr(GString) s = g_string_new ("");
  const char *p, *suffix;
  FlatpakFilesystemMode mode;

  p = filesystem;
  while (*p != 0 && *p != ':')
    {
      if (*p == '\\')
        {
          p++;
          if (*p != 0)
            g_string_append_c (s, *p++);
        }
      else
        g_string_append_c (s, *p++);
    }

  mode = FLATPAK_FILESYSTEM_MODE_READ_WRITE;

  if (*p == ':')
    {
      suffix = p + 1;

      if (strcmp (suffix, "ro") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_READ_ONLY;
      else if (strcmp (suffix, "rw") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_READ_WRITE;
      else if (strcmp (suffix, "create") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_CREATE;
      else if (*suffix != 0)
        g_warning ("Unexpected filesystem suffix %s, ignoring", suffix);
    }

  if (mode_out)
    *mode_out = mode;

  return g_string_free (g_steal_pointer (&s), FALSE);
}

gboolean
flatpak_context_parse_filesystem (const char             *filesystem_and_mode,
                                  char                  **filesystem_out,
                                  FlatpakFilesystemMode  *mode_out,
                                  GError                **error)
{
  g_autofree char *filesystem = parse_filesystem_flags (filesystem_and_mode, mode_out);
  char *slash;

  slash = strchr (filesystem, '/');

  /* Forbid /../ in paths */
  if (slash != NULL)
    {
      if (g_str_has_prefix (slash + 1, "../") ||
          g_str_has_suffix (slash + 1, "/..") ||
          strstr (slash + 1, "/../") != NULL)
        {
          g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                       _("Filesystem location \"%s\" contains \"..\""),
                       filesystem);
          return FALSE;
        }

      /* Convert "//" and "/./" to "/" */
      for (; slash != NULL; slash = strchr (slash + 1, '/'))
        {
          while (TRUE)
            {
              if (slash[1] == '/')
                memmove (slash + 1, slash + 2, strlen (slash + 2) + 1);
              else if (slash[1] == '.' && slash[2] == '/')
                memmove (slash + 1, slash + 3, strlen (slash + 3) + 1);
              else
                break;
            }
        }

      /* Eliminate trailing "/." or "/". */
      while (TRUE)
        {
          slash = strrchr (filesystem, '/');

          if (slash != NULL &&
              ((slash != filesystem && slash[1] == '\0') ||
               (slash[1] == '.' && slash[2] == '\0')))
            *slash = '\0';
          else
            break;
        }

      if (filesystem[0] == '/' && filesystem[1] == '\0')
        {
          /* We don't allow --filesystem=/ as equivalent to host, because
           * it doesn't do what you'd think: --filesystem=host mounts some
           * host directories in /run/host, not in the root. */
          g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                       _("--filesystem=/ is not available, "
                         "use --filesystem=host for a similar result"));
          return FALSE;
        }
    }

  if (g_strv_contains (flatpak_context_special_filesystems, filesystem) ||
      get_xdg_user_dir_from_string (filesystem, NULL, NULL, NULL) ||
      g_str_has_prefix (filesystem, "~/") ||
      g_str_has_prefix (filesystem, "/"))
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_steal_pointer (&filesystem);

      return TRUE;
    }

  if (strcmp (filesystem, "~") == 0)
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_strdup ("home");

      return TRUE;
    }

  if (g_str_has_prefix (filesystem, "home/"))
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_strconcat ("~/", filesystem + 5, NULL);

      return TRUE;
    }

  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Unknown filesystem location %s, valid locations are: host, host-os, host-etc, home, xdg-*[/…], ~/dir, /dir"), filesystem);
  return FALSE;
}

static void
flatpak_context_take_filesystem (FlatpakContext        *context,
                                 char                  *fs,
                                 FlatpakFilesystemMode  mode)
{
  g_hash_table_insert (context->filesystems, fs, GINT_TO_POINTER (mode));
}

void
flatpak_context_merge (FlatpakContext *context,
                       FlatpakContext *other)
{
  GHashTableIter iter;
  gpointer key, value;

  context->shares &= ~other->shares_valid;
  context->shares |= other->shares;
  context->shares_valid |= other->shares_valid;
  context->sockets &= ~other->sockets_valid;
  context->sockets |= other->sockets;
  context->sockets_valid |= other->sockets_valid;
  context->devices &= ~other->devices_valid;
  context->devices |= other->devices;
  context->devices_valid |= other->devices_valid;
  context->features &= ~other->features_valid;
  context->features |= other->features;
  context->features_valid |= other->features_valid;

  g_hash_table_iter_init (&iter, other->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->env_vars, g_strdup (key), g_strdup (value));

  g_hash_table_iter_init (&iter, other->persistent);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->persistent, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->filesystems, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->session_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->system_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->system_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->generic_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char **policy_values = (const char **) value;
      int i;

      for (i = 0; policy_values[i] != NULL; i++)
        flatpak_context_apply_generic_policy (context, (char *) key, policy_values[i]);
    }
}

static gboolean
option_share_cb (const gchar *option_name,
                 const gchar *value,
                 gpointer     data,
                 GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextShares share;

  share = flatpak_context_share_from_string (value, error);
  if (share == 0)
    return FALSE;

  flatpak_context_add_shares (context, share);

  return TRUE;
}

static gboolean
option_unshare_cb (const gchar *option_name,
                   const gchar *value,
                   gpointer     data,
                   GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextShares share;

  share = flatpak_context_share_from_string (value, error);
  if (share == 0)
    return FALSE;

  flatpak_context_remove_shares (context, share);

  return TRUE;
}

static gboolean
option_socket_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextSockets socket;

  socket = flatpak_context_socket_from_string (value, error);
  if (socket == 0)
    return FALSE;

  if (socket == FLATPAK_CONTEXT_SOCKET_FALLBACK_X11)
    socket |= FLATPAK_CONTEXT_SOCKET_X11;

  flatpak_context_add_sockets (context, socket);

  return TRUE;
}

static gboolean
option_nosocket_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextSockets socket;

  socket = flatpak_context_socket_from_string (value, error);
  if (socket == 0)
    return FALSE;

  if (socket == FLATPAK_CONTEXT_SOCKET_FALLBACK_X11)
    socket |= FLATPAK_CONTEXT_SOCKET_X11;

  flatpak_context_remove_sockets (context, socket);

  return TRUE;
}

static gboolean
option_device_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextDevices device;

  device = flatpak_context_device_from_string (value, error);
  if (device == 0)
    return FALSE;

  flatpak_context_add_devices (context, device);

  return TRUE;
}

static gboolean
option_nodevice_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextDevices device;

  device = flatpak_context_device_from_string (value, error);
  if (device == 0)
    return FALSE;

  flatpak_context_remove_devices (context, device);

  return TRUE;
}

static gboolean
option_allow_cb (const gchar *option_name,
                 const gchar *value,
                 gpointer     data,
                 GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextFeatures feature;

  feature = flatpak_context_feature_from_string (value, error);
  if (feature == 0)
    return FALSE;

  flatpak_context_add_features (context, feature);

  return TRUE;
}

static gboolean
option_disallow_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextFeatures feature;

  feature = flatpak_context_feature_from_string (value, error);
  if (feature == 0)
    return FALSE;

  flatpak_context_remove_features (context, feature);

  return TRUE;
}

static gboolean
option_filesystem_cb (const gchar *option_name,
                      const gchar *value,
                      gpointer     data,
                      GError     **error)
{
  FlatpakContext *context = data;
  g_autofree char *fs = NULL;
  FlatpakFilesystemMode mode;

  if (!flatpak_context_parse_filesystem (value, &fs, &mode, error))
    return FALSE;

  flatpak_context_take_filesystem (context, g_steal_pointer (&fs), mode);
  return TRUE;
}

static gboolean
option_nofilesystem_cb (const gchar *option_name,
                        const gchar *value,
                        gpointer     data,
                        GError     **error)
{
  FlatpakContext *context = data;
  g_autofree char *fs = NULL;
  FlatpakFilesystemMode mode;

  if (!flatpak_context_parse_filesystem (value, &fs, &mode, error))
    return FALSE;

  flatpak_context_take_filesystem (context, g_steal_pointer (&fs),
                                   FLATPAK_FILESYSTEM_MODE_NONE);
  return TRUE;
}

static gboolean
option_env_cb (const gchar *option_name,
               const gchar *value,
               gpointer     data,
               GError     **error)
{
  FlatpakContext *context = data;
  g_auto(GStrv) split = g_strsplit (value, "=", 2);

  if (split == NULL || split[0] == NULL || split[0][0] == 0 || split[1] == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Invalid env format %s"), value);
      return FALSE;
    }

  flatpak_context_set_env_var (context, split[0], split[1]);
  return TRUE;
}

gboolean
flatpak_context_parse_env_block (FlatpakContext *context,
                                 const char *data,
                                 gsize length,
                                 GError **error)
{
  const char *p = data;
  gsize remaining = length;

  /* env_block might not be \0-terminated */
  while (remaining > 0)
    {
      size_t len = strnlen (p, remaining);
      const char *equals;
      g_autofree char *env_var = NULL;
      g_autofree char *env_value = NULL;

      g_assert (len <= remaining);

      equals = memchr (p, '=', len);

      if (equals == NULL || equals == p)
        return glnx_throw (error,
                           "Environment variable must be given in the form VARIABLE=VALUE, not %.*s", (int) len, p);

      env_var = g_strndup (p, equals - p);
      env_value = g_strndup (equals + 1, len - (equals - p) - 1);
      flatpak_context_set_env_var (context, env_var, env_value);
      p += len;
      remaining -= len;

      if (remaining > 0)
        {
          g_assert (*p == '\0');
          p += 1;
          remaining -= 1;
        }
    }

  return TRUE;
}

gboolean
flatpak_context_parse_env_fd (FlatpakContext *context,
                              int fd,
                              GError **error)
{
  g_autoptr(GBytes) env_block = NULL;
  const char *data;
  gsize len;

  env_block = glnx_fd_readall_bytes (fd, NULL, error);

  if (env_block == NULL)
    return FALSE;

  data = g_bytes_get_data (env_block, &len);
  return flatpak_context_parse_env_block (context, data, len, error);
}

static gboolean
option_env_fd_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  guint64 fd;
  gchar *endptr;
  gboolean ret;

  fd = g_ascii_strtoull (value, &endptr, 10);

  if (endptr == NULL || *endptr != '\0' || fd > G_MAXINT)
    return glnx_throw (error, "Not a valid file descriptor: %s", value);

  ret = flatpak_context_parse_env_fd (context, (int) fd, error);

  if (fd >= 3)
    close (fd);

  return ret;
}

static gboolean
option_unset_env_cb (const gchar *option_name,
                     const gchar *value,
                     gpointer     data,
                     GError     **error)
{
  FlatpakContext *context = data;

  if (strchr (value, '=') != NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Environment variable name must not contain '=': %s"), value);
      return FALSE;
    }

  flatpak_context_set_env_var (context, value, NULL);
  return TRUE;
}

static gboolean
option_own_name_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_OWN);
  return TRUE;
}

static gboolean
option_talk_name_cb (const gchar *option_name,
                     const gchar *value,
                     gpointer     data,
                     GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_TALK);
  return TRUE;
}

static gboolean
option_no_talk_name_cb (const gchar *option_name,
                        const gchar *value,
                        gpointer     data,
                        GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_NONE);
  return TRUE;
}

static gboolean
option_system_own_name_cb (const gchar *option_name,
                           const gchar *value,
                           gpointer     data,
                           GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_OWN);
  return TRUE;
}

static gboolean
option_system_talk_name_cb (const gchar *option_name,
                            const gchar *value,
                            gpointer     data,
                            GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_TALK);
  return TRUE;
}

static gboolean
option_system_no_talk_name_cb (const gchar *option_name,
                               const gchar *value,
                               gpointer     data,
                               GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_NONE);
  return TRUE;
}

static gboolean
option_add_generic_policy_cb (const gchar *option_name,
                              const gchar *value,
                              gpointer     data,
                              GError     **error)
{
  FlatpakContext *context = data;
  char *t;
  g_autofree char *key = NULL;
  const char *policy_value;

  t = strchr (value, '=');
  if (t == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }
  policy_value = t + 1;
  key = g_strndup (value, t - value);
  if (strchr (key, '.') == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }

  if (policy_value[0] == '!')
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy values can't start with \"!\""));
      return FALSE;
    }

  flatpak_context_apply_generic_policy (context, key, policy_value);

  return TRUE;
}

static gboolean
option_remove_generic_policy_cb (const gchar *option_name,
                                 const gchar *value,
                                 gpointer     data,
                                 GError     **error)
{
  FlatpakContext *context = data;
  char *t;
  g_autofree char *key = NULL;
  const char *policy_value;
  g_autofree char *extended_value = NULL;

  t = strchr (value, '=');
  if (t == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }
  policy_value = t + 1;
  key = g_strndup (value, t - value);
  if (strchr (key, '.') == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }

  if (policy_value[0] == '!')
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy values can't start with \"!\""));
      return FALSE;
    }

  extended_value = g_strconcat ("!", policy_value, NULL);

  flatpak_context_apply_generic_policy (context, key, extended_value);

  return TRUE;
}

static gboolean
option_persist_cb (const gchar *option_name,
                   const gchar *value,
                   gpointer     data,
                   GError     **error)
{
  FlatpakContext *context = data;

  flatpak_context_set_persistent (context, value);
  return TRUE;
}

static gboolean option_no_desktop_deprecated;

static GOptionEntry context_options[] = {
  { "share", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_share_cb, N_("Share with host"), N_("SHARE") },
  { "unshare", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_unshare_cb, N_("Unshare with host"), N_("SHARE") },
  { "socket", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_socket_cb, N_("Expose socket to app"), N_("SOCKET") },
  { "nosocket", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_nosocket_cb, N_("Don't expose socket to app"), N_("SOCKET") },
  { "device", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_device_cb, N_("Expose device to app"), N_("DEVICE") },
  { "nodevice", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_nodevice_cb, N_("Don't expose device to app"), N_("DEVICE") },
  { "allow", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_allow_cb, N_("Allow feature"), N_("FEATURE") },
  { "disallow", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_disallow_cb, N_("Don't allow feature"), N_("FEATURE") },
  { "filesystem", 0, G_OPTION_FLAG_IN_MAIN | G_OPTION_FLAG_FILENAME, G_OPTION_ARG_CALLBACK, &option_filesystem_cb, N_("Expose filesystem to app (:ro for read-only)"), N_("FILESYSTEM[:ro]") },
  { "nofilesystem", 0, G_OPTION_FLAG_IN_MAIN | G_OPTION_FLAG_FILENAME, G_OPTION_ARG_CALLBACK, &option_nofilesystem_cb, N_("Don't expose filesystem to app"), N_("FILESYSTEM") },
  { "env", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_env_cb, N_("Set environment variable"), N_("VAR=VALUE") },
  { "env-fd", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_env_fd_cb, N_("Read environment variables in env -0 format from FD"), N_("FD") },
  { "unset-env", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_unset_env_cb, N_("Remove variable from environment"), N_("VAR") },
  { "own-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_own_name_cb, N_("Allow app to own name on the session bus"), N_("DBUS_NAME") },
  { "talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_talk_name_cb, N_("Allow app to talk to name on the session bus"), N_("DBUS_NAME") },
  { "no-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_no_talk_name_cb, N_("Don't allow app to talk to name on the session bus"), N_("DBUS_NAME") },
  { "system-own-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_own_name_cb, N_("Allow app to own name on the system bus"), N_("DBUS_NAME") },
  { "system-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_talk_name_cb, N_("Allow app to talk to name on the system bus"), N_("DBUS_NAME") },
  { "system-no-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_no_talk_name_cb, N_("Don't allow app to talk to name on the system bus"), N_("DBUS_NAME") },
  { "add-policy", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_add_generic_policy_cb, N_("Add generic policy option"), N_("SUBSYSTEM.KEY=VALUE") },
  { "remove-policy", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_remove_generic_policy_cb, N_("Remove generic policy option"), N_("SUBSYSTEM.KEY=VALUE") },
  { "persist", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_persist_cb, N_("Persist home directory subpath"), N_("FILENAME") },
  /* This is not needed/used anymore, so hidden, but we accept it for backwards compat */
  { "no-desktop", 0, G_OPTION_FLAG_IN_MAIN |  G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_NONE, &option_no_desktop_deprecated, N_("Don't require a running session (no cgroups creation)"), NULL },
  { NULL }
};

GOptionEntry *
flatpak_context_get_option_entries (void)
{
  return context_options;
}

GOptionGroup  *
flatpak_context_get_options (FlatpakContext *context)
{
  GOptionGroup *group;

  group = g_option_group_new ("environment",
                              "Runtime Environment",
                              "Runtime Environment",
                              context,
                              NULL);
  g_option_group_set_translation_domain (group, GETTEXT_PACKAGE);

  g_option_group_add_entries (group, context_options);

  return group;
}

static const char *
parse_negated (const char *option, gboolean *negated)
{
  if (option[0] == '!')
    {
      option++;
      *negated = TRUE;
    }
  else
    {
      *negated = FALSE;
    }
  return option;
}

/*
 * Merge the FLATPAK_METADATA_GROUP_CONTEXT,
 * FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
 * FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY and
 * FLATPAK_METADATA_GROUP_ENVIRONMENT groups, and all groups starting
 * with FLATPAK_METADATA_GROUP_PREFIX_POLICY, from metakey into context.
 *
 * This is a merge, not a replace!
 */
gboolean
flatpak_context_load_metadata (FlatpakContext *context,
                               GKeyFile       *metakey,
                               GError        **error)
{
  gboolean remove;
  g_auto(GStrv) groups = NULL;
  gsize i;

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_SHARED, NULL))
    {
      g_auto(GStrv) shares = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                         FLATPAK_METADATA_KEY_SHARED, NULL, error);
      if (shares == NULL)
        return FALSE;

      for (i = 0; shares[i] != NULL; i++)
        {
          FlatpakContextShares share;

          share = flatpak_context_share_from_string (parse_negated (shares[i], &remove), NULL);
          if (share == 0)
            g_debug ("Unknown share type %s", shares[i]);
          else
            {
              if (remove)
                flatpak_context_remove_shares (context, share);
              else
                flatpak_context_add_shares (context, share);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_SOCKETS, NULL))
    {
      g_auto(GStrv) sockets = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                          FLATPAK_METADATA_KEY_SOCKETS, NULL, error);
      if (sockets == NULL)
        return FALSE;

      for (i = 0; sockets[i] != NULL; i++)
        {
          FlatpakContextSockets socket = flatpak_context_socket_from_string (parse_negated (sockets[i], &remove), NULL);
          if (socket == 0)
            g_debug ("Unknown socket type %s", sockets[i]);
          else
            {
              if (remove)
                flatpak_context_remove_sockets (context, socket);
              else
                flatpak_context_add_sockets (context, socket);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_DEVICES, NULL))
    {
      g_auto(GStrv) devices = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                          FLATPAK_METADATA_KEY_DEVICES, NULL, error);
      if (devices == NULL)
        return FALSE;


      for (i = 0; devices[i] != NULL; i++)
        {
          FlatpakContextDevices device = flatpak_context_device_from_string (parse_negated (devices[i], &remove), NULL);
          if (device == 0)
            g_debug ("Unknown device type %s", devices[i]);
          else
            {
              if (remove)
                flatpak_context_remove_devices (context, device);
              else
                flatpak_context_add_devices (context, device);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_FEATURES, NULL))
    {
      g_auto(GStrv) features = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                           FLATPAK_METADATA_KEY_FEATURES, NULL, error);
      if (features == NULL)
        return FALSE;


      for (i = 0; features[i] != NULL; i++)
        {
          FlatpakContextFeatures feature = flatpak_context_feature_from_string (parse_negated (features[i], &remove), NULL);
          if (feature == 0)
            g_debug ("Unknown feature type %s", features[i]);
          else
            {
              if (remove)
                flatpak_context_remove_features (context, feature);
              else
                flatpak_context_add_features (context, feature);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_FILESYSTEMS, NULL))
    {
      g_auto(GStrv) filesystems = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                              FLATPAK_METADATA_KEY_FILESYSTEMS, NULL, error);
      if (filesystems == NULL)
        return FALSE;

      for (i = 0; filesystems[i] != NULL; i++)
        {
          const char *fs = parse_negated (filesystems[i], &remove);
          g_autofree char *filesystem = NULL;
          FlatpakFilesystemMode mode;

          if (!flatpak_context_parse_filesystem (fs, &filesystem, &mode, NULL))
            g_debug ("Unknown filesystem type %s", filesystems[i]);
          else
            {
              if (remove)
                flatpak_context_take_filesystem (context, g_steal_pointer (&filesystem),
                                                 FLATPAK_FILESYSTEM_MODE_NONE);
              else
                flatpak_context_take_filesystem (context, g_steal_pointer (&filesystem), mode);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_PERSISTENT, NULL))
    {
      g_auto(GStrv) persistent = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                             FLATPAK_METADATA_KEY_PERSISTENT, NULL, error);
      if (persistent == NULL)
        return FALSE;

      for (i = 0; persistent[i] != NULL; i++)
        flatpak_context_set_persistent (context, persistent[i]);
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, key, NULL);
          FlatpakPolicy policy;

          if (!flatpak_verify_dbus_name (key, error))
            return FALSE;

          policy = flatpak_policy_from_string (value, NULL);
          if ((int) policy != -1)
            flatpak_context_set_session_bus_policy (context, key, policy);
        }
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, key, NULL);
          FlatpakPolicy policy;

          if (!flatpak_verify_dbus_name (key, error))
            return FALSE;

          policy = flatpak_policy_from_string (value, NULL);
          if ((int) policy != -1)
            flatpak_context_set_system_bus_policy (context, key, policy);
        }
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, key, NULL);

          flatpak_context_set_env_var (context, key, value);
        }
    }

  /* unset-environment is higher precedence than Environment, so that
   * we can put unset keys in both places. Old versions of Flatpak will
   * interpret the empty string as unset; new versions will obey
   * unset-environment. */
  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT, NULL))
    {
      g_auto(GStrv) vars = NULL;
      gsize vars_count;

      vars = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                         FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT,
                                         &vars_count, error);

      if (vars == NULL)
        return FALSE;

      for (i = 0; i < vars_count; i++)
        {
          const char *var = vars[i];

          flatpak_context_set_env_var (context, var, NULL);
        }
    }

  groups = g_key_file_get_groups (metakey, NULL);
  for (i = 0; groups[i] != NULL; i++)
    {
      const char *group = groups[i];
      const char *subsystem;
      int j;

      if (g_str_has_prefix (group, FLATPAK_METADATA_GROUP_PREFIX_POLICY))
        {
          g_auto(GStrv) keys = NULL;
          subsystem = group + strlen (FLATPAK_METADATA_GROUP_PREFIX_POLICY);
          keys = g_key_file_get_keys (metakey, group, NULL, NULL);
          for (j = 0; keys != NULL && keys[j] != NULL; j++)
            {
              const char *key = keys[j];
              g_autofree char *policy_key = g_strdup_printf ("%s.%s", subsystem, key);
              g_auto(GStrv) values = NULL;
              int k;

              values = g_key_file_get_string_list (metakey, group, key, NULL, NULL);
              for (k = 0; values != NULL && values[k] != NULL; k++)
                flatpak_context_apply_generic_policy (context, policy_key,
                                                      values[k]);
            }
        }
    }

  return TRUE;
}

/*
 * Save the FLATPAK_METADATA_GROUP_CONTEXT,
 * FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
 * FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY and
 * FLATPAK_METADATA_GROUP_ENVIRONMENT groups, and all groups starting
 * with FLATPAK_METADATA_GROUP_PREFIX_POLICY, into metakey
 */
void
flatpak_context_save_metadata (FlatpakContext *context,
                               gboolean        flatten,
                               GKeyFile       *metakey)
{
  g_auto(GStrv) shared = NULL;
  g_auto(GStrv) sockets = NULL;
  g_auto(GStrv) devices = NULL;
  g_auto(GStrv) features = NULL;
  g_autoptr(GPtrArray) unset_env = NULL;
  GHashTableIter iter;
  gpointer key, value;
  FlatpakContextShares shares_mask = context->shares;
  FlatpakContextShares shares_valid = context->shares_valid;
  FlatpakContextSockets sockets_mask = context->sockets;
  FlatpakContextSockets sockets_valid = context->sockets_valid;
  FlatpakContextDevices devices_mask = context->devices;
  FlatpakContextDevices devices_valid = context->devices_valid;
  FlatpakContextFeatures features_mask = context->features;
  FlatpakContextFeatures features_valid = context->features_valid;
  g_auto(GStrv) groups = NULL;
  int i;

  if (flatten)
    {
      /* A flattened format means we don't expect this to be merged on top of
         another context. In that case we never need to negate any flags.
         We calculate this by removing the zero parts of the mask from the valid set.
       */
      /* First we make sure only the valid parts of the mask are set, in case we
         got some leftover */
      shares_mask &= shares_valid;
      sockets_mask &= sockets_valid;
      devices_mask &= devices_valid;
      features_mask &= features_valid;

      /* Then just set the valid set to be the mask set */
      shares_valid = shares_mask;
      sockets_valid = sockets_mask;
      devices_valid = devices_mask;
      features_valid = features_mask;
    }

  shared = flatpak_context_shared_to_string (shares_mask, shares_valid);
  sockets = flatpak_context_sockets_to_string (sockets_mask, sockets_valid);
  devices = flatpak_context_devices_to_string (devices_mask, devices_valid);
  features = flatpak_context_features_to_string (features_mask, features_valid);

  if (shared[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_SHARED,
                                  (const char * const *) shared, g_strv_length (shared));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_SHARED,
                             NULL);
    }

  if (sockets[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_SOCKETS,
                                  (const char * const *) sockets, g_strv_length (sockets));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_SOCKETS,
                             NULL);
    }

  if (devices[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_DEVICES,
                                  (const char * const *) devices, g_strv_length (devices));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_DEVICES,
                             NULL);
    }

  if (features[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_FEATURES,
                                  (const char * const *) features, g_strv_length (features));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_FEATURES,
                             NULL);
    }

  if (g_hash_table_size (context->filesystems) > 0)
    {
      g_autoptr(GPtrArray) array = g_ptr_array_new_with_free_func (g_free);

      g_hash_table_iter_init (&iter, context->filesystems);
      while (g_hash_table_iter_next (&iter, &key, &value))
        {
          FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

          g_ptr_array_add (array, unparse_filesystem_flags (key, mode));
        }

      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_FILESYSTEMS,
                                  (const char * const *) array->pdata, array->len);
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_FILESYSTEMS,
                             NULL);
    }

  if (g_hash_table_size (context->persistent) > 0)
    {
      g_autofree char **keys = (char **) g_hash_table_get_keys_as_array (context->persistent, NULL);

      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_PERSISTENT,
                                  (const char * const *) keys, g_strv_length (keys));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_PERSISTENT,
                             NULL);
    }

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, NULL);
  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (flatten && (policy == 0))
        continue;

      g_key_file_set_string (metakey,
                             FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
                             (char *) key, flatpak_policy_to_string (policy));
    }

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, NULL);
  g_hash_table_iter_init (&iter, context->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (flatten && (policy == 0))
        continue;

      g_key_file_set_string (metakey,
                             FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY,
                             (char *) key, flatpak_policy_to_string (policy));
    }

  /* Elements are borrowed from context->env_vars */
  unset_env = g_ptr_array_new ();

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, NULL);
  g_hash_table_iter_init (&iter, context->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      if (value != NULL)
        {
          g_key_file_set_string (metakey,
                                 FLATPAK_METADATA_GROUP_ENVIRONMENT,
                                 (char *) key, (char *) value);
        }
      else
        {
          /* In older versions of Flatpak, [Environment] FOO=
           * was interpreted as unsetting - so let's do both. */
          g_key_file_set_string (metakey,
                                 FLATPAK_METADATA_GROUP_ENVIRONMENT,
                                 (char *) key, "");
          g_ptr_array_add (unset_env, key);
        }
    }

  if (unset_env->len > 0)
    {
      g_ptr_array_add (unset_env, NULL);
      g_key_file_set_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT,
                                  (const char * const *) unset_env->pdata,
                                  unset_env->len - 1);
    }
  else
    {
      g_key_file_remove_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT, NULL);
    }

  groups = g_key_file_get_groups (metakey, NULL);
  for (i = 0; groups[i] != NULL; i++)
    {
      const char *group = groups[i];
      if (g_str_has_prefix (group, FLATPAK_METADATA_GROUP_PREFIX_POLICY))
        g_key_file_remove_group (metakey, group, NULL);
    }

  g_hash_table_iter_init (&iter, context->generic_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      g_auto(GStrv) parts = g_strsplit ((const char *) key, ".", 2);
      g_autofree char *group = NULL;
      g_assert (parts[1] != NULL);
      const char **policy_values = (const char **) value;
      g_autoptr(GPtrArray) new = g_ptr_array_new ();

      for (i = 0; policy_values[i] != NULL; i++)
        {
          const char *policy_value = policy_values[i];

          if (!flatten || policy_value[0] != '!')
            g_ptr_array_add (new, (char *) policy_value);
        }

      if (new->len > 0)
        {
          group = g_strconcat (FLATPAK_METADATA_GROUP_PREFIX_POLICY,
                               parts[0], NULL);
          g_key_file_set_string_list (metakey, group, parts[1],
                                      (const char * const *) new->pdata,
                                      new->len);
        }
    }
}

void
flatpak_context_allow_host_fs (FlatpakContext *context)
{
  flatpak_context_take_filesystem (context, g_strdup ("host"), FLATPAK_FILESYSTEM_MODE_READ_WRITE);
}

gboolean
flatpak_context_get_needs_session_bus_proxy (FlatpakContext *context)
{
  return g_hash_table_size (context->session_bus_policy) > 0;
}

gboolean
flatpak_context_get_needs_system_bus_proxy (FlatpakContext *context)
{
  return g_hash_table_size (context->system_bus_policy) > 0;
}

static gboolean
adds_flags (guint32 old_flags, guint32 new_flags)
{
  return (new_flags & ~old_flags) != 0;
}

static gboolean
adds_bus_policy (GHashTable *old, GHashTable *new)
{
  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, name, gpointer, _new_policy)
    {
      int new_policy = GPOINTER_TO_INT (_new_policy);
      int old_policy = GPOINTER_TO_INT (g_hash_table_lookup (old, name));
      if (new_policy > old_policy)
        return TRUE;
    }

  return FALSE;
}

static gboolean
adds_generic_policy (GHashTable *old, GHashTable *new)
{
  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, key, GPtrArray *, new_values)
    {
      GPtrArray *old_values = g_hash_table_lookup (old, key);
      int i;

      if (new_values == NULL || new_values->len == 0)
        continue;

      if (old_values == NULL || old_values->len == 0)
        return TRUE;

      for (i = 0; i < new_values->len; i++)
        {
          const char *new_value = g_ptr_array_index (new_values, i);

          if (!flatpak_g_ptr_array_contains_string (old_values, new_value))
            return TRUE;
        }
    }

  return FALSE;
}

static gboolean
adds_filesystem_access (GHashTable *old, GHashTable *new)
{
  FlatpakFilesystemMode old_host_mode = GPOINTER_TO_INT (g_hash_table_lookup (old, "host"));

  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, location, gpointer, _new_mode)
    {
      FlatpakFilesystemMode new_mode = GPOINTER_TO_INT (_new_mode);
      FlatpakFilesystemMode old_mode = GPOINTER_TO_INT (g_hash_table_lookup (old, location));

      /* Allow more limited access to the same thing */
      if (new_mode <= old_mode)
        continue;

      /* Allow more limited access if we used to have access to everything */
     if (new_mode <= old_host_mode)
        continue;

     /* For the remainder we have to be pessimistic, for instance even
        if we have home access we can't allow adding access to ~/foo,
        because foo might be a symlink outside home which didn't work
        before but would work with an explicit access to that
        particular file. */

      return TRUE;
    }

  return FALSE;
}


gboolean
flatpak_context_adds_permissions (FlatpakContext *old,
                                  FlatpakContext *new)
{
  /* We allow upgrade to multiarch, that is really not a huge problem.
   * Similarly, having sensible semantics for /dev/shm is
   * not a security concern. */
  guint32 harmless_features = (FLATPAK_CONTEXT_FEATURE_MULTIARCH |
                               FLATPAK_CONTEXT_FEATURE_PER_APP_DEV_SHM);
  guint32 old_sockets;

  if (adds_flags (old->shares & old->shares_valid,
                  new->shares & new->shares_valid))
    return TRUE;

  old_sockets = old->sockets & old->sockets_valid;

  /* If we used to allow X11, also allow new fallback X11,
     as that is actually less permissions */
  if (old_sockets & FLATPAK_CONTEXT_SOCKET_X11)
    old_sockets |= FLATPAK_CONTEXT_SOCKET_FALLBACK_X11;

  if (adds_flags (old_sockets,
                  new->sockets & new->sockets_valid))
    return TRUE;

  if (adds_flags (old->devices & old->devices_valid,
                  new->devices & new->devices_valid))
    return TRUE;

  if (adds_flags ((old->features & old->features_valid) | harmless_features,
                  new->features & new->features_valid))
    return TRUE;

  if (adds_bus_policy (old->session_bus_policy, new->session_bus_policy))
    return TRUE;

  if (adds_bus_policy (old->system_bus_policy, new->system_bus_policy))
    return TRUE;

  if (adds_generic_policy (old->generic_policy, new->generic_policy))
    return TRUE;

  if (adds_filesystem_access (old->filesystems, new->filesystems))
    return TRUE;

  return FALSE;
}

gboolean
flatpak_context_allows_features (FlatpakContext        *context,
                                 FlatpakContextFeatures features)
{
  return (context->features & features) == features;
}

void
flatpak_context_to_args (FlatpakContext *context,
                         GPtrArray      *args)
{
  GHashTableIter iter;
  gpointer key, value;

  flatpak_context_shared_to_args (context->shares, context->shares_valid, args);
  flatpak_context_sockets_to_args (context->sockets, context->sockets_valid, args);
  flatpak_context_devices_to_args (context->devices, context->devices_valid, args);
  flatpak_context_features_to_args (context->features, context->features_valid, args);

  g_hash_table_iter_init (&iter, context->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      if (value != NULL)
        g_ptr_array_add (args, g_strdup_printf ("--env=%s=%s", (char *) key, (char *) value));
      else
        g_ptr_array_add (args, g_strdup_printf ("--unset-env=%s", (char *) key));
    }

  g_hash_table_iter_init (&iter, context->persistent);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_ptr_array_add (args, g_strdup_printf ("--persist=%s", (char *) key));

  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *name = key;
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      g_ptr_array_add (args, g_strdup_printf ("--%s-name=%s", flatpak_policy_to_string (policy), name));
    }

  g_hash_table_iter_init (&iter, context->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *name = key;
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      g_ptr_array_add (args, g_strdup_printf ("--system-%s-name=%s", flatpak_policy_to_string (policy), name));
    }

  g_hash_table_iter_init (&iter, context->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

      if (mode != FLATPAK_FILESYSTEM_MODE_NONE)
        {
          g_autofree char *fs = unparse_filesystem_flags (key, mode);
          g_ptr_array_add (args, g_strdup_printf ("--filesystem=%s", fs));
        }
      else
        g_ptr_array_add (args, g_strdup_printf ("--nofilesystem=%s", (char *) key));
    }
}

void
flatpak_context_add_bus_filters (FlatpakContext *context,
                                 const char     *app_id,
                                 gboolean        session_bus,
                                 gboolean        sandboxed,
                                 FlatpakBwrap   *bwrap)
{
  GHashTable *ht;
  GHashTableIter iter;
  gpointer key, value;

  flatpak_bwrap_add_arg (bwrap, "--filter");
  if (app_id && session_bus)
    {
      if (!sandboxed)
        {
          flatpak_bwrap_add_arg_printf (bwrap, "--own=%s.*", app_id);
          flatpak_bwrap_add_arg_printf (bwrap, "--own=org.mpris.MediaPlayer2.%s.*", app_id);
        }
      else
        flatpak_bwrap_add_arg_printf (bwrap, "--own=%s.Sandboxed.*", app_id);
    }

  if (session_bus)
    ht = context->session_bus_policy;
  else
    ht = context->system_bus_policy;

  g_hash_table_iter_init (&iter, ht);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (policy > 0)
        flatpak_bwrap_add_arg_printf (bwrap, "--%s=%s",
                                      flatpak_policy_to_string (policy),
                                      (char *) key);
    }
}

void
flatpak_context_reset_non_permissions (FlatpakContext *context)
{
  g_hash_table_remove_all (context->env_vars);
}

void
flatpak_context_reset_permissions (FlatpakContext *context)
{
  context->shares_valid = 0;
  context->sockets_valid = 0;
  context->devices_valid = 0;
  context->features_valid = 0;

  context->shares = 0;
  context->sockets = 0;
  context->devices = 0;
  context->features = 0;

  g_hash_table_remove_all (context->persistent);
  g_hash_table_remove_all (context->filesystems);
  g_hash_table_remove_all (context->session_bus_policy);
  g_hash_table_remove_all (context->system_bus_policy);
  g_hash_table_remove_all (context->generic_policy);
}

void
flatpak_context_make_sandboxed (FlatpakContext *context)
{
  /* We drop almost everything from the app permission, except
   * multiarch which is inherited, to make sure app code keeps
   * running. */
  context->shares_valid &= 0;
  context->sockets_valid &= 0;
  context->devices_valid &= 0;
  context->features_valid &= FLATPAK_CONTEXT_FEATURE_MULTIARCH;

  context->shares &= context->shares_valid;
  context->sockets &= context->sockets_valid;
  context->devices &= context->devices_valid;
  context->features &= context->features_valid;

  g_hash_table_remove_all (context->persistent);
  g_hash_table_remove_all (context->filesystems);
  g_hash_table_remove_all (context->session_bus_policy);
  g_hash_table_remove_all (context->system_bus_policy);
  g_hash_table_remove_all (context->generic_policy);
}

const char *dont_mount_in_root[] = {
  ".", "..", "lib", "lib32", "lib64", "bin", "sbin", "usr", "boot", "root",
  "tmp", "etc", "app", "run", "proc", "sys", "dev", "var", NULL
};

static void
flatpak_context_export (FlatpakContext *context,
                        FlatpakExports *exports,
                        GFile          *app_id_dir,
                        GPtrArray       *extra_app_id_dirs,
                        gboolean        do_create,
                        gchar         **xdg_dirs_conf_out,
                        gboolean       *home_access_out)
{
  gboolean home_access = FALSE;
  g_autoptr(GString) xdg_dirs_conf = NULL;
  FlatpakFilesystemMode fs_mode, os_mode, etc_mode, home_mode;
  GHashTableIter iter;
  gpointer key, value;

  if (xdg_dirs_conf_out != NULL)
    xdg_dirs_conf = g_string_new ("");

  fs_mode = GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host"));
  if (fs_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    {
      DIR *dir;
      struct dirent *dirent;

      g_debug ("Allowing host-fs access");
      home_access = TRUE;

      /* Bind mount most dirs in / into the new root */
      dir = opendir ("/");
      if (dir != NULL)
        {
          while ((dirent = readdir (dir)))
            {
              g_autofree char *path = NULL;

              if (g_strv_contains (dont_mount_in_root, dirent->d_name))
                continue;

              path = g_build_filename ("/", dirent->d_name, NULL);
              flatpak_exports_add_path_expose (exports, fs_mode, path);
            }
          closedir (dir);
        }
      flatpak_exports_add_path_expose (exports, fs_mode, "/run/media");
    }

  os_mode = MAX (GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host-os")),
                   fs_mode);

  if (os_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    flatpak_exports_add_host_os_expose (exports, os_mode);

  etc_mode = MAX (GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host-etc")),
                   fs_mode);

  if (etc_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    flatpak_exports_add_host_etc_expose (exports, etc_mode);

  home_mode = GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "home"));
  if (home_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    {
      g_debug ("Allowing homedir access");
      home_access = TRUE;

      flatpak_exports_add_path_expose (exports, MAX (home_mode, fs_mode), g_get_home_dir ());
    }

  g_hash_table_iter_init (&iter, context->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *filesystem = key;
      FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

      if (g_strv_contains (flatpak_context_special_filesystems, filesystem))
        continue;

      if (g_str_has_prefix (filesystem, "xdg-"))
        {
          const char *path, *rest = NULL;
          const char *config_key = NULL;
          g_autofree char *subpath = NULL;

          if (!get_xdg_user_dir_from_string (filesystem, &config_key, &rest, &path))
            {
              g_warning ("Unsupported xdg dir %s", filesystem);
              continue;
            }

          if (path == NULL)
            continue; /* Unconfigured, ignore */

          if (strcmp (path, g_get_home_dir ()) == 0)
            {
              /* xdg-user-dirs sets disabled dirs to $HOME, and its in general not a good
                 idea to set full access to $HOME other than explicitly, so we ignore
                 these */
              g_debug ("Xdg dir %s is $HOME (i.e. disabled), ignoring", filesystem);
              continue;
            }

          subpath = g_build_filename (path, rest, NULL);

          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (subpath, 0755);

          if (g_file_test (subpath, G_FILE_TEST_EXISTS))
            {
              if (config_key && xdg_dirs_conf)
                g_string_append_printf (xdg_dirs_conf, "%s=\"%s\"\n",
                                        config_key, path);

              flatpak_exports_add_path_expose_or_hide (exports, mode, subpath);
            }
        }
      else if (g_str_has_prefix (filesystem, "~/"))
        {
          g_autofree char *path = NULL;

          path = g_build_filename (g_get_home_dir (), filesystem + 2, NULL);

          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (path, 0755);

          if (g_file_test (path, G_FILE_TEST_EXISTS))
            flatpak_exports_add_path_expose_or_hide (exports, mode, path);
        }
      else if (g_str_has_prefix (filesystem, "/"))
        {
          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (filesystem, 0755);

          if (g_file_test (filesystem, G_FILE_TEST_EXISTS))
            flatpak_exports_add_path_expose_or_hide (exports, mode, filesystem);
        }
      else
        {
          g_warning ("Unexpected filesystem arg %s", filesystem);
        }
    }

  if (app_id_dir)
    {
      g_autoptr(GFile) apps_dir = g_file_get_parent (app_id_dir);
      int i;
      /* Hide the .var/app dir by default (unless explicitly made visible) */
      flatpak_exports_add_path_tmpfs (exports, flatpak_file_get_path_cached (apps_dir));
      /* But let the app write to the per-app dir in it */
      flatpak_exports_add_path_expose (exports, FLATPAK_FILESYSTEM_MODE_READ_WRITE,
                                       flatpak_file_get_path_cached (app_id_dir));

      if (extra_app_id_dirs != NULL)
        {
          for (i = 0; i < extra_app_id_dirs->len; i++)
            {
              GFile *extra_app_id_dir = g_ptr_array_index (extra_app_id_dirs, i);
              flatpak_exports_add_path_expose (exports, FLATPAK_FILESYSTEM_MODE_READ_WRITE,
                                               flatpak_file_get_path_cached (extra_app_id_dir));
            }
        }
    }

  if (home_access_out != NULL)
    *home_access_out = home_access;

  if (xdg_dirs_conf_out != NULL)
    {
      g_assert (xdg_dirs_conf != NULL);
      *xdg_dirs_conf_out = g_string_free (g_steal_pointer (&xdg_dirs_conf), FALSE);
    }
}

FlatpakExports *
flatpak_context_get_exports (FlatpakContext *context,
                             const char     *app_id)
{
  g_autoptr(GFile) app_id_dir = flatpak_get_data_dir (app_id);

  return flatpak_context_get_exports_full (context,
                                           app_id_dir, NULL,
                                           FALSE, FALSE, NULL, NULL);
}

FlatpakRunFlags
flatpak_context_get_run_flags (FlatpakContext *context)
{
  FlatpakRunFlags flags = 0;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_DEVEL))
    flags |= FLATPAK_RUN_FLAG_DEVEL;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_MULTIARCH))
    flags |= FLATPAK_RUN_FLAG_MULTIARCH;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_BLUETOOTH))
    flags |= FLATPAK_RUN_FLAG_BLUETOOTH;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_CANBUS))
    flags |= FLATPAK_RUN_FLAG_CANBUS;

  return flags;
}

FlatpakExports *
flatpak_context_get_exports_full (FlatpakContext *context,
                                  GFile          *app_id_dir,
                                  GPtrArray      *extra_app_id_dirs,
                                  gboolean        do_create,
                                  gboolean        include_default_dirs,
                                  gchar         **xdg_dirs_conf_out,
                                  gboolean       *home_access_out)
{
  g_autoptr(FlatpakExports) exports = flatpak_exports_new ();

  flatpak_context_export (context, exports,
                          app_id_dir, extra_app_id_dirs,
                          do_create, xdg_dirs_conf_out, home_access_out);

  if (include_default_dirs)
    {
      g_autoptr(GFile) user_flatpak_dir = NULL;

      /* Hide the flatpak dir by default (unless explicitly made visible) */
      user_flatpak_dir = flatpak_get_user_base_dir_location ();
      flatpak_exports_add_path_tmpfs (exports, flatpak_file_get_path_cached (user_flatpak_dir));

      /* Ensure we always have a homedir */
      flatpak_exports_add_path_dir (exports, g_get_home_dir ());
    }

  return g_steal_pointer (&exports);
}

void
flatpak_context_append_bwrap_filesystem (FlatpakContext  *context,
                                         FlatpakBwrap    *bwrap,
                                         const char      *app_id,
                                         GFile           *app_id_dir,
                                         FlatpakExports  *exports,
                                         const char      *xdg_dirs_conf,
                                         gboolean         home_access)
{
  GHashTableIter iter;
  gpointer key, value;

  if (app_id_dir != NULL)
    flatpak_run_apply_env_appid (bwrap, app_id_dir);

  if (!home_access)
    {
      /* Enable persistent mapping only if no access to real home dir */

      g_hash_table_iter_init (&iter, context->persistent);
      while (g_hash_table_iter_next (&iter, &key, NULL))
        {
          const char *persist = key;
          g_autofree char *src = g_build_filename (g_get_home_dir (), ".var/app", app_id, persist, NULL);
          g_autofree char *dest = g_build_filename (g_get_home_dir (), persist, NULL);

          g_mkdir_with_parents (src, 0755);

          flatpak_bwrap_add_bind_arg (bwrap, "--bind", src, dest);
        }
    }

  if (app_id_dir != NULL)
    {
      g_autofree char *user_runtime_dir = flatpak_get_real_xdg_runtime_dir ();
      g_autofree char *run_user_app_dst = g_strdup_printf ("/run/flatpak/app/%s", app_id);
      g_autofree char *run_user_app_src = g_build_filename (user_runtime_dir, "app", app_id, NULL);

      if (glnx_shutil_mkdir_p_at (AT_FDCWD,
                                  run_user_app_src,
                                  0700,
                                  NULL,
                                  NULL))
        flatpak_bwrap_add_args (bwrap,
                                "--bind", run_user_app_src, run_user_app_dst,
                                NULL);

      /* Later, we'll make $XDG_RUNTIME_DIR/app a symlink to /run/flatpak/app */
      flatpak_bwrap_add_runtime_dir_member (bwrap, "app");
    }

  /* This actually outputs the args for the hide/expose operations
   * in the exports */
  flatpak_exports_append_bwrap_args (exports, bwrap);

  /* Special case subdirectories of the cache, config and data xdg
   * dirs.  If these are accessible explicitly, then we bind-mount
   * these in the app-id dir. This allows applications to explicitly
   * opt out of keeping some config/cache/data in the app-specific
   * directory.
   */
  if (app_id_dir)
    {
      g_hash_table_iter_init (&iter, context->filesystems);
      while (g_hash_table_iter_next (&iter, &key, &value))
        {
          const char *filesystem = key;
          FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);
          g_autofree char *xdg_path = NULL;
          const char *rest, *where;

          xdg_path = get_xdg_dir_from_string (filesystem, &rest, &where);

          if (xdg_path != NULL && *rest != 0 &&
              mode >= FLATPAK_FILESYSTEM_MODE_READ_ONLY)
            {
              g_autoptr(GFile) app_version = g_file_get_child (app_id_dir, where);
              g_autoptr(GFile) app_version_subdir = g_file_resolve_relative_path (app_version, rest);

              if (g_file_test (xdg_path, G_FILE_TEST_IS_DIR) ||
                  g_file_test (xdg_path, G_FILE_TEST_IS_REGULAR))
                {
                  g_autofree char *xdg_path_in_app = g_file_get_path (app_version_subdir);
                  flatpak_bwrap_add_bind_arg (bwrap,
                                              mode == FLATPAK_FILESYSTEM_MODE_READ_ONLY ? "--ro-bind" : "--bind",
                                              xdg_path, xdg_path_in_app);
                }
            }
        }
    }

  if (home_access && app_id_dir != NULL)
    {
      g_autofree char *src_path = g_build_filename (g_get_user_config_dir (),
                                                    "user-dirs.dirs",
                                                    NULL);
      g_autofree char *path = g_build_filename (flatpak_file_get_path_cached (app_id_dir),
                                                "config/user-dirs.dirs", NULL);
      if (g_file_test (src_path, G_FILE_TEST_EXISTS))
        flatpak_bwrap_add_bind_arg (bwrap, "--ro-bind", src_path, path);
    }
  else if (xdg_dirs_conf != NULL && xdg_dirs_conf[0] != '\0' && app_id_dir != NULL)
    {
      g_autofree char *path =
        g_build_filename (flatpak_file_get_path_cached (app_id_dir),
                          "config/user-dirs.dirs", NULL);

      flatpak_bwrap_add_args_data (bwrap, "xdg-config-dirs",
                                   xdg_dirs_conf, strlen (xdg_dirs_conf), path, NULL);
    }
}


Fixed version (ground truth):
/*
 * Copyright © 2014-2018 Red Hat, Inc
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *       Alexander Larsson <alexl@redhat.com>
 */

#include "config.h"

#include <string.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/personality.h>
#include <grp.h>
#include <unistd.h>
#include <gio/gunixfdlist.h>

#include <glib/gi18n-lib.h>

#include <gio/gio.h>
#include "libglnx/libglnx.h"

#include "flatpak-run-private.h"
#include "flatpak-proxy.h"
#include "flatpak-utils-private.h"
#include "flatpak-dir-private.h"
#include "flatpak-systemd-dbus-generated.h"
#include "flatpak-error.h"

/* Same order as enum */
const char *flatpak_context_shares[] = {
  "network",
  "ipc",
  NULL
};

/* Same order as enum */
const char *flatpak_context_sockets[] = {
  "x11",
  "wayland",
  "pulseaudio",
  "session-bus",
  "system-bus",
  "fallback-x11",
  "ssh-auth",
  "pcsc",
  "cups",
  NULL
};

const char *flatpak_context_devices[] = {
  "dri",
  "all",
  "kvm",
  "shm",
  NULL
};

const char *flatpak_context_features[] = {
  "devel",
  "multiarch",
  "bluetooth",
  "canbus",
  "per-app-dev-shm",
  NULL
};

const char *flatpak_context_special_filesystems[] = {
  "home",
  "host",
  "host-etc",
  "host-os",
  NULL
};

FlatpakContext *
flatpak_context_new (void)
{
  FlatpakContext *context;

  context = g_slice_new0 (FlatpakContext);
  context->env_vars = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
  context->persistent = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  /* filename or special filesystem name => FlatpakFilesystemMode */
  context->filesystems = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->session_bus_policy = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->system_bus_policy = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  context->generic_policy = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                   g_free, (GDestroyNotify) g_strfreev);

  return context;
}

void
flatpak_context_free (FlatpakContext *context)
{
  g_hash_table_destroy (context->env_vars);
  g_hash_table_destroy (context->persistent);
  g_hash_table_destroy (context->filesystems);
  g_hash_table_destroy (context->session_bus_policy);
  g_hash_table_destroy (context->system_bus_policy);
  g_hash_table_destroy (context->generic_policy);
  g_slice_free (FlatpakContext, context);
}

static guint32
flatpak_context_bitmask_from_string (const char *name, const char **names)
{
  guint32 i;

  for (i = 0; names[i] != NULL; i++)
    {
      if (strcmp (names[i], name) == 0)
        return 1 << i;
    }

  return 0;
}

static char **
flatpak_context_bitmask_to_string (guint32 enabled, guint32 valid, const char **names)
{
  guint32 i;
  GPtrArray *array;

  array = g_ptr_array_new ();

  for (i = 0; names[i] != NULL; i++)
    {
      guint32 bitmask = 1 << i;
      if (valid & bitmask)
        {
          if (enabled & bitmask)
            g_ptr_array_add (array, g_strdup (names[i]));
          else
            g_ptr_array_add (array, g_strdup_printf ("!%s", names[i]));
        }
    }

  g_ptr_array_add (array, NULL);
  return (char **) g_ptr_array_free (array, FALSE);
}

static void
flatpak_context_bitmask_to_args (guint32 enabled, guint32 valid, const char **names,
                                 const char *enable_arg, const char *disable_arg,
                                 GPtrArray *args)
{
  guint32 i;

  for (i = 0; names[i] != NULL; i++)
    {
      guint32 bitmask = 1 << i;
      if (valid & bitmask)
        {
          if (enabled & bitmask)
            g_ptr_array_add (args, g_strdup_printf ("%s=%s", enable_arg, names[i]));
          else
            g_ptr_array_add (args, g_strdup_printf ("%s=%s", disable_arg, names[i]));
        }
    }
}


static FlatpakContextShares
flatpak_context_share_from_string (const char *string, GError **error)
{
  FlatpakContextShares shares = flatpak_context_bitmask_from_string (string, flatpak_context_shares);

  if (shares == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_shares);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown share type %s, valid types are: %s"), string, values);
    }

  return shares;
}

static char **
flatpak_context_shared_to_string (FlatpakContextShares shares, FlatpakContextShares valid)
{
  return flatpak_context_bitmask_to_string (shares, valid, flatpak_context_shares);
}

static void
flatpak_context_shared_to_args (FlatpakContextShares shares,
                                FlatpakContextShares valid,
                                GPtrArray           *args)
{
  return flatpak_context_bitmask_to_args (shares, valid, flatpak_context_shares, "--share", "--unshare", args);
}

static FlatpakPolicy
flatpak_policy_from_string (const char *string, GError **error)
{
  const char *policies[] = { "none", "see", "talk", "own", NULL };
  int i;
  g_autofree char *values = NULL;

  for (i = 0; policies[i]; i++)
    {
      if (strcmp (string, policies[i]) == 0)
        return i;
    }

  values = g_strjoinv (", ", (char **) policies);
  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Unknown policy type %s, valid types are: %s"), string, values);

  return -1;
}

static const char *
flatpak_policy_to_string (FlatpakPolicy policy)
{
  if (policy == FLATPAK_POLICY_SEE)
    return "see";
  if (policy == FLATPAK_POLICY_TALK)
    return "talk";
  if (policy == FLATPAK_POLICY_OWN)
    return "own";

  return "none";
}

static gboolean
flatpak_verify_dbus_name (const char *name, GError **error)
{
  const char *name_part;
  g_autofree char *tmp = NULL;

  if (g_str_has_suffix (name, ".*"))
    {
      tmp = g_strndup (name, strlen (name) - 2);
      name_part = tmp;
    }
  else
    {
      name_part = name;
    }

  if (g_dbus_is_name (name_part) && !g_dbus_is_unique_name (name_part))
    return TRUE;

  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Invalid dbus name %s"), name);
  return FALSE;
}

static FlatpakContextSockets
flatpak_context_socket_from_string (const char *string, GError **error)
{
  FlatpakContextSockets sockets = flatpak_context_bitmask_from_string (string, flatpak_context_sockets);

  if (sockets == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_sockets);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown socket type %s, valid types are: %s"), string, values);
    }

  return sockets;
}

static char **
flatpak_context_sockets_to_string (FlatpakContextSockets sockets, FlatpakContextSockets valid)
{
  return flatpak_context_bitmask_to_string (sockets, valid, flatpak_context_sockets);
}

static void
flatpak_context_sockets_to_args (FlatpakContextSockets sockets,
                                 FlatpakContextSockets valid,
                                 GPtrArray            *args)
{
  return flatpak_context_bitmask_to_args (sockets, valid, flatpak_context_sockets, "--socket", "--nosocket", args);
}

static FlatpakContextDevices
flatpak_context_device_from_string (const char *string, GError **error)
{
  FlatpakContextDevices devices = flatpak_context_bitmask_from_string (string, flatpak_context_devices);

  if (devices == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_devices);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown device type %s, valid types are: %s"), string, values);
    }
  return devices;
}

static char **
flatpak_context_devices_to_string (FlatpakContextDevices devices, FlatpakContextDevices valid)
{
  return flatpak_context_bitmask_to_string (devices, valid, flatpak_context_devices);
}

static void
flatpak_context_devices_to_args (FlatpakContextDevices devices,
                                 FlatpakContextDevices valid,
                                 GPtrArray            *args)
{
  return flatpak_context_bitmask_to_args (devices, valid, flatpak_context_devices, "--device", "--nodevice", args);
}

static FlatpakContextFeatures
flatpak_context_feature_from_string (const char *string, GError **error)
{
  FlatpakContextFeatures feature = flatpak_context_bitmask_from_string (string, flatpak_context_features);

  if (feature == 0)
    {
      g_autofree char *values = g_strjoinv (", ", (char **) flatpak_context_features);
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Unknown feature type %s, valid types are: %s"), string, values);
    }

  return feature;
}

static char **
flatpak_context_features_to_string (FlatpakContextFeatures features, FlatpakContextFeatures valid)
{
  return flatpak_context_bitmask_to_string (features, valid, flatpak_context_features);
}

static void
flatpak_context_features_to_args (FlatpakContextFeatures features,
                                  FlatpakContextFeatures valid,
                                  GPtrArray             *args)
{
  return flatpak_context_bitmask_to_args (features, valid, flatpak_context_features, "--allow", "--disallow", args);
}

static void
flatpak_context_add_shares (FlatpakContext      *context,
                            FlatpakContextShares shares)
{
  context->shares_valid |= shares;
  context->shares |= shares;
}

static void
flatpak_context_remove_shares (FlatpakContext      *context,
                               FlatpakContextShares shares)
{
  context->shares_valid |= shares;
  context->shares &= ~shares;
}

static void
flatpak_context_add_sockets (FlatpakContext       *context,
                             FlatpakContextSockets sockets)
{
  context->sockets_valid |= sockets;
  context->sockets |= sockets;
}

static void
flatpak_context_remove_sockets (FlatpakContext       *context,
                                FlatpakContextSockets sockets)
{
  context->sockets_valid |= sockets;
  context->sockets &= ~sockets;
}

static void
flatpak_context_add_devices (FlatpakContext       *context,
                             FlatpakContextDevices devices)
{
  context->devices_valid |= devices;
  context->devices |= devices;
}

static void
flatpak_context_remove_devices (FlatpakContext       *context,
                                FlatpakContextDevices devices)
{
  context->devices_valid |= devices;
  context->devices &= ~devices;
}

static void
flatpak_context_add_features (FlatpakContext        *context,
                              FlatpakContextFeatures features)
{
  context->features_valid |= features;
  context->features |= features;
}

static void
flatpak_context_remove_features (FlatpakContext        *context,
                                 FlatpakContextFeatures features)
{
  context->features_valid |= features;
  context->features &= ~features;
}

static void
flatpak_context_set_env_var (FlatpakContext *context,
                             const char     *name,
                             const char     *value)
{
  g_hash_table_insert (context->env_vars, g_strdup (name), g_strdup (value));
}

void
flatpak_context_set_session_bus_policy (FlatpakContext *context,
                                        const char     *name,
                                        FlatpakPolicy   policy)
{
  g_hash_table_insert (context->session_bus_policy, g_strdup (name), GINT_TO_POINTER (policy));
}

GStrv
flatpak_context_get_session_bus_policy_allowed_own_names (FlatpakContext *context)
{
  GHashTableIter iter;
  gpointer key, value;
  g_autoptr(GPtrArray) names = g_ptr_array_new_with_free_func (g_free);

  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    if (GPOINTER_TO_INT (value) == FLATPAK_POLICY_OWN)
      g_ptr_array_add (names, g_strdup (key));

  g_ptr_array_add (names, NULL);
  return (GStrv) g_ptr_array_free (g_steal_pointer (&names), FALSE);
}

void
flatpak_context_set_system_bus_policy (FlatpakContext *context,
                                       const char     *name,
                                       FlatpakPolicy   policy)
{
  g_hash_table_insert (context->system_bus_policy, g_strdup (name), GINT_TO_POINTER (policy));
}

static void
flatpak_context_apply_generic_policy (FlatpakContext *context,
                                      const char     *key,
                                      const char     *value)
{
  GPtrArray *new = g_ptr_array_new ();
  const char **old_v;
  int i;

  g_assert (strchr (key, '.') != NULL);

  old_v = g_hash_table_lookup (context->generic_policy, key);
  for (i = 0; old_v != NULL && old_v[i] != NULL; i++)
    {
      const char *old = old_v[i];
      const char *cmp1 = old;
      const char *cmp2 = value;
      if (*cmp1 == '!')
        cmp1++;
      if (*cmp2 == '!')
        cmp2++;
      if (strcmp (cmp1, cmp2) != 0)
        g_ptr_array_add (new, g_strdup (old));
    }

  g_ptr_array_add (new, g_strdup (value));
  g_ptr_array_add (new, NULL);

  g_hash_table_insert (context->generic_policy, g_strdup (key),
                       g_ptr_array_free (new, FALSE));
}

static void
flatpak_context_set_persistent (FlatpakContext *context,
                                const char     *path)
{
  g_hash_table_insert (context->persistent, g_strdup (path), GINT_TO_POINTER (1));
}

static gboolean
get_xdg_dir_from_prefix (const char  *prefix,
                         const char **where,
                         const char **dir)
{
  if (strcmp (prefix, "xdg-data") == 0)
    {
      if (where)
        *where = "data";
      if (dir)
        *dir = g_get_user_data_dir ();
      return TRUE;
    }
  if (strcmp (prefix, "xdg-cache") == 0)
    {
      if (where)
        *where = "cache";
      if (dir)
        *dir = g_get_user_cache_dir ();
      return TRUE;
    }
  if (strcmp (prefix, "xdg-config") == 0)
    {
      if (where)
        *where = "config";
      if (dir)
        *dir = g_get_user_config_dir ();
      return TRUE;
    }
  return FALSE;
}

/* This looks only in the xdg dirs (config, cache, data), not the user
   definable ones */
static char *
get_xdg_dir_from_string (const char  *filesystem,
                         const char **suffix,
                         const char **where)
{
  char *slash;
  const char *rest;
  g_autofree char *prefix = NULL;
  const char *dir = NULL;
  gsize len;

  slash = strchr (filesystem, '/');

  if (slash)
    len = slash - filesystem;
  else
    len = strlen (filesystem);

  rest = filesystem + len;
  while (*rest == '/')
    rest++;

  if (suffix != NULL)
    *suffix = rest;

  prefix = g_strndup (filesystem, len);

  if (get_xdg_dir_from_prefix (prefix, where, &dir))
    return g_build_filename (dir, rest, NULL);

  return NULL;
}

static gboolean
get_xdg_user_dir_from_string (const char  *filesystem,
                              const char **config_key,
                              const char **suffix,
                              const char **dir)
{
  char *slash;
  const char *rest;
  g_autofree char *prefix = NULL;
  gsize len;

  slash = strchr (filesystem, '/');

  if (slash)
    len = slash - filesystem;
  else
    len = strlen (filesystem);

  rest = filesystem + len;
  while (*rest == '/')
    rest++;

  if (suffix)
    *suffix = rest;

  prefix = g_strndup (filesystem, len);

  if (strcmp (prefix, "xdg-desktop") == 0)
    {
      if (config_key)
        *config_key = "XDG_DESKTOP_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DESKTOP);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-documents") == 0)
    {
      if (config_key)
        *config_key = "XDG_DOCUMENTS_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DOCUMENTS);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-download") == 0)
    {
      if (config_key)
        *config_key = "XDG_DOWNLOAD_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_DOWNLOAD);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-music") == 0)
    {
      if (config_key)
        *config_key = "XDG_MUSIC_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_MUSIC);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-pictures") == 0)
    {
      if (config_key)
        *config_key = "XDG_PICTURES_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_PICTURES);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-public-share") == 0)
    {
      if (config_key)
        *config_key = "XDG_PUBLICSHARE_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_PUBLIC_SHARE);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-templates") == 0)
    {
      if (config_key)
        *config_key = "XDG_TEMPLATES_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_TEMPLATES);
      return TRUE;
    }
  if (strcmp (prefix, "xdg-videos") == 0)
    {
      if (config_key)
        *config_key = "XDG_VIDEOS_DIR";
      if (dir)
        *dir = g_get_user_special_dir (G_USER_DIRECTORY_VIDEOS);
      return TRUE;
    }
  if (get_xdg_dir_from_prefix (prefix, NULL, dir))
    {
      if (config_key)
        *config_key = NULL;
      return TRUE;
    }
  /* Don't support xdg-run without suffix, because that doesn't work */
  if (strcmp (prefix, "xdg-run") == 0 &&
      *rest != 0)
    {
      if (config_key)
        *config_key = NULL;
      if (dir)
        *dir = flatpak_get_real_xdg_runtime_dir ();
      return TRUE;
    }

  return FALSE;
}

static char *
unparse_filesystem_flags (const char           *path,
                          FlatpakFilesystemMode mode)
{
  g_autoptr(GString) s = g_string_new ("");
  const char *p;

  for (p = path; *p != 0; p++)
    {
      if (*p == ':')
        g_string_append (s, "\\:");
      else if (*p == '\\')
        g_string_append (s, "\\\\");
      else
        g_string_append_c (s, *p);
    }

  switch (mode)
    {
    case FLATPAK_FILESYSTEM_MODE_READ_ONLY:
      g_string_append (s, ":ro");
      break;

    case FLATPAK_FILESYSTEM_MODE_CREATE:
      g_string_append (s, ":create");
      break;

    case FLATPAK_FILESYSTEM_MODE_READ_WRITE:
      break;

    case FLATPAK_FILESYSTEM_MODE_NONE:
      g_string_insert_c (s, 0, '!');
      break;

    default:
      g_warning ("Unexpected filesystem mode %d", mode);
      break;
    }

  return g_string_free (g_steal_pointer (&s), FALSE);
}

static char *
parse_filesystem_flags (const char            *filesystem,
                        FlatpakFilesystemMode *mode_out)
{
  g_autoptr(GString) s = g_string_new ("");
  const char *p, *suffix;
  FlatpakFilesystemMode mode;

  p = filesystem;
  while (*p != 0 && *p != ':')
    {
      if (*p == '\\')
        {
          p++;
          if (*p != 0)
            g_string_append_c (s, *p++);
        }
      else
        g_string_append_c (s, *p++);
    }

  mode = FLATPAK_FILESYSTEM_MODE_READ_WRITE;

  if (*p == ':')
    {
      suffix = p + 1;

      if (strcmp (suffix, "ro") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_READ_ONLY;
      else if (strcmp (suffix, "rw") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_READ_WRITE;
      else if (strcmp (suffix, "create") == 0)
        mode = FLATPAK_FILESYSTEM_MODE_CREATE;
      else if (*suffix != 0)
        g_warning ("Unexpected filesystem suffix %s, ignoring", suffix);
    }

  if (mode_out)
    *mode_out = mode;

  return g_string_free (g_steal_pointer (&s), FALSE);
}

gboolean
flatpak_context_parse_filesystem (const char             *filesystem_and_mode,
                                  char                  **filesystem_out,
                                  FlatpakFilesystemMode  *mode_out,
                                  GError                **error)
{
  g_autofree char *filesystem = parse_filesystem_flags (filesystem_and_mode, mode_out);
  char *slash;

  slash = strchr (filesystem, '/');

  /* Forbid /../ in paths */
  if (slash != NULL)
    {
      if (g_str_has_prefix (slash + 1, "../") ||
          g_str_has_suffix (slash + 1, "/..") ||
          strstr (slash + 1, "/../") != NULL)
        {
          g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                       _("Filesystem location \"%s\" contains \"..\""),
                       filesystem);
          return FALSE;
        }

      /* Convert "//" and "/./" to "/" */
      for (; slash != NULL; slash = strchr (slash + 1, '/'))
        {
          while (TRUE)
            {
              if (slash[1] == '/')
                memmove (slash + 1, slash + 2, strlen (slash + 2) + 1);
              else if (slash[1] == '.' && slash[2] == '/')
                memmove (slash + 1, slash + 3, strlen (slash + 3) + 1);
              else
                break;
            }
        }

      /* Eliminate trailing "/." or "/". */
      while (TRUE)
        {
          slash = strrchr (filesystem, '/');

          if (slash != NULL &&
              ((slash != filesystem && slash[1] == '\0') ||
               (slash[1] == '.' && slash[2] == '\0')))
            *slash = '\0';
          else
            break;
        }

      if (filesystem[0] == '/' && filesystem[1] == '\0')
        {
          /* We don't allow --filesystem=/ as equivalent to host, because
           * it doesn't do what you'd think: --filesystem=host mounts some
           * host directories in /run/host, not in the root. */
          g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                       _("--filesystem=/ is not available, "
                         "use --filesystem=host for a similar result"));
          return FALSE;
        }
    }

  if (g_strv_contains (flatpak_context_special_filesystems, filesystem) ||
      get_xdg_user_dir_from_string (filesystem, NULL, NULL, NULL) ||
      g_str_has_prefix (filesystem, "~/") ||
      g_str_has_prefix (filesystem, "/"))
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_steal_pointer (&filesystem);

      return TRUE;
    }

  if (strcmp (filesystem, "~") == 0)
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_strdup ("home");

      return TRUE;
    }

  if (g_str_has_prefix (filesystem, "home/"))
    {
      if (filesystem_out != NULL)
        *filesystem_out = g_strconcat ("~/", filesystem + 5, NULL);

      return TRUE;
    }

  g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
               _("Unknown filesystem location %s, valid locations are: host, host-os, host-etc, home, xdg-*[/…], ~/dir, /dir"), filesystem);
  return FALSE;
}

/* Note: This only works with valid keys, i.e. they passed flatpak_context_parse_filesystem */
static gboolean
flatpak_filesystem_key_in_home (const char *filesystem)
{
  /* "home" is definitely in home */
  if (strcmp (filesystem, "home") == 0)
    return TRUE;

  /* All the other special fs:es are non-home.
   * Note: This considers absolute paths that are in the homedir as non-home.
   */
  if (g_strv_contains (flatpak_context_special_filesystems, filesystem) ||
      g_str_has_prefix (filesystem, "/"))
    return FALSE;

  /* Files in xdg-run are not in home */
  if (g_str_has_prefix (filesystem, "xdg-run"))
    return FALSE;

  /* All remaining keys (~/, xdg-data, etc) are considered in home,
   * Note: technically $XDG_HOME_DATA could point outside the homedir, but we ignore that.
   */
  return TRUE;
}

static void
flatpak_context_take_filesystem (FlatpakContext        *context,
                                 char                  *fs,
                                 FlatpakFilesystemMode  mode)
{
  g_hash_table_insert (context->filesystems, fs, GINT_TO_POINTER (mode));
}

void
flatpak_context_merge (FlatpakContext *context,
                       FlatpakContext *other)
{
  GHashTableIter iter;
  gpointer key, value;
  gboolean no_home = FALSE;
  gboolean no_host = FALSE;

  context->shares &= ~other->shares_valid;
  context->shares |= other->shares;
  context->shares_valid |= other->shares_valid;
  context->sockets &= ~other->sockets_valid;
  context->sockets |= other->sockets;
  context->sockets_valid |= other->sockets_valid;
  context->devices &= ~other->devices_valid;
  context->devices |= other->devices;
  context->devices_valid |= other->devices_valid;
  context->features &= ~other->features_valid;
  context->features |= other->features;
  context->features_valid |= other->features_valid;

  g_hash_table_iter_init (&iter, other->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->env_vars, g_strdup (key), g_strdup (value));

  g_hash_table_iter_init (&iter, other->persistent);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->persistent, g_strdup (key), value);

  /* We first handle all negative home and host as they override other
     keys than themselves from the parent */
  if (g_hash_table_lookup_extended (other->filesystems,
                                    "host",
                                    NULL, &value))
    {
      FlatpakFilesystemMode host_mode = GPOINTER_TO_INT (value);
      if (host_mode == FLATPAK_FILESYSTEM_MODE_NONE)
        no_host = TRUE;
    }

  if (g_hash_table_lookup_extended (other->filesystems,
                                    "home",
                                    NULL, &value))
    {
      FlatpakFilesystemMode home_mode = GPOINTER_TO_INT (value);
      if (home_mode == FLATPAK_FILESYSTEM_MODE_NONE)
        no_home = TRUE;
    }

  if (no_host)
    {
      g_hash_table_remove_all (context->filesystems);
    }
  else if (no_home)
    {
      g_hash_table_iter_init (&iter, context->filesystems);
      while (g_hash_table_iter_next (&iter, &key, &value))
        {
          if (flatpak_filesystem_key_in_home ((const char *)key))
            g_hash_table_iter_remove (&iter);
        }
    }

  /* Then set the new ones, which includes propagating the nohost and nohome ones. */
  g_hash_table_iter_init (&iter, other->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->filesystems, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->session_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->system_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_hash_table_insert (context->system_bus_policy, g_strdup (key), value);

  g_hash_table_iter_init (&iter, other->generic_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char **policy_values = (const char **) value;
      int i;

      for (i = 0; policy_values[i] != NULL; i++)
        flatpak_context_apply_generic_policy (context, (char *) key, policy_values[i]);
    }
}

static gboolean
option_share_cb (const gchar *option_name,
                 const gchar *value,
                 gpointer     data,
                 GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextShares share;

  share = flatpak_context_share_from_string (value, error);
  if (share == 0)
    return FALSE;

  flatpak_context_add_shares (context, share);

  return TRUE;
}

static gboolean
option_unshare_cb (const gchar *option_name,
                   const gchar *value,
                   gpointer     data,
                   GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextShares share;

  share = flatpak_context_share_from_string (value, error);
  if (share == 0)
    return FALSE;

  flatpak_context_remove_shares (context, share);

  return TRUE;
}

static gboolean
option_socket_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextSockets socket;

  socket = flatpak_context_socket_from_string (value, error);
  if (socket == 0)
    return FALSE;

  if (socket == FLATPAK_CONTEXT_SOCKET_FALLBACK_X11)
    socket |= FLATPAK_CONTEXT_SOCKET_X11;

  flatpak_context_add_sockets (context, socket);

  return TRUE;
}

static gboolean
option_nosocket_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextSockets socket;

  socket = flatpak_context_socket_from_string (value, error);
  if (socket == 0)
    return FALSE;

  if (socket == FLATPAK_CONTEXT_SOCKET_FALLBACK_X11)
    socket |= FLATPAK_CONTEXT_SOCKET_X11;

  flatpak_context_remove_sockets (context, socket);

  return TRUE;
}

static gboolean
option_device_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextDevices device;

  device = flatpak_context_device_from_string (value, error);
  if (device == 0)
    return FALSE;

  flatpak_context_add_devices (context, device);

  return TRUE;
}

static gboolean
option_nodevice_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextDevices device;

  device = flatpak_context_device_from_string (value, error);
  if (device == 0)
    return FALSE;

  flatpak_context_remove_devices (context, device);

  return TRUE;
}

static gboolean
option_allow_cb (const gchar *option_name,
                 const gchar *value,
                 gpointer     data,
                 GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextFeatures feature;

  feature = flatpak_context_feature_from_string (value, error);
  if (feature == 0)
    return FALSE;

  flatpak_context_add_features (context, feature);

  return TRUE;
}

static gboolean
option_disallow_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;
  FlatpakContextFeatures feature;

  feature = flatpak_context_feature_from_string (value, error);
  if (feature == 0)
    return FALSE;

  flatpak_context_remove_features (context, feature);

  return TRUE;
}

static gboolean
option_filesystem_cb (const gchar *option_name,
                      const gchar *value,
                      gpointer     data,
                      GError     **error)
{
  FlatpakContext *context = data;
  g_autofree char *fs = NULL;
  FlatpakFilesystemMode mode;

  if (!flatpak_context_parse_filesystem (value, &fs, &mode, error))
    return FALSE;

  flatpak_context_take_filesystem (context, g_steal_pointer (&fs), mode);
  return TRUE;
}

static gboolean
option_nofilesystem_cb (const gchar *option_name,
                        const gchar *value,
                        gpointer     data,
                        GError     **error)
{
  FlatpakContext *context = data;
  g_autofree char *fs = NULL;
  FlatpakFilesystemMode mode;

  if (!flatpak_context_parse_filesystem (value, &fs, &mode, error))
    return FALSE;

  flatpak_context_take_filesystem (context, g_steal_pointer (&fs),
                                   FLATPAK_FILESYSTEM_MODE_NONE);
  return TRUE;
}

static gboolean
option_env_cb (const gchar *option_name,
               const gchar *value,
               gpointer     data,
               GError     **error)
{
  FlatpakContext *context = data;
  g_auto(GStrv) split = g_strsplit (value, "=", 2);

  if (split == NULL || split[0] == NULL || split[0][0] == 0 || split[1] == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Invalid env format %s"), value);
      return FALSE;
    }

  flatpak_context_set_env_var (context, split[0], split[1]);
  return TRUE;
}

gboolean
flatpak_context_parse_env_block (FlatpakContext *context,
                                 const char *data,
                                 gsize length,
                                 GError **error)
{
  const char *p = data;
  gsize remaining = length;

  /* env_block might not be \0-terminated */
  while (remaining > 0)
    {
      size_t len = strnlen (p, remaining);
      const char *equals;
      g_autofree char *env_var = NULL;
      g_autofree char *env_value = NULL;

      g_assert (len <= remaining);

      equals = memchr (p, '=', len);

      if (equals == NULL || equals == p)
        return glnx_throw (error,
                           "Environment variable must be given in the form VARIABLE=VALUE, not %.*s", (int) len, p);

      env_var = g_strndup (p, equals - p);
      env_value = g_strndup (equals + 1, len - (equals - p) - 1);
      flatpak_context_set_env_var (context, env_var, env_value);
      p += len;
      remaining -= len;

      if (remaining > 0)
        {
          g_assert (*p == '\0');
          p += 1;
          remaining -= 1;
        }
    }

  return TRUE;
}

gboolean
flatpak_context_parse_env_fd (FlatpakContext *context,
                              int fd,
                              GError **error)
{
  g_autoptr(GBytes) env_block = NULL;
  const char *data;
  gsize len;

  env_block = glnx_fd_readall_bytes (fd, NULL, error);

  if (env_block == NULL)
    return FALSE;

  data = g_bytes_get_data (env_block, &len);
  return flatpak_context_parse_env_block (context, data, len, error);
}

static gboolean
option_env_fd_cb (const gchar *option_name,
                  const gchar *value,
                  gpointer     data,
                  GError     **error)
{
  FlatpakContext *context = data;
  guint64 fd;
  gchar *endptr;
  gboolean ret;

  fd = g_ascii_strtoull (value, &endptr, 10);

  if (endptr == NULL || *endptr != '\0' || fd > G_MAXINT)
    return glnx_throw (error, "Not a valid file descriptor: %s", value);

  ret = flatpak_context_parse_env_fd (context, (int) fd, error);

  if (fd >= 3)
    close (fd);

  return ret;
}

static gboolean
option_unset_env_cb (const gchar *option_name,
                     const gchar *value,
                     gpointer     data,
                     GError     **error)
{
  FlatpakContext *context = data;

  if (strchr (value, '=') != NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_FAILED,
                   _("Environment variable name must not contain '=': %s"), value);
      return FALSE;
    }

  flatpak_context_set_env_var (context, value, NULL);
  return TRUE;
}

static gboolean
option_own_name_cb (const gchar *option_name,
                    const gchar *value,
                    gpointer     data,
                    GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_OWN);
  return TRUE;
}

static gboolean
option_talk_name_cb (const gchar *option_name,
                     const gchar *value,
                     gpointer     data,
                     GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_TALK);
  return TRUE;
}

static gboolean
option_no_talk_name_cb (const gchar *option_name,
                        const gchar *value,
                        gpointer     data,
                        GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_session_bus_policy (context, value, FLATPAK_POLICY_NONE);
  return TRUE;
}

static gboolean
option_system_own_name_cb (const gchar *option_name,
                           const gchar *value,
                           gpointer     data,
                           GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_OWN);
  return TRUE;
}

static gboolean
option_system_talk_name_cb (const gchar *option_name,
                            const gchar *value,
                            gpointer     data,
                            GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_TALK);
  return TRUE;
}

static gboolean
option_system_no_talk_name_cb (const gchar *option_name,
                               const gchar *value,
                               gpointer     data,
                               GError     **error)
{
  FlatpakContext *context = data;

  if (!flatpak_verify_dbus_name (value, error))
    return FALSE;

  flatpak_context_set_system_bus_policy (context, value, FLATPAK_POLICY_NONE);
  return TRUE;
}

static gboolean
option_add_generic_policy_cb (const gchar *option_name,
                              const gchar *value,
                              gpointer     data,
                              GError     **error)
{
  FlatpakContext *context = data;
  char *t;
  g_autofree char *key = NULL;
  const char *policy_value;

  t = strchr (value, '=');
  if (t == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }
  policy_value = t + 1;
  key = g_strndup (value, t - value);
  if (strchr (key, '.') == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }

  if (policy_value[0] == '!')
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--add-policy values can't start with \"!\""));
      return FALSE;
    }

  flatpak_context_apply_generic_policy (context, key, policy_value);

  return TRUE;
}

static gboolean
option_remove_generic_policy_cb (const gchar *option_name,
                                 const gchar *value,
                                 gpointer     data,
                                 GError     **error)
{
  FlatpakContext *context = data;
  char *t;
  g_autofree char *key = NULL;
  const char *policy_value;
  g_autofree char *extended_value = NULL;

  t = strchr (value, '=');
  if (t == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }
  policy_value = t + 1;
  key = g_strndup (value, t - value);
  if (strchr (key, '.') == NULL)
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy arguments must be in the form SUBSYSTEM.KEY=VALUE"));
      return FALSE;
    }

  if (policy_value[0] == '!')
    {
      g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
                   _("--remove-policy values can't start with \"!\""));
      return FALSE;
    }

  extended_value = g_strconcat ("!", policy_value, NULL);

  flatpak_context_apply_generic_policy (context, key, extended_value);

  return TRUE;
}

static gboolean
option_persist_cb (const gchar *option_name,
                   const gchar *value,
                   gpointer     data,
                   GError     **error)
{
  FlatpakContext *context = data;

  flatpak_context_set_persistent (context, value);
  return TRUE;
}

static gboolean option_no_desktop_deprecated;

static GOptionEntry context_options[] = {
  { "share", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_share_cb, N_("Share with host"), N_("SHARE") },
  { "unshare", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_unshare_cb, N_("Unshare with host"), N_("SHARE") },
  { "socket", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_socket_cb, N_("Expose socket to app"), N_("SOCKET") },
  { "nosocket", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_nosocket_cb, N_("Don't expose socket to app"), N_("SOCKET") },
  { "device", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_device_cb, N_("Expose device to app"), N_("DEVICE") },
  { "nodevice", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_nodevice_cb, N_("Don't expose device to app"), N_("DEVICE") },
  { "allow", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_allow_cb, N_("Allow feature"), N_("FEATURE") },
  { "disallow", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_disallow_cb, N_("Don't allow feature"), N_("FEATURE") },
  { "filesystem", 0, G_OPTION_FLAG_IN_MAIN | G_OPTION_FLAG_FILENAME, G_OPTION_ARG_CALLBACK, &option_filesystem_cb, N_("Expose filesystem to app (:ro for read-only)"), N_("FILESYSTEM[:ro]") },
  { "nofilesystem", 0, G_OPTION_FLAG_IN_MAIN | G_OPTION_FLAG_FILENAME, G_OPTION_ARG_CALLBACK, &option_nofilesystem_cb, N_("Don't expose filesystem to app"), N_("FILESYSTEM") },
  { "env", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_env_cb, N_("Set environment variable"), N_("VAR=VALUE") },
  { "env-fd", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_env_fd_cb, N_("Read environment variables in env -0 format from FD"), N_("FD") },
  { "unset-env", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_unset_env_cb, N_("Remove variable from environment"), N_("VAR") },
  { "own-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_own_name_cb, N_("Allow app to own name on the session bus"), N_("DBUS_NAME") },
  { "talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_talk_name_cb, N_("Allow app to talk to name on the session bus"), N_("DBUS_NAME") },
  { "no-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_no_talk_name_cb, N_("Don't allow app to talk to name on the session bus"), N_("DBUS_NAME") },
  { "system-own-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_own_name_cb, N_("Allow app to own name on the system bus"), N_("DBUS_NAME") },
  { "system-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_talk_name_cb, N_("Allow app to talk to name on the system bus"), N_("DBUS_NAME") },
  { "system-no-talk-name", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_system_no_talk_name_cb, N_("Don't allow app to talk to name on the system bus"), N_("DBUS_NAME") },
  { "add-policy", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_add_generic_policy_cb, N_("Add generic policy option"), N_("SUBSYSTEM.KEY=VALUE") },
  { "remove-policy", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_remove_generic_policy_cb, N_("Remove generic policy option"), N_("SUBSYSTEM.KEY=VALUE") },
  { "persist", 0, G_OPTION_FLAG_IN_MAIN, G_OPTION_ARG_CALLBACK, &option_persist_cb, N_("Persist home directory subpath"), N_("FILENAME") },
  /* This is not needed/used anymore, so hidden, but we accept it for backwards compat */
  { "no-desktop", 0, G_OPTION_FLAG_IN_MAIN |  G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_NONE, &option_no_desktop_deprecated, N_("Don't require a running session (no cgroups creation)"), NULL },
  { NULL }
};

GOptionEntry *
flatpak_context_get_option_entries (void)
{
  return context_options;
}

GOptionGroup  *
flatpak_context_get_options (FlatpakContext *context)
{
  GOptionGroup *group;

  group = g_option_group_new ("environment",
                              "Runtime Environment",
                              "Runtime Environment",
                              context,
                              NULL);
  g_option_group_set_translation_domain (group, GETTEXT_PACKAGE);

  g_option_group_add_entries (group, context_options);

  return group;
}

static const char *
parse_negated (const char *option, gboolean *negated)
{
  if (option[0] == '!')
    {
      option++;
      *negated = TRUE;
    }
  else
    {
      *negated = FALSE;
    }
  return option;
}

/*
 * Merge the FLATPAK_METADATA_GROUP_CONTEXT,
 * FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
 * FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY and
 * FLATPAK_METADATA_GROUP_ENVIRONMENT groups, and all groups starting
 * with FLATPAK_METADATA_GROUP_PREFIX_POLICY, from metakey into context.
 *
 * This is a merge, not a replace!
 */
gboolean
flatpak_context_load_metadata (FlatpakContext *context,
                               GKeyFile       *metakey,
                               GError        **error)
{
  gboolean remove;
  g_auto(GStrv) groups = NULL;
  gsize i;

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_SHARED, NULL))
    {
      g_auto(GStrv) shares = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                         FLATPAK_METADATA_KEY_SHARED, NULL, error);
      if (shares == NULL)
        return FALSE;

      for (i = 0; shares[i] != NULL; i++)
        {
          FlatpakContextShares share;

          share = flatpak_context_share_from_string (parse_negated (shares[i], &remove), NULL);
          if (share == 0)
            g_debug ("Unknown share type %s", shares[i]);
          else
            {
              if (remove)
                flatpak_context_remove_shares (context, share);
              else
                flatpak_context_add_shares (context, share);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_SOCKETS, NULL))
    {
      g_auto(GStrv) sockets = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                          FLATPAK_METADATA_KEY_SOCKETS, NULL, error);
      if (sockets == NULL)
        return FALSE;

      for (i = 0; sockets[i] != NULL; i++)
        {
          FlatpakContextSockets socket = flatpak_context_socket_from_string (parse_negated (sockets[i], &remove), NULL);
          if (socket == 0)
            g_debug ("Unknown socket type %s", sockets[i]);
          else
            {
              if (remove)
                flatpak_context_remove_sockets (context, socket);
              else
                flatpak_context_add_sockets (context, socket);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_DEVICES, NULL))
    {
      g_auto(GStrv) devices = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                          FLATPAK_METADATA_KEY_DEVICES, NULL, error);
      if (devices == NULL)
        return FALSE;


      for (i = 0; devices[i] != NULL; i++)
        {
          FlatpakContextDevices device = flatpak_context_device_from_string (parse_negated (devices[i], &remove), NULL);
          if (device == 0)
            g_debug ("Unknown device type %s", devices[i]);
          else
            {
              if (remove)
                flatpak_context_remove_devices (context, device);
              else
                flatpak_context_add_devices (context, device);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_FEATURES, NULL))
    {
      g_auto(GStrv) features = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                           FLATPAK_METADATA_KEY_FEATURES, NULL, error);
      if (features == NULL)
        return FALSE;


      for (i = 0; features[i] != NULL; i++)
        {
          FlatpakContextFeatures feature = flatpak_context_feature_from_string (parse_negated (features[i], &remove), NULL);
          if (feature == 0)
            g_debug ("Unknown feature type %s", features[i]);
          else
            {
              if (remove)
                flatpak_context_remove_features (context, feature);
              else
                flatpak_context_add_features (context, feature);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_FILESYSTEMS, NULL))
    {
      g_auto(GStrv) filesystems = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                              FLATPAK_METADATA_KEY_FILESYSTEMS, NULL, error);
      if (filesystems == NULL)
        return FALSE;

      for (i = 0; filesystems[i] != NULL; i++)
        {
          const char *fs = parse_negated (filesystems[i], &remove);
          g_autofree char *filesystem = NULL;
          FlatpakFilesystemMode mode;

          if (!flatpak_context_parse_filesystem (fs, &filesystem, &mode, NULL))
            g_debug ("Unknown filesystem type %s", filesystems[i]);
          else
            {
              if (remove)
                flatpak_context_take_filesystem (context, g_steal_pointer (&filesystem),
                                                 FLATPAK_FILESYSTEM_MODE_NONE);
              else
                flatpak_context_take_filesystem (context, g_steal_pointer (&filesystem), mode);
            }
        }
    }

  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_PERSISTENT, NULL))
    {
      g_auto(GStrv) persistent = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                                             FLATPAK_METADATA_KEY_PERSISTENT, NULL, error);
      if (persistent == NULL)
        return FALSE;

      for (i = 0; persistent[i] != NULL; i++)
        flatpak_context_set_persistent (context, persistent[i]);
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, key, NULL);
          FlatpakPolicy policy;

          if (!flatpak_verify_dbus_name (key, error))
            return FALSE;

          policy = flatpak_policy_from_string (value, NULL);
          if ((int) policy != -1)
            flatpak_context_set_session_bus_policy (context, key, policy);
        }
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, key, NULL);
          FlatpakPolicy policy;

          if (!flatpak_verify_dbus_name (key, error))
            return FALSE;

          policy = flatpak_policy_from_string (value, NULL);
          if ((int) policy != -1)
            flatpak_context_set_system_bus_policy (context, key, policy);
        }
    }

  if (g_key_file_has_group (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT))
    {
      g_auto(GStrv) keys = NULL;
      gsize keys_count;

      keys = g_key_file_get_keys (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, &keys_count, NULL);
      for (i = 0; i < keys_count; i++)
        {
          const char *key = keys[i];
          g_autofree char *value = g_key_file_get_string (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, key, NULL);

          flatpak_context_set_env_var (context, key, value);
        }
    }

  /* unset-environment is higher precedence than Environment, so that
   * we can put unset keys in both places. Old versions of Flatpak will
   * interpret the empty string as unset; new versions will obey
   * unset-environment. */
  if (g_key_file_has_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT, FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT, NULL))
    {
      g_auto(GStrv) vars = NULL;
      gsize vars_count;

      vars = g_key_file_get_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                         FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT,
                                         &vars_count, error);

      if (vars == NULL)
        return FALSE;

      for (i = 0; i < vars_count; i++)
        {
          const char *var = vars[i];

          flatpak_context_set_env_var (context, var, NULL);
        }
    }

  groups = g_key_file_get_groups (metakey, NULL);
  for (i = 0; groups[i] != NULL; i++)
    {
      const char *group = groups[i];
      const char *subsystem;
      int j;

      if (g_str_has_prefix (group, FLATPAK_METADATA_GROUP_PREFIX_POLICY))
        {
          g_auto(GStrv) keys = NULL;
          subsystem = group + strlen (FLATPAK_METADATA_GROUP_PREFIX_POLICY);
          keys = g_key_file_get_keys (metakey, group, NULL, NULL);
          for (j = 0; keys != NULL && keys[j] != NULL; j++)
            {
              const char *key = keys[j];
              g_autofree char *policy_key = g_strdup_printf ("%s.%s", subsystem, key);
              g_auto(GStrv) values = NULL;
              int k;

              values = g_key_file_get_string_list (metakey, group, key, NULL, NULL);
              for (k = 0; values != NULL && values[k] != NULL; k++)
                flatpak_context_apply_generic_policy (context, policy_key,
                                                      values[k]);
            }
        }
    }

  return TRUE;
}

/*
 * Save the FLATPAK_METADATA_GROUP_CONTEXT,
 * FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
 * FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY and
 * FLATPAK_METADATA_GROUP_ENVIRONMENT groups, and all groups starting
 * with FLATPAK_METADATA_GROUP_PREFIX_POLICY, into metakey
 */
void
flatpak_context_save_metadata (FlatpakContext *context,
                               gboolean        flatten,
                               GKeyFile       *metakey)
{
  g_auto(GStrv) shared = NULL;
  g_auto(GStrv) sockets = NULL;
  g_auto(GStrv) devices = NULL;
  g_auto(GStrv) features = NULL;
  g_autoptr(GPtrArray) unset_env = NULL;
  GHashTableIter iter;
  gpointer key, value;
  FlatpakContextShares shares_mask = context->shares;
  FlatpakContextShares shares_valid = context->shares_valid;
  FlatpakContextSockets sockets_mask = context->sockets;
  FlatpakContextSockets sockets_valid = context->sockets_valid;
  FlatpakContextDevices devices_mask = context->devices;
  FlatpakContextDevices devices_valid = context->devices_valid;
  FlatpakContextFeatures features_mask = context->features;
  FlatpakContextFeatures features_valid = context->features_valid;
  g_auto(GStrv) groups = NULL;
  int i;

  if (flatten)
    {
      /* A flattened format means we don't expect this to be merged on top of
         another context. In that case we never need to negate any flags.
         We calculate this by removing the zero parts of the mask from the valid set.
       */
      /* First we make sure only the valid parts of the mask are set, in case we
         got some leftover */
      shares_mask &= shares_valid;
      sockets_mask &= sockets_valid;
      devices_mask &= devices_valid;
      features_mask &= features_valid;

      /* Then just set the valid set to be the mask set */
      shares_valid = shares_mask;
      sockets_valid = sockets_mask;
      devices_valid = devices_mask;
      features_valid = features_mask;
    }

  shared = flatpak_context_shared_to_string (shares_mask, shares_valid);
  sockets = flatpak_context_sockets_to_string (sockets_mask, sockets_valid);
  devices = flatpak_context_devices_to_string (devices_mask, devices_valid);
  features = flatpak_context_features_to_string (features_mask, features_valid);

  if (shared[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_SHARED,
                                  (const char * const *) shared, g_strv_length (shared));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_SHARED,
                             NULL);
    }

  if (sockets[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_SOCKETS,
                                  (const char * const *) sockets, g_strv_length (sockets));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_SOCKETS,
                             NULL);
    }

  if (devices[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_DEVICES,
                                  (const char * const *) devices, g_strv_length (devices));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_DEVICES,
                             NULL);
    }

  if (features[0] != NULL)
    {
      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_FEATURES,
                                  (const char * const *) features, g_strv_length (features));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_FEATURES,
                             NULL);
    }

  if (g_hash_table_size (context->filesystems) > 0)
    {
      g_autoptr(GPtrArray) array = g_ptr_array_new_with_free_func (g_free);

      g_hash_table_iter_init (&iter, context->filesystems);
      while (g_hash_table_iter_next (&iter, &key, &value))
        {
          FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

          g_ptr_array_add (array, unparse_filesystem_flags (key, mode));
        }

      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_FILESYSTEMS,
                                  (const char * const *) array->pdata, array->len);
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_FILESYSTEMS,
                             NULL);
    }

  if (g_hash_table_size (context->persistent) > 0)
    {
      g_autofree char **keys = (char **) g_hash_table_get_keys_as_array (context->persistent, NULL);

      g_key_file_set_string_list (metakey,
                                  FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_PERSISTENT,
                                  (const char * const *) keys, g_strv_length (keys));
    }
  else
    {
      g_key_file_remove_key (metakey,
                             FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_PERSISTENT,
                             NULL);
    }

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY, NULL);
  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (flatten && (policy == 0))
        continue;

      g_key_file_set_string (metakey,
                             FLATPAK_METADATA_GROUP_SESSION_BUS_POLICY,
                             (char *) key, flatpak_policy_to_string (policy));
    }

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY, NULL);
  g_hash_table_iter_init (&iter, context->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (flatten && (policy == 0))
        continue;

      g_key_file_set_string (metakey,
                             FLATPAK_METADATA_GROUP_SYSTEM_BUS_POLICY,
                             (char *) key, flatpak_policy_to_string (policy));
    }

  /* Elements are borrowed from context->env_vars */
  unset_env = g_ptr_array_new ();

  g_key_file_remove_group (metakey, FLATPAK_METADATA_GROUP_ENVIRONMENT, NULL);
  g_hash_table_iter_init (&iter, context->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      if (value != NULL)
        {
          g_key_file_set_string (metakey,
                                 FLATPAK_METADATA_GROUP_ENVIRONMENT,
                                 (char *) key, (char *) value);
        }
      else
        {
          /* In older versions of Flatpak, [Environment] FOO=
           * was interpreted as unsetting - so let's do both. */
          g_key_file_set_string (metakey,
                                 FLATPAK_METADATA_GROUP_ENVIRONMENT,
                                 (char *) key, "");
          g_ptr_array_add (unset_env, key);
        }
    }

  if (unset_env->len > 0)
    {
      g_ptr_array_add (unset_env, NULL);
      g_key_file_set_string_list (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                                  FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT,
                                  (const char * const *) unset_env->pdata,
                                  unset_env->len - 1);
    }
  else
    {
      g_key_file_remove_key (metakey, FLATPAK_METADATA_GROUP_CONTEXT,
                             FLATPAK_METADATA_KEY_UNSET_ENVIRONMENT, NULL);
    }

  groups = g_key_file_get_groups (metakey, NULL);
  for (i = 0; groups[i] != NULL; i++)
    {
      const char *group = groups[i];
      if (g_str_has_prefix (group, FLATPAK_METADATA_GROUP_PREFIX_POLICY))
        g_key_file_remove_group (metakey, group, NULL);
    }

  g_hash_table_iter_init (&iter, context->generic_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      g_auto(GStrv) parts = g_strsplit ((const char *) key, ".", 2);
      g_autofree char *group = NULL;
      g_assert (parts[1] != NULL);
      const char **policy_values = (const char **) value;
      g_autoptr(GPtrArray) new = g_ptr_array_new ();

      for (i = 0; policy_values[i] != NULL; i++)
        {
          const char *policy_value = policy_values[i];

          if (!flatten || policy_value[0] != '!')
            g_ptr_array_add (new, (char *) policy_value);
        }

      if (new->len > 0)
        {
          group = g_strconcat (FLATPAK_METADATA_GROUP_PREFIX_POLICY,
                               parts[0], NULL);
          g_key_file_set_string_list (metakey, group, parts[1],
                                      (const char * const *) new->pdata,
                                      new->len);
        }
    }
}

void
flatpak_context_allow_host_fs (FlatpakContext *context)
{
  flatpak_context_take_filesystem (context, g_strdup ("host"), FLATPAK_FILESYSTEM_MODE_READ_WRITE);
}

gboolean
flatpak_context_get_needs_session_bus_proxy (FlatpakContext *context)
{
  return g_hash_table_size (context->session_bus_policy) > 0;
}

gboolean
flatpak_context_get_needs_system_bus_proxy (FlatpakContext *context)
{
  return g_hash_table_size (context->system_bus_policy) > 0;
}

static gboolean
adds_flags (guint32 old_flags, guint32 new_flags)
{
  return (new_flags & ~old_flags) != 0;
}

static gboolean
adds_bus_policy (GHashTable *old, GHashTable *new)
{
  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, name, gpointer, _new_policy)
    {
      int new_policy = GPOINTER_TO_INT (_new_policy);
      int old_policy = GPOINTER_TO_INT (g_hash_table_lookup (old, name));
      if (new_policy > old_policy)
        return TRUE;
    }

  return FALSE;
}

static gboolean
adds_generic_policy (GHashTable *old, GHashTable *new)
{
  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, key, GPtrArray *, new_values)
    {
      GPtrArray *old_values = g_hash_table_lookup (old, key);
      int i;

      if (new_values == NULL || new_values->len == 0)
        continue;

      if (old_values == NULL || old_values->len == 0)
        return TRUE;

      for (i = 0; i < new_values->len; i++)
        {
          const char *new_value = g_ptr_array_index (new_values, i);

          if (!flatpak_g_ptr_array_contains_string (old_values, new_value))
            return TRUE;
        }
    }

  return FALSE;
}

static gboolean
adds_filesystem_access (GHashTable *old, GHashTable *new)
{
  FlatpakFilesystemMode old_host_mode = GPOINTER_TO_INT (g_hash_table_lookup (old, "host"));

  GLNX_HASH_TABLE_FOREACH_KV (new, const char *, location, gpointer, _new_mode)
    {
      FlatpakFilesystemMode new_mode = GPOINTER_TO_INT (_new_mode);
      FlatpakFilesystemMode old_mode = GPOINTER_TO_INT (g_hash_table_lookup (old, location));

      /* Allow more limited access to the same thing */
      if (new_mode <= old_mode)
        continue;

      /* Allow more limited access if we used to have access to everything */
     if (new_mode <= old_host_mode)
        continue;

     /* For the remainder we have to be pessimistic, for instance even
        if we have home access we can't allow adding access to ~/foo,
        because foo might be a symlink outside home which didn't work
        before but would work with an explicit access to that
        particular file. */

      return TRUE;
    }

  return FALSE;
}


gboolean
flatpak_context_adds_permissions (FlatpakContext *old,
                                  FlatpakContext *new)
{
  /* We allow upgrade to multiarch, that is really not a huge problem.
   * Similarly, having sensible semantics for /dev/shm is
   * not a security concern. */
  guint32 harmless_features = (FLATPAK_CONTEXT_FEATURE_MULTIARCH |
                               FLATPAK_CONTEXT_FEATURE_PER_APP_DEV_SHM);
  guint32 old_sockets;

  if (adds_flags (old->shares & old->shares_valid,
                  new->shares & new->shares_valid))
    return TRUE;

  old_sockets = old->sockets & old->sockets_valid;

  /* If we used to allow X11, also allow new fallback X11,
     as that is actually less permissions */
  if (old_sockets & FLATPAK_CONTEXT_SOCKET_X11)
    old_sockets |= FLATPAK_CONTEXT_SOCKET_FALLBACK_X11;

  if (adds_flags (old_sockets,
                  new->sockets & new->sockets_valid))
    return TRUE;

  if (adds_flags (old->devices & old->devices_valid,
                  new->devices & new->devices_valid))
    return TRUE;

  if (adds_flags ((old->features & old->features_valid) | harmless_features,
                  new->features & new->features_valid))
    return TRUE;

  if (adds_bus_policy (old->session_bus_policy, new->session_bus_policy))
    return TRUE;

  if (adds_bus_policy (old->system_bus_policy, new->system_bus_policy))
    return TRUE;

  if (adds_generic_policy (old->generic_policy, new->generic_policy))
    return TRUE;

  if (adds_filesystem_access (old->filesystems, new->filesystems))
    return TRUE;

  return FALSE;
}

gboolean
flatpak_context_allows_features (FlatpakContext        *context,
                                 FlatpakContextFeatures features)
{
  return (context->features & features) == features;
}

void
flatpak_context_to_args (FlatpakContext *context,
                         GPtrArray      *args)
{
  GHashTableIter iter;
  gpointer key, value;

  flatpak_context_shared_to_args (context->shares, context->shares_valid, args);
  flatpak_context_sockets_to_args (context->sockets, context->sockets_valid, args);
  flatpak_context_devices_to_args (context->devices, context->devices_valid, args);
  flatpak_context_features_to_args (context->features, context->features_valid, args);

  g_hash_table_iter_init (&iter, context->env_vars);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      if (value != NULL)
        g_ptr_array_add (args, g_strdup_printf ("--env=%s=%s", (char *) key, (char *) value));
      else
        g_ptr_array_add (args, g_strdup_printf ("--unset-env=%s", (char *) key));
    }

  g_hash_table_iter_init (&iter, context->persistent);
  while (g_hash_table_iter_next (&iter, &key, &value))
    g_ptr_array_add (args, g_strdup_printf ("--persist=%s", (char *) key));

  g_hash_table_iter_init (&iter, context->session_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *name = key;
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      g_ptr_array_add (args, g_strdup_printf ("--%s-name=%s", flatpak_policy_to_string (policy), name));
    }

  g_hash_table_iter_init (&iter, context->system_bus_policy);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *name = key;
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      g_ptr_array_add (args, g_strdup_printf ("--system-%s-name=%s", flatpak_policy_to_string (policy), name));
    }

  g_hash_table_iter_init (&iter, context->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

      if (mode != FLATPAK_FILESYSTEM_MODE_NONE)
        {
          g_autofree char *fs = unparse_filesystem_flags (key, mode);
          g_ptr_array_add (args, g_strdup_printf ("--filesystem=%s", fs));
        }
      else
        g_ptr_array_add (args, g_strdup_printf ("--nofilesystem=%s", (char *) key));
    }
}

void
flatpak_context_add_bus_filters (FlatpakContext *context,
                                 const char     *app_id,
                                 gboolean        session_bus,
                                 gboolean        sandboxed,
                                 FlatpakBwrap   *bwrap)
{
  GHashTable *ht;
  GHashTableIter iter;
  gpointer key, value;

  flatpak_bwrap_add_arg (bwrap, "--filter");
  if (app_id && session_bus)
    {
      if (!sandboxed)
        {
          flatpak_bwrap_add_arg_printf (bwrap, "--own=%s.*", app_id);
          flatpak_bwrap_add_arg_printf (bwrap, "--own=org.mpris.MediaPlayer2.%s.*", app_id);
        }
      else
        flatpak_bwrap_add_arg_printf (bwrap, "--own=%s.Sandboxed.*", app_id);
    }

  if (session_bus)
    ht = context->session_bus_policy;
  else
    ht = context->system_bus_policy;

  g_hash_table_iter_init (&iter, ht);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      FlatpakPolicy policy = GPOINTER_TO_INT (value);

      if (policy > 0)
        flatpak_bwrap_add_arg_printf (bwrap, "--%s=%s",
                                      flatpak_policy_to_string (policy),
                                      (char *) key);
    }
}

void
flatpak_context_reset_non_permissions (FlatpakContext *context)
{
  g_hash_table_remove_all (context->env_vars);
}

void
flatpak_context_reset_permissions (FlatpakContext *context)
{
  context->shares_valid = 0;
  context->sockets_valid = 0;
  context->devices_valid = 0;
  context->features_valid = 0;

  context->shares = 0;
  context->sockets = 0;
  context->devices = 0;
  context->features = 0;

  g_hash_table_remove_all (context->persistent);
  g_hash_table_remove_all (context->filesystems);
  g_hash_table_remove_all (context->session_bus_policy);
  g_hash_table_remove_all (context->system_bus_policy);
  g_hash_table_remove_all (context->generic_policy);
}

void
flatpak_context_make_sandboxed (FlatpakContext *context)
{
  /* We drop almost everything from the app permission, except
   * multiarch which is inherited, to make sure app code keeps
   * running. */
  context->shares_valid &= 0;
  context->sockets_valid &= 0;
  context->devices_valid &= 0;
  context->features_valid &= FLATPAK_CONTEXT_FEATURE_MULTIARCH;

  context->shares &= context->shares_valid;
  context->sockets &= context->sockets_valid;
  context->devices &= context->devices_valid;
  context->features &= context->features_valid;

  g_hash_table_remove_all (context->persistent);
  g_hash_table_remove_all (context->filesystems);
  g_hash_table_remove_all (context->session_bus_policy);
  g_hash_table_remove_all (context->system_bus_policy);
  g_hash_table_remove_all (context->generic_policy);
}

const char *dont_mount_in_root[] = {
  ".", "..", "lib", "lib32", "lib64", "bin", "sbin", "usr", "boot", "root",
  "tmp", "etc", "app", "run", "proc", "sys", "dev", "var", NULL
};

static void
flatpak_context_export (FlatpakContext *context,
                        FlatpakExports *exports,
                        GFile          *app_id_dir,
                        GPtrArray       *extra_app_id_dirs,
                        gboolean        do_create,
                        gchar         **xdg_dirs_conf_out,
                        gboolean       *home_access_out)
{
  gboolean home_access = FALSE;
  g_autoptr(GString) xdg_dirs_conf = NULL;
  FlatpakFilesystemMode fs_mode, os_mode, etc_mode, home_mode;
  GHashTableIter iter;
  gpointer key, value;

  if (xdg_dirs_conf_out != NULL)
    xdg_dirs_conf = g_string_new ("");

  fs_mode = GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host"));
  if (fs_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    {
      DIR *dir;
      struct dirent *dirent;

      g_debug ("Allowing host-fs access");
      home_access = TRUE;

      /* Bind mount most dirs in / into the new root */
      dir = opendir ("/");
      if (dir != NULL)
        {
          while ((dirent = readdir (dir)))
            {
              g_autofree char *path = NULL;

              if (g_strv_contains (dont_mount_in_root, dirent->d_name))
                continue;

              path = g_build_filename ("/", dirent->d_name, NULL);
              flatpak_exports_add_path_expose (exports, fs_mode, path);
            }
          closedir (dir);
        }
      flatpak_exports_add_path_expose (exports, fs_mode, "/run/media");
    }

  os_mode = MAX (GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host-os")),
                   fs_mode);

  if (os_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    flatpak_exports_add_host_os_expose (exports, os_mode);

  etc_mode = MAX (GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "host-etc")),
                   fs_mode);

  if (etc_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    flatpak_exports_add_host_etc_expose (exports, etc_mode);

  home_mode = GPOINTER_TO_INT (g_hash_table_lookup (context->filesystems, "home"));
  if (home_mode != FLATPAK_FILESYSTEM_MODE_NONE)
    {
      g_debug ("Allowing homedir access");
      home_access = TRUE;

      flatpak_exports_add_path_expose (exports, MAX (home_mode, fs_mode), g_get_home_dir ());
    }

  g_hash_table_iter_init (&iter, context->filesystems);
  while (g_hash_table_iter_next (&iter, &key, &value))
    {
      const char *filesystem = key;
      FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);

      if (g_strv_contains (flatpak_context_special_filesystems, filesystem))
        continue;

      if (g_str_has_prefix (filesystem, "xdg-"))
        {
          const char *path, *rest = NULL;
          const char *config_key = NULL;
          g_autofree char *subpath = NULL;

          if (!get_xdg_user_dir_from_string (filesystem, &config_key, &rest, &path))
            {
              g_warning ("Unsupported xdg dir %s", filesystem);
              continue;
            }

          if (path == NULL)
            continue; /* Unconfigured, ignore */

          if (strcmp (path, g_get_home_dir ()) == 0)
            {
              /* xdg-user-dirs sets disabled dirs to $HOME, and its in general not a good
                 idea to set full access to $HOME other than explicitly, so we ignore
                 these */
              g_debug ("Xdg dir %s is $HOME (i.e. disabled), ignoring", filesystem);
              continue;
            }

          subpath = g_build_filename (path, rest, NULL);

          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (subpath, 0755);

          if (g_file_test (subpath, G_FILE_TEST_EXISTS))
            {
              if (config_key && xdg_dirs_conf)
                g_string_append_printf (xdg_dirs_conf, "%s=\"%s\"\n",
                                        config_key, path);

              flatpak_exports_add_path_expose_or_hide (exports, mode, subpath);
            }
        }
      else if (g_str_has_prefix (filesystem, "~/"))
        {
          g_autofree char *path = NULL;

          path = g_build_filename (g_get_home_dir (), filesystem + 2, NULL);

          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (path, 0755);

          if (g_file_test (path, G_FILE_TEST_EXISTS))
            flatpak_exports_add_path_expose_or_hide (exports, mode, path);
        }
      else if (g_str_has_prefix (filesystem, "/"))
        {
          if (mode == FLATPAK_FILESYSTEM_MODE_CREATE && do_create)
            g_mkdir_with_parents (filesystem, 0755);

          if (g_file_test (filesystem, G_FILE_TEST_EXISTS))
            flatpak_exports_add_path_expose_or_hide (exports, mode, filesystem);
        }
      else
        {
          g_warning ("Unexpected filesystem arg %s", filesystem);
        }
    }

  if (app_id_dir)
    {
      g_autoptr(GFile) apps_dir = g_file_get_parent (app_id_dir);
      int i;
      /* Hide the .var/app dir by default (unless explicitly made visible) */
      flatpak_exports_add_path_tmpfs (exports, flatpak_file_get_path_cached (apps_dir));
      /* But let the app write to the per-app dir in it */
      flatpak_exports_add_path_expose (exports, FLATPAK_FILESYSTEM_MODE_READ_WRITE,
                                       flatpak_file_get_path_cached (app_id_dir));

      if (extra_app_id_dirs != NULL)
        {
          for (i = 0; i < extra_app_id_dirs->len; i++)
            {
              GFile *extra_app_id_dir = g_ptr_array_index (extra_app_id_dirs, i);
              flatpak_exports_add_path_expose (exports, FLATPAK_FILESYSTEM_MODE_READ_WRITE,
                                               flatpak_file_get_path_cached (extra_app_id_dir));
            }
        }
    }

  if (home_access_out != NULL)
    *home_access_out = home_access;

  if (xdg_dirs_conf_out != NULL)
    {
      g_assert (xdg_dirs_conf != NULL);
      *xdg_dirs_conf_out = g_string_free (g_steal_pointer (&xdg_dirs_conf), FALSE);
    }
}

FlatpakExports *
flatpak_context_get_exports (FlatpakContext *context,
                             const char     *app_id)
{
  g_autoptr(GFile) app_id_dir = flatpak_get_data_dir (app_id);

  return flatpak_context_get_exports_full (context,
                                           app_id_dir, NULL,
                                           FALSE, FALSE, NULL, NULL);
}

FlatpakRunFlags
flatpak_context_get_run_flags (FlatpakContext *context)
{
  FlatpakRunFlags flags = 0;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_DEVEL))
    flags |= FLATPAK_RUN_FLAG_DEVEL;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_MULTIARCH))
    flags |= FLATPAK_RUN_FLAG_MULTIARCH;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_BLUETOOTH))
    flags |= FLATPAK_RUN_FLAG_BLUETOOTH;

  if (flatpak_context_allows_features (context, FLATPAK_CONTEXT_FEATURE_CANBUS))
    flags |= FLATPAK_RUN_FLAG_CANBUS;

  return flags;
}

FlatpakExports *
flatpak_context_get_exports_full (FlatpakContext *context,
                                  GFile          *app_id_dir,
                                  GPtrArray      *extra_app_id_dirs,
                                  gboolean        do_create,
                                  gboolean        include_default_dirs,
                                  gchar         **xdg_dirs_conf_out,
                                  gboolean       *home_access_out)
{
  g_autoptr(FlatpakExports) exports = flatpak_exports_new ();

  flatpak_context_export (context, exports,
                          app_id_dir, extra_app_id_dirs,
                          do_create, xdg_dirs_conf_out, home_access_out);

  if (include_default_dirs)
    {
      g_autoptr(GFile) user_flatpak_dir = NULL;

      /* Hide the flatpak dir by default (unless explicitly made visible) */
      user_flatpak_dir = flatpak_get_user_base_dir_location ();
      flatpak_exports_add_path_tmpfs (exports, flatpak_file_get_path_cached (user_flatpak_dir));

      /* Ensure we always have a homedir */
      flatpak_exports_add_path_dir (exports, g_get_home_dir ());
    }

  return g_steal_pointer (&exports);
}

void
flatpak_context_append_bwrap_filesystem (FlatpakContext  *context,
                                         FlatpakBwrap    *bwrap,
                                         const char      *app_id,
                                         GFile           *app_id_dir,
                                         FlatpakExports  *exports,
                                         const char      *xdg_dirs_conf,
                                         gboolean         home_access)
{
  GHashTableIter iter;
  gpointer key, value;

  if (app_id_dir != NULL)
    flatpak_run_apply_env_appid (bwrap, app_id_dir);

  if (!home_access)
    {
      /* Enable persistent mapping only if no access to real home dir */

      g_hash_table_iter_init (&iter, context->persistent);
      while (g_hash_table_iter_next (&iter, &key, NULL))
        {
          const char *persist = key;
          g_autofree char *src = g_build_filename (g_get_home_dir (), ".var/app", app_id, persist, NULL);
          g_autofree char *dest = g_build_filename (g_get_home_dir (), persist, NULL);

          g_mkdir_with_parents (src, 0755);

          flatpak_bwrap_add_bind_arg (bwrap, "--bind", src, dest);
        }
    }

  if (app_id_dir != NULL)
    {
      g_autofree char *user_runtime_dir = flatpak_get_real_xdg_runtime_dir ();
      g_autofree char *run_user_app_dst = g_strdup_printf ("/run/flatpak/app/%s", app_id);
      g_autofree char *run_user_app_src = g_build_filename (user_runtime_dir, "app", app_id, NULL);

      if (glnx_shutil_mkdir_p_at (AT_FDCWD,
                                  run_user_app_src,
                                  0700,
                                  NULL,
                                  NULL))
        flatpak_bwrap_add_args (bwrap,
                                "--bind", run_user_app_src, run_user_app_dst,
                                NULL);

      /* Later, we'll make $XDG_RUNTIME_DIR/app a symlink to /run/flatpak/app */
      flatpak_bwrap_add_runtime_dir_member (bwrap, "app");
    }

  /* This actually outputs the args for the hide/expose operations
   * in the exports */
  flatpak_exports_append_bwrap_args (exports, bwrap);

  /* Special case subdirectories of the cache, config and data xdg
   * dirs.  If these are accessible explicitly, then we bind-mount
   * these in the app-id dir. This allows applications to explicitly
   * opt out of keeping some config/cache/data in the app-specific
   * directory.
   */
  if (app_id_dir)
    {
      g_hash_table_iter_init (&iter, context->filesystems);
      while (g_hash_table_iter_next (&iter, &key, &value))
        {
          const char *filesystem = key;
          FlatpakFilesystemMode mode = GPOINTER_TO_INT (value);
          g_autofree char *xdg_path = NULL;
          const char *rest, *where;

          xdg_path = get_xdg_dir_from_string (filesystem, &rest, &where);

          if (xdg_path != NULL && *rest != 0 &&
              mode >= FLATPAK_FILESYSTEM_MODE_READ_ONLY)
            {
              g_autoptr(GFile) app_version = g_file_get_child (app_id_dir, where);
              g_autoptr(GFile) app_version_subdir = g_file_resolve_relative_path (app_version, rest);

              if (g_file_test (xdg_path, G_FILE_TEST_IS_DIR) ||
                  g_file_test (xdg_path, G_FILE_TEST_IS_REGULAR))
                {
                  g_autofree char *xdg_path_in_app = g_file_get_path (app_version_subdir);
                  flatpak_bwrap_add_bind_arg (bwrap,
                                              mode == FLATPAK_FILESYSTEM_MODE_READ_ONLY ? "--ro-bind" : "--bind",
                                              xdg_path, xdg_path_in_app);
                }
            }
        }
    }

  if (home_access && app_id_dir != NULL)
    {
      g_autofree char *src_path = g_build_filename (g_get_user_config_dir (),
                                                    "user-dirs.dirs",
                                                    NULL);
      g_autofree char *path = g_build_filename (flatpak_file_get_path_cached (app_id_dir),
                                                "config/user-dirs.dirs", NULL);
      if (g_file_test (src_path, G_FILE_TEST_EXISTS))
        flatpak_bwrap_add_bind_arg (bwrap, "--ro-bind", src_path, path);
    }
  else if (xdg_dirs_conf != NULL && xdg_dirs_conf[0] != '\0' && app_id_dir != NULL)
    {
      g_autofree char *path =
        g_build_filename (flatpak_file_get_path_cached (app_id_dir),
                          "config/user-dirs.dirs", NULL);

      flatpak_bwrap_add_args_data (bwrap, "xdg-config-dirs",
                                   xdg_dirs_conf, strlen (xdg_dirs_conf), path, NULL);
    }
}