/*

 * Copyright 2017 Richard Hughes <richard@hughsie.com>

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 */

#define G_LOG_DOMAIN "FuKernel"

#include "config.h"

#include "fu-kernel-search-path-private.h"

#include "fu-path.h"

/**

 * FuKernelSearchPathLocker:

 *

 * Easily reset the firmware search path.

 */

struct _FuKernelSearchPathLocker {

  GObject parent_instance;

  gchar *path;

  gchar *old_path;

};

G_DEFINE_TYPE(FuKernelSearchPathLocker, fu_kernel_search_path_locker, G_TYPE_OBJECT)

/**

 * fu_kernel_search_path_locker_get_path:

 * @self: a #FuDfuFirmware

 *

 * Gets the kernel search path set using this locker.

 *

 * Returns: the path set with fu_kernel_search_path_locker_new()

 *

 * Since: 2.0.7

 **/

const gchar *

fu_kernel_search_path_locker_get_path(FuKernelSearchPathLocker *self)

{

  g_return_val_if_fail(FU_IS_KERNEL_SEARCH_PATH_LOCKER(self), NULL);

  return self->path;

}

/* private */

gchar *

fu_kernel_search_path_get_current(GError **error)

{

  gsize sz = 0;

  g_autofree gchar *sys_fw_search_path = NULL;

  g_autofree gchar *contents = NULL;

  sys_fw_search_path = fu_path_from_kind(FU_PATH_KIND_FIRMWARE_SEARCH);

  if (!g_file_get_contents(sys_fw_search_path, &contents, &sz, error))

    return NULL;

  /* sanity check */

  if (contents == NULL || sz == 0) {

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "failed to get firmware search path from %s",

          sys_fw_search_path);

    return NULL;

  }

  /* remove newline character */

  if (contents[sz - 1] == '\n')

    contents[sz - 1] = 0;

  g_debug("read firmware search path (%" G_GSIZE_FORMAT "): %s", sz, contents);

  return g_steal_pointer(&contents);

}

static gboolean

fu_kernel_search_path_set_current(const gchar *path, GError **error)

{

  g_autofree gchar *sys_fw_search_path_prm = NULL;

  g_return_val_if_fail(path != NULL, FALSE);

  g_return_val_if_fail(strlen(path) < PATH_MAX, FALSE);

  g_debug("writing firmware search path (%" G_GSIZE_FORMAT "): %s", strlen(path), path);

  sys_fw_search_path_prm = fu_path_from_kind(FU_PATH_KIND_FIRMWARE_SEARCH);

  return g_file_set_contents_full(sys_fw_search_path_prm,

          path,

          strlen(path),

          G_FILE_SET_CONTENTS_NONE,

          0644,

          error);

}

static gboolean

fu_kernel_search_path_locker_close(FuKernelSearchPathLocker *self, GError **error)

{

  if (self->old_path == NULL)

    return TRUE;

  if (!fu_kernel_search_path_set_current(self->old_path, error))

    return FALSE;

  g_clear_pointer(&self->old_path, g_free);

  return TRUE;

}

/**

 * fu_kernel_search_path_locker_new:

 * @path: the new devivce path

 * @error: (nullable): optional return location for an error

 *

 * Sets the kernel firmware search path. When the #FuKernelSearchPathLocker is deallocated path

 * is restored to the previous value.

 *

 * This object is typically called using g_autoptr() but the device can also be

 * manually closed using g_clear_object().

 *

 * Returns: (transfer full): a #FuKernelSearchPathLocker, or %NULL on error

 *

 * Since: 2.0.6

 **/

FuKernelSearchPathLocker *

fu_kernel_search_path_locker_new(const gchar *path, GError **error)

{

  g_autofree gchar *old_path = NULL;

  g_autoptr(FuKernelSearchPathLocker) self = NULL;

  g_return_val_if_fail(path != NULL, NULL);

  g_return_val_if_fail(error == NULL || *error == NULL, NULL);

  /* create object */

  self = g_object_new(FU_TYPE_KERNEL_SEARCH_PATH_LOCKER, NULL);

  self->path = g_strdup(path);

  old_path = fu_kernel_search_path_get_current(error);

  if (old_path == NULL)

    return NULL;

  /* set the new path if different */

  if (g_strcmp0(self->old_path, path) != 0) {

    self->old_path = g_steal_pointer(&old_path);

    if (!fu_kernel_search_path_set_current(path, error))

      return NULL;

  }

  /* success */

  return g_steal_pointer(&self);

}

static void

fu_kernel_search_path_locker_dispose(GObject *obj)

{

  FuKernelSearchPathLocker *self = FU_KERNEL_SEARCH_PATH_LOCKER(obj);

  if (self->old_path != NULL) {

    g_autoptr(GError) error = NULL;

    if (!fu_kernel_search_path_locker_close(self, &error))

      g_warning("failed to restore path: %s", error->message);

  }

  G_OBJECT_CLASS(fu_kernel_search_path_locker_parent_class)->dispose(obj);

}

static void

fu_kernel_search_path_locker_finalize(GObject *obj)

{

  FuKernelSearchPathLocker *self = FU_KERNEL_SEARCH_PATH_LOCKER(obj);

  g_free(self->path);

  g_free(self->old_path);

  G_OBJECT_CLASS(fu_kernel_search_path_locker_parent_class)->finalize(obj);

}

static void

fu_kernel_search_path_locker_class_init(FuKernelSearchPathLockerClass *klass)

{

  GObjectClass *object_class = G_OBJECT_CLASS(klass);

  object_class->dispose = fu_kernel_search_path_locker_dispose;

  object_class->finalize = fu_kernel_search_path_locker_finalize;

}

static void

fu_kernel_search_path_locker_init(FuKernelSearchPathLocker *self)

{

}