/*

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

 *

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

 */

#define G_LOG_DOMAIN "FuCommon"

#include "config.h"

#include <errno.h>

#include <glib/gstdio.h>

#ifdef HAVE_UTSNAME_H

#include <sys/utsname.h>

#endif

#include "fu-input-stream.h"

#include "fu-kernel.h"

#include "fu-path.h"

#include "fu-string.h"

#include "fu-version-common.h"

/**

 * fu_kernel_locked_down:

 *

 * Determines if kernel lockdown in effect

 *

 * Since: 1.8.2

 **/

gboolean

fu_kernel_locked_down(void)

{

#ifdef __linux__

  gsize len = 0;

  g_autofree gchar *fname = fu_path_build(FU_PATH_KIND_SYSFSDIR_SECURITY, "lockdown", NULL);

  g_autofree gchar *data = NULL;

  g_auto(GStrv) options = NULL;

  if (!g_file_test(fname, G_FILE_TEST_EXISTS))

    return FALSE;

  if (!g_file_get_contents(fname, &data, &len, NULL))

    return FALSE;

  if (len < 1)

    return FALSE;

  options = g_strsplit(data, " ", -1);

  for (guint i = 0; options[i] != NULL; i++) {

    if (g_strcmp0(options[i], "[none]") == 0)

      return FALSE;

  }

  return TRUE;

#else

  return FALSE;

#endif

}

/**

 * fu_kernel_check_version:

 * @minimum_kernel: (not nullable): The minimum kernel version to check against

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

 *

 * Determines if the system is running at least a certain required kernel version

 *

 * Since: 1.8.2

 **/

gboolean

fu_kernel_check_version(const gchar *minimum_kernel, GError **error)

{

#ifdef HAVE_UTSNAME_H

  struct utsname name_tmp = {0};

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

  g_return_val_if_fail(minimum_kernel != NULL, FALSE);

  if (uname(&name_tmp) < 0) {

    g_set_error_literal(error,

            FWUPD_ERROR,

            FWUPD_ERROR_INTERNAL,

            "failed to read kernel version");

    return FALSE;

  }

  if (fu_version_compare(name_tmp.release, minimum_kernel, FWUPD_VERSION_FORMAT_TRIPLET) <

      0) {

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "kernel %s doesn't meet minimum %s",

          name_tmp.release,

          minimum_kernel);

    return FALSE;

  }

  return TRUE;

#else

  g_set_error_literal(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "platform doesn't support checking for minimum Linux kernel");

  return FALSE;

#endif

}

typedef struct {

  GHashTable *hash;

  GHashTable *values;

} FuKernelConfigHelper;

static gboolean

fu_kernel_parse_config_line_cb(GString *token, guint token_idx, gpointer user_data, GError **error)

{

  g_auto(GStrv) kv = NULL;

  FuKernelConfigHelper *helper = (FuKernelConfigHelper *)user_data;

  GRefString *value;

  if (token->len == 0)

    return TRUE;

  if (token->str[0] == '#')

    return TRUE;

  kv = g_strsplit(token->str, "=", 2);

  if (g_strv_length(kv) != 2) {

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INVALID_DATA,

          "invalid format for '%s'",

          token->str);

    return FALSE;

  }

  value = g_hash_table_lookup(helper->values, kv[1]);

  if (value != NULL) {

    g_hash_table_insert(helper->hash, g_strdup(kv[0]), g_ref_string_acquire(value));

  } else {

    g_hash_table_insert(helper->hash, g_strdup(kv[0]), g_ref_string_new(kv[1]));

  }

  return TRUE;

}

/**

 * fu_kernel_parse_config:

 * @buf: (not nullable): cmdline to parse

 * @bufsz: size of @bufsz

 *

 * Parses all the kernel options into a hash table. Commented out options are not included.

 *

 * Returns: (transfer container) (element-type utf8 utf8): config keys

 *

 * Since: 1.9.6

 **/

GHashTable *

fu_kernel_parse_config(const gchar *buf, gsize bufsz, GError **error)

{

  g_autoptr(GHashTable) hash = g_hash_table_new_full(g_str_hash,

                 g_str_equal,

                 g_free,

                 (GDestroyNotify)g_ref_string_release);

  g_autoptr(GHashTable) values = g_hash_table_new_full(g_str_hash,

                   g_str_equal,

                   NULL,

                   (GDestroyNotify)g_ref_string_release);

  FuKernelConfigHelper helper = {.hash = hash, .values = values};

  const gchar *value_keys[] = {"y", "m", "0", NULL};

  g_return_val_if_fail(buf != NULL, NULL);

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

  /* add 99.9% of the most common keys to avoid thousands of small allocations */

  for (guint i = 0; value_keys[i] != NULL; i++) {

    g_hash_table_insert(values,

            (gpointer)value_keys[i],

            g_ref_string_new(value_keys[i]));

  }

  if (!fu_strsplit_full(buf, bufsz, "\n", fu_kernel_parse_config_line_cb, &helper, error))

    return NULL;

  return g_steal_pointer(&hash);

}

#ifdef __linux__

static gchar *

fu_kernel_get_config_path(GError **error)

{

#ifdef HAVE_UTSNAME_H

  struct utsname name_tmp;

  g_autofree gchar *config_fn = NULL;

  memset(&name_tmp, 0, sizeof(struct utsname));

  if (uname(&name_tmp) < 0) {

    g_set_error_literal(error,

            FWUPD_ERROR,

            FWUPD_ERROR_INTERNAL,

            "failed to read kernel version");

    return NULL;

  }

  config_fn = g_strdup_printf("config-%s", name_tmp.release);

  return fu_path_build(FU_PATH_KIND_HOSTFS_BOOT, config_fn, NULL);

#else

  g_set_error_literal(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "platform does not support uname");

  return NULL;

#endif

}

#endif

/**

 * fu_kernel_get_config:

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

 *

 * Loads all the kernel options into a hash table. Commented out options are not included.

 *

 * Returns: (transfer container) (element-type utf8 utf8): options from the kernel

 *

 * Since: 1.8.5

 **/

GHashTable *

fu_kernel_get_config(GError **error)

{

#ifdef __linux__

  gsize bufsz = 0;

  g_autofree gchar *buf = NULL;

  g_autofree gchar *fn = NULL;

  g_autofree gchar *config_fngz = fu_path_build(FU_PATH_KIND_PROCFS, "config.gz", NULL);

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

  /* try /proc/config.gz -- which will only work with CONFIG_IKCONFIG */

  if (g_file_test(config_fngz, G_FILE_TEST_EXISTS)) {

    g_autoptr(GBytes) payload = NULL;

    g_autoptr(GConverter) conv = NULL;

    g_autoptr(GFile) file = g_file_new_for_path(config_fngz);

    g_autoptr(GInputStream) istream1 = NULL;

    g_autoptr(GInputStream) istream2 = NULL;

    istream1 = G_INPUT_STREAM(g_file_read(file, NULL, error));

    if (istream1 == NULL)

      return NULL;

    conv = G_CONVERTER(g_zlib_decompressor_new(G_ZLIB_COMPRESSOR_FORMAT_GZIP));

    istream2 = g_converter_input_stream_new(istream1, conv);

    payload = fu_input_stream_read_bytes(istream2, 0, G_MAXSIZE, NULL, error);

    if (payload == NULL)

      return NULL;

    return fu_kernel_parse_config(g_bytes_get_data(payload, NULL),

                g_bytes_get_size(payload),

                error);

  }

  /* fall back to /boot/config-$(uname -r) */

  fn = fu_kernel_get_config_path(error);

  if (fn == NULL)

    return NULL;

  if (!g_file_get_contents(fn, &buf, &bufsz, error))

    return NULL;

  return fu_kernel_parse_config(buf, bufsz, error);

#else

  g_set_error_literal(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "platform does not support getting the kernel config");

  return NULL;

#endif

}

/**

 * fu_kernel_parse_cmdline:

 * @buf: (not nullable): cmdline to parse

 * @bufsz: size of @bufsz

 *

 * Parses all the kernel key/values into a hash table, respecting double quotes when required.

 *

 * Returns: (transfer container) (element-type utf8 utf8): keys from the cmdline

 *

 * Since: 1.9.1

 **/

GHashTable *

fu_kernel_parse_cmdline(const gchar *buf, gsize bufsz)

{

  gboolean is_escape = FALSE;

  g_autoptr(GHashTable) hash = NULL;

  g_autoptr(GString) acc = g_string_new(NULL);

  g_return_val_if_fail(buf != NULL, NULL);

  hash = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);

  if (bufsz == 0)

    return g_steal_pointer(&hash);

  for (gsize i = 0; i < bufsz; i++) {

    if (!is_escape && (buf[i] == ' ' || buf[i] == '\n') && acc->len > 0) {

      g_auto(GStrv) kv = g_strsplit(acc->str, "=", 2);

      g_hash_table_insert(hash, g_strdup(kv[0]), g_strdup(kv[1]));

      g_string_set_size(acc, 0);

      continue;

    }

    if (buf[i] == '"') {

      is_escape = !is_escape;

      continue;

    }

    g_string_append_c(acc, buf[i]);

  }

  if (acc->len > 0) {

    g_auto(GStrv) kv = g_strsplit(acc->str, "=", 2);

    g_hash_table_insert(hash, g_strdup(kv[0]), g_strdup(kv[1]));

  }

  /* success */

  return g_steal_pointer(&hash);

}

/**

 * fu_kernel_get_cmdline:

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

 *

 * Loads all the kernel /proc/cmdline key/values into a hash table.

 *

 * Returns: (transfer container) (element-type utf8 utf8): keys from the kernel command line

 *

 * Since: 1.8.5

 **/

GHashTable *

fu_kernel_get_cmdline(GError **error)

{

#ifdef __linux__

  gsize bufsz = 0;

  g_autofree gchar *buf = NULL;

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

  if (!g_file_get_contents("/proc/cmdline", &buf, &bufsz, error))

    return NULL;

  return fu_kernel_parse_cmdline(buf, bufsz);

#else

  g_set_error_literal(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INTERNAL,

          "platform does not support getting the kernel cmdline");

  return NULL;

#endif

}

gboolean

fu_kernel_check_cmdline_mutable(GError **error)

{

  g_autofree gchar *grubby_path = NULL;

  g_auto(GStrv) config_files = g_new0(gchar *, 3);

  /* not found */

  grubby_path = fu_path_find_program("grubby", error);

  if (grubby_path == NULL)

    return FALSE;

  /* check all the config files are writable */

  config_files[0] = fu_path_build(FU_PATH_KIND_HOSTFS_BOOT, "grub2", "grub.cfg", NULL);

  config_files[1] = fu_path_build(FU_PATH_KIND_SYSCONFDIR, "grub.cfg", NULL);

  for (guint i = 0; config_files[i] != NULL; i++) {

    g_autoptr(GFile) file = g_file_new_for_path(config_files[i]);

    g_autoptr(GFileInfo) info = NULL;

    g_autoptr(GError) error_local = NULL;

    if (!g_file_query_exists(file, NULL))

      continue;

    info = g_file_query_info(file,

           G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE,

           G_FILE_QUERY_INFO_NONE,

           NULL,

           &error_local);

    if (info == NULL) {

      g_warning("failed to get info for %s: %s",

          config_files[i],

          error_local->message);

      continue;

    }

    if (!g_file_info_get_attribute_boolean(info, G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE)) {

      g_set_error(error,

            FWUPD_ERROR,

            FWUPD_ERROR_NOT_SUPPORTED,

            "%s is not writable",

            config_files[i]);

      return FALSE;

    }

  }

  /* success */

  return TRUE;

}

static gboolean

fu_kernel_set_commandline(const gchar *arg, gboolean enable, GError **error)

{

  g_autofree gchar *output = NULL;

  g_autofree gchar *arg_string = NULL;

  g_autofree gchar *grubby_path = NULL;

  const gchar *argv_grubby[] = {"", "--update-kernel=DEFAULT", "", NULL};

  grubby_path = fu_path_find_program("grubby", error);

  if (grubby_path == NULL) {

    g_prefix_error_literal(error, "failed to find grubby: ");

    return FALSE;

  }

  if (enable)

    arg_string = g_strdup_printf("--args=%s", arg);

  else

    arg_string = g_strdup_printf("--remove-args=%s", arg);

  argv_grubby[0] = grubby_path;

  argv_grubby[2] = arg_string;

  return g_spawn_sync(NULL,

          (gchar **)argv_grubby,

          NULL,

          G_SPAWN_DEFAULT,

          NULL,

          NULL,

          &output,

          NULL,

          NULL,

          error);

}

/**

 * fu_kernel_add_cmdline_arg:

 * @arg: (not nullable): key to set

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

 *

 * Add a kernel command line argument.

 *

 * Returns: %TRUE if successful

 *

 * Since: 1.9.5

 **/

gboolean

fu_kernel_add_cmdline_arg(const gchar *arg, GError **error)

{

  return fu_kernel_set_commandline(arg, TRUE, error);

}

/**

 * fu_kernel_remove_cmdline_arg:

 * @arg: (not nullable): key to set

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

 *

 * Remove a kernel command line argument.

 *

 * Returns: %TRUE if successful

 *

 * Since: 1.9.5

 **/

gboolean

fu_kernel_remove_cmdline_arg(const gchar *arg, GError **error)

{

  return fu_kernel_set_commandline(arg, FALSE, error);

}