/*

 * Copyright (C) 2022 Eric Curtin <ericcurtin17@gmail.com>

 *

 * 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 of the licence 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 <https://www.gnu.org/licenses/>.

 */

#include "config.h"

#include "ostree-bootloader-aboot.h"

#include "ostree-deployment-private.h"

#include "ostree-libarchive-private.h"

#include "ostree-sysroot-private.h"

#include "otutil.h"

#include <sys/mount.h>

#include <stdint.h>

#include <string.h>

/* This is specific to aboot and zipl today, but in the future we could also

 * use it for the grub2-mkconfig case.

 */

static const char aboot_requires_execute_path[] = "boot/ostree-bootloader-update.stamp";

struct _OstreeBootloaderAboot

{

  GObject parent_instance;

  OstreeSysroot *sysroot;

};

typedef GObjectClass OstreeBootloaderAbootClass;

static void _ostree_bootloader_aboot_bootloader_iface_init (OstreeBootloaderInterface *iface);

G_DEFINE_TYPE_WITH_CODE (OstreeBootloaderAboot, _ostree_bootloader_aboot, G_TYPE_OBJECT,

                         G_IMPLEMENT_INTERFACE (OSTREE_TYPE_BOOTLOADER,

                                                _ostree_bootloader_aboot_bootloader_iface_init));

static gboolean

_ostree_bootloader_aboot_query (OstreeBootloader *bootloader, gboolean *out_is_active,

                                GCancellable *cancellable, GError **error)

{

  /* We don't auto-detect this one; should be explicitly chosen right now.

   * see also https://github.com/coreos/coreos-assembler/pull/849

   */

  *out_is_active = FALSE;

  return TRUE;

}

static const char *

_ostree_bootloader_aboot_get_name (OstreeBootloader *bootloader)

{

  return "aboot";

}

static gboolean

_ostree_bootloader_aboot_write_config (OstreeBootloader *bootloader, int bootversion,

                                       GPtrArray *new_deployments, GCancellable *cancellable,

                                       GError **error)

{

  OstreeBootloaderAboot *self = OSTREE_BOOTLOADER_ABOOT (bootloader);

  /* Write our stamp file */

  if (!glnx_file_replace_contents_at (self->sysroot->sysroot_fd, aboot_requires_execute_path,

                                      (guint8 *)"", 0, GLNX_FILE_REPLACE_NODATASYNC, cancellable,

                                      error))

    return FALSE;

  return TRUE;

}

static gboolean

_ostree_aboot_get_bls_config (OstreeBootloaderAboot *self, int bootversion, gchar **aboot,

                              gchar **abootcfg, gchar **version, gchar **vmlinuz, gchar **initramfs,

                              gchar **options, GCancellable *cancellable, GError **error)

{

  g_autoptr (GPtrArray) configs = NULL;

  if (!_ostree_sysroot_read_boot_loader_configs (self->sysroot, bootversion, &configs, cancellable,

                                                 error))

    return glnx_prefix_error (error, "aboot: loading bls configs");

  if (!configs || configs->len == 0)

    return glnx_throw (error, "aboot: no bls config");

  OstreeBootconfigParser *parser = (OstreeBootconfigParser *)g_ptr_array_index (configs, 0);

  const gchar *val = NULL;

  val = ostree_bootconfig_parser_get (parser, "aboot");

  if (!val)

    {

      return glnx_throw (error, "aboot: no \"aboot\" key in bootloader config");

    }

  *aboot = g_strdup (val);

  val = ostree_bootconfig_parser_get (parser, "abootcfg");

  if (!val)

    {

      return glnx_throw (error, "aboot: no \"abootcfg\" key in bootloader config");

    }

  *abootcfg = g_strdup (val);

  val = ostree_bootconfig_parser_get (parser, "version");

  if (!val)

    return glnx_throw (error, "aboot: no \"version\" key in bootloader config");

  *version = g_strdup (val);

  val = ostree_bootconfig_parser_get (parser, "linux");

  if (!val)

    return glnx_throw (error, "aboot: no \"linux\" key in bootloader config");

  *vmlinuz = g_build_filename ("/boot", val, NULL);

  val = ostree_bootconfig_parser_get (parser, "initrd");

  if (!val)

    return glnx_throw (error, "aboot: no \"initrd\" key in bootloader config");

  *initramfs = g_build_filename ("/boot", val, NULL);

  val = ostree_bootconfig_parser_get (parser, "options");

  if (!val)

    return glnx_throw (error, "aboot: no \"options\" key in bootloader config");

  *options = g_strdup (val);

  return TRUE;

}

static void

child_setup_fchdir (gpointer data)

{

  int fd = (int)(uintptr_t)data;

  int rc = fchdir (fd);

  g_assert (rc == 0);

}

static gboolean

_ostree_bootloader_aboot_post_bls_sync (OstreeBootloader *bootloader, int bootversion,

                                        GCancellable *cancellable, GError **error)

{

  OstreeBootloaderAboot *self = OSTREE_BOOTLOADER_ABOOT (bootloader);

  /* Note that unlike the grub2-mkconfig backend, we make no attempt to

   * chroot().

   */

  // g_assert (self->sysroot->booted_deployment);

  if (!glnx_fstatat_allow_noent (self->sysroot->sysroot_fd, aboot_requires_execute_path, NULL, 0,

                                 error))

    return FALSE;

  /* If there's no stamp file, nothing to do */

  if (errno == ENOENT)

    return TRUE;

  g_autofree gchar *aboot = NULL;

  g_autofree gchar *abootcfg = NULL;

  g_autofree gchar *version = NULL;

  g_autofree gchar *vmlinuz = NULL;

  g_autofree gchar *initramfs = NULL;

  g_autofree gchar *options = NULL;

  if (!_ostree_aboot_get_bls_config (self, bootversion, &aboot, &abootcfg, &version, &vmlinuz,

                                     &initramfs, &options, cancellable, error))

    return FALSE;

  const char *const aboot_argv[]

      = { "aboot-deploy", "-r", ".", "-c", abootcfg, "-o", options, aboot, NULL };

  int estatus;

  if (!g_spawn_sync (NULL, (char **)aboot_argv, NULL, G_SPAWN_SEARCH_PATH, child_setup_fchdir,

                     (gpointer)(uintptr_t)self->sysroot->sysroot_fd, NULL, NULL, &estatus, error))

    {

      return FALSE;

    }

  if (!g_spawn_check_exit_status (estatus, error))

    {

      return FALSE;

    }

  if (!glnx_unlinkat (self->sysroot->sysroot_fd, aboot_requires_execute_path, 0, error))

    {

      return FALSE;

    }

  return TRUE;

}

static void

_ostree_bootloader_aboot_finalize (GObject *object)

{

  OstreeBootloaderAboot *self = OSTREE_BOOTLOADER_ABOOT (object);

  g_clear_object (&self->sysroot);

  G_OBJECT_CLASS (_ostree_bootloader_aboot_parent_class)->finalize (object);

}

void

_ostree_bootloader_aboot_init (OstreeBootloaderAboot *self)

{

}

static void

_ostree_bootloader_aboot_bootloader_iface_init (OstreeBootloaderInterface *iface)

{

  iface->query = _ostree_bootloader_aboot_query;

  iface->get_name = _ostree_bootloader_aboot_get_name;

  iface->write_config = _ostree_bootloader_aboot_write_config;

  iface->post_bls_sync = _ostree_bootloader_aboot_post_bls_sync;

}

void

_ostree_bootloader_aboot_class_init (OstreeBootloaderAbootClass *class)

{

  GObjectClass *object_class = G_OBJECT_CLASS (class);

  object_class->finalize = _ostree_bootloader_aboot_finalize;

}

OstreeBootloaderAboot *

_ostree_bootloader_aboot_new (OstreeSysroot *sysroot)

{

  OstreeBootloaderAboot *self = g_object_new (OSTREE_TYPE_BOOTLOADER_ABOOT, NULL);

  self->sysroot = g_object_ref (sysroot);

  return self;

}