/*

 * Copyright 2022 Richard Hughes <richard@hughsie.com>

 *

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

 */

#define G_LOG_DOMAIN "FuFirmware"

#include "config.h"

#include "fu-byte-array.h"

#include "fu-bytes.h"

#include "fu-common.h"

#include "fu-dump.h"

#include "fu-fdt-firmware.h"

#include "fu-fdt-image.h"

#include "fu-fdt-struct.h"

#include "fu-input-stream.h"

#include "fu-mem.h"

/**

 * FuFdtFirmware:

 *

 * A Flattened DeviceTree firmware image.

 *

 * Documented:

 * https://devicetree-specification.readthedocs.io/en/latest/chapter5-flattened-format.html

 *

 * See also: [class@FuFirmware]

 */

typedef struct {

  guint32 cpuid;

} FuFdtFirmwarePrivate;

G_DEFINE_TYPE_WITH_PRIVATE(FuFdtFirmware, fu_fdt_firmware, FU_TYPE_FIRMWARE)

#define GET_PRIVATE(o) (fu_fdt_firmware_get_instance_private(o))

#define FDT_LAST_COMP_VERSION 2

#define FDT_DEPTH_MAX       128

static GString *

fu_fdt_firmware_string_new_safe(const guint8 *buf, gsize bufsz, gsize offset, GError **error)

{

  g_autoptr(GString) str = g_string_new(NULL);

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

    if (buf[i] == '\0')

      return g_steal_pointer(&str);

    g_string_append_c(str, (gchar)buf[i]);

  }

  g_set_error_literal(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INVALID_DATA,

          "buffer not NULL terminated");

  return NULL;

}

static void

fu_fdt_firmware_export(FuFirmware *firmware, FuFirmwareExportFlags flags, XbBuilderNode *bn)

{

  FuFdtFirmware *self = FU_FDT_FIRMWARE(firmware);

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  fu_xmlb_builder_insert_kx(bn, "cpuid", priv->cpuid);

}

/**

 * fu_fdt_firmware_get_cpuid:

 * @self: a #FuFdtFirmware

 *

 * Gets the CPUID.

 *

 * Returns: integer

 *

 * Since: 1.8.2

 **/

guint32

fu_fdt_firmware_get_cpuid(FuFdtFirmware *self)

{

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  g_return_val_if_fail(FU_IS_FDT_FIRMWARE(self), 0x0);

  return priv->cpuid;

}

/**

 * fu_fdt_firmware_set_cpuid:

 * @self: a #FuFdtFirmware

 * @cpuid: integer value

 *

 * Sets the CPUID.

 *

 * Since: 1.8.2

 **/

void

fu_fdt_firmware_set_cpuid(FuFdtFirmware *self, guint32 cpuid)

{

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  g_return_if_fail(FU_IS_FDT_FIRMWARE(self));

  priv->cpuid = cpuid;

}

/**

 * fu_fdt_firmware_get_image_by_path:

 * @self: a #FuFdtFirmware

 * @path: ID path, e.g. `/images/firmware-1`

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

 *

 * Gets the FDT image for a specific path.

 *

 * Returns: (transfer full): a #FuFirmware, or %NULL

 *

 * Since: 1.8.2

 **/

FuFdtImage *

fu_fdt_firmware_get_image_by_path(FuFdtFirmware *self, const gchar *path, GError **error)

{

  g_auto(GStrv) paths = NULL;

  g_autoptr(FuFirmware) img_current = g_object_ref(FU_FIRMWARE(self));

  g_return_val_if_fail(FU_IS_FDT_FIRMWARE(self), NULL);

  g_return_val_if_fail(path != NULL, NULL);

  g_return_val_if_fail(path[0] != '\0', NULL);

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

  paths = g_strsplit(path, "/", -1);

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

    const gchar *id = paths[i];

    g_autoptr(FuFirmware) img_tmp = NULL;

    /* special case for empty */

    if (id[0] == '\0')

      id = NULL;

    img_tmp = fu_firmware_get_image_by_id(img_current, id, error);

    if (img_tmp == NULL)

      return NULL;

    g_set_object(&img_current, img_tmp);

  }

  /* success */

  return FU_FDT_IMAGE(g_steal_pointer(&img_current));

}

static gboolean

fu_fdt_firmware_parse_dt_struct(FuFdtFirmware *self, GBytes *fw, GByteArray *strtab, GError **error)

{

  gsize bufsz = 0;

  gsize offset = 0;

  guint depth = 0;

  gboolean has_end = FALSE;

  const guint8 *buf = g_bytes_get_data(fw, &bufsz);

  g_autoptr(FuFirmware) firmware_current = g_object_ref(FU_FIRMWARE(self));

  /* debug */

  fu_dump_bytes(G_LOG_DOMAIN, "dt_struct", fw);

  /* parse */

  while (offset < bufsz) {

    guint32 token = 0;

    /* read tag from aligned offset */

    offset = fu_common_align_up(offset, FU_FIRMWARE_ALIGNMENT_4);

    if (!fu_memread_uint32_safe(buf, bufsz, offset, &token, G_BIG_ENDIAN, error))

      return FALSE;

    offset += sizeof(guint32);

    /* nothing to do */

    if (token == FU_FDT_TOKEN_NOP)

      continue;

    /* END */

    if (token == FU_FDT_TOKEN_END) {

      if (firmware_current != FU_FIRMWARE(self)) {

        g_set_error_literal(error,

                FWUPD_ERROR,

                FWUPD_ERROR_INVALID_DATA,

                "got END with unclosed node");

        return FALSE;

      }

      has_end = TRUE;

      break;

    }

    /* BEGIN NODE */

    if (token == FU_FDT_TOKEN_BEGIN_NODE) {

      g_autoptr(GString) str = NULL;

      g_autoptr(FuFirmware) image = NULL;

      /* sanity check */

      if (depth++ > FDT_DEPTH_MAX) {

        g_set_error(error,

              FWUPD_ERROR,

              FWUPD_ERROR_INVALID_DATA,

              "node depth exceeded maximum: 0x%x",

              (guint)FDT_DEPTH_MAX);

        return FALSE;

      }

      str = fu_fdt_firmware_string_new_safe(buf, bufsz, offset, error);

      if (str == NULL)

        return FALSE;

      offset += str->len + 1;

      image = fu_fdt_image_new();

      if (str->len > 0)

        fu_firmware_set_id(image, str->str);

      fu_firmware_set_offset(image, offset);

      if (!fu_firmware_add_image_full(firmware_current, image, error))

        return FALSE;

      g_set_object(&firmware_current, image);

      continue;

    }

    /* END NODE */

    if (token == FU_FDT_TOKEN_END_NODE) {

      if (firmware_current == FU_FIRMWARE(self)) {

        g_set_error_literal(error,

                FWUPD_ERROR,

                FWUPD_ERROR_INVALID_DATA,

                "got END NODE with no node to end");

        return FALSE;

      }

      g_set_object(&firmware_current, fu_firmware_get_parent(firmware_current));

      if (depth > 0)

        depth--;

      continue;

    }

    /* PROP */

    if (token == FU_FDT_TOKEN_PROP) {

      guint32 prop_len;

      guint32 prop_nameoff;

      g_autoptr(GBytes) blob = NULL;

      g_autoptr(GString) str = NULL;

      g_autoptr(GByteArray) st_prp = NULL;

      /* sanity check */

      if (firmware_current == FU_FIRMWARE(self)) {

        g_set_error_literal(error,

                FWUPD_ERROR,

                FWUPD_ERROR_INVALID_DATA,

                "got PROP with unopen node");

        return FALSE;

      }

      /* parse */

      st_prp = fu_struct_fdt_prop_parse(buf, bufsz, offset, error);

      if (st_prp == NULL)

        return FALSE;

      prop_len = fu_struct_fdt_prop_get_len(st_prp);

      prop_nameoff = fu_struct_fdt_prop_get_nameoff(st_prp);

      offset += st_prp->len;

      /* add property */

      str = fu_fdt_firmware_string_new_safe(strtab->data,

                    strtab->len,

                    prop_nameoff,

                    error);

      if (str == NULL) {

        g_prefix_error(error, "invalid strtab offset 0x%x: ", prop_nameoff);

        return FALSE;

      }

      blob = fu_bytes_new_offset(fw, offset, prop_len, error);

      if (blob == NULL)

        return FALSE;

      fu_fdt_image_set_attr(FU_FDT_IMAGE(firmware_current), str->str, blob);

      offset += prop_len;

      continue;

    }

    /* unknown token */

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INVALID_DATA,

          "invalid token 0x%x @0%x",

          token,

          (guint)offset);

    return FALSE;

  }

  /* did not see FDT_END */

  if (!has_end)

    g_warning("did not see FDT_END, perhaps size_dt_struct is invalid?");

  /* success */

  return TRUE;

}

static gboolean

fu_fdt_firmware_parse_mem_rsvmap(FuFdtFirmware *self,

         GInputStream *stream,

         gsize offset,

         GError **error)

{

  gsize streamsz = 0;

  /* parse */

  if (!fu_input_stream_size(stream, &streamsz, error))

    return FALSE;

  for (; offset < streamsz; offset += FU_STRUCT_FDT_RESERVE_ENTRY_SIZE) {

    guint64 address = 0;

    guint64 size = 0;

    g_autoptr(GByteArray) st_res = NULL;

    st_res = fu_struct_fdt_reserve_entry_parse_stream(stream, offset, error);

    if (st_res == NULL)

      return FALSE;

    address = fu_struct_fdt_reserve_entry_get_address(st_res);

    size = fu_struct_fdt_reserve_entry_get_size(st_res);

    g_debug("mem_rsvmap: 0x%x, 0x%x", (guint)address, (guint)size);

    if (address == 0x0 && size == 0x0)

      break;

  }

  /* success */

  return TRUE;

}

static gboolean

fu_fdt_firmware_validate(FuFirmware *firmware, GInputStream *stream, gsize offset, GError **error)

{

  return fu_struct_fdt_validate_stream(stream, offset, error);

}

static gboolean

fu_fdt_firmware_parse(FuFirmware *firmware,

          GInputStream *stream,

          FuFirmwareParseFlags flags,

          GError **error)

{

  FuFdtFirmware *self = FU_FDT_FIRMWARE(firmware);

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  guint32 totalsize;

  gsize streamsz = 0;

  guint32 off_mem_rsvmap = 0;

  g_autoptr(GByteArray) st_hdr = NULL;

  /* sanity check */

  st_hdr = fu_struct_fdt_parse_stream(stream, 0x0, error);

  if (st_hdr == NULL)

    return FALSE;

  if (!fu_input_stream_size(stream, &streamsz, error))

    return FALSE;

  totalsize = fu_struct_fdt_get_totalsize(st_hdr);

  if (totalsize > streamsz) {

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INVALID_DATA,

          "truncated image, got 0x%x, expected >= 0x%x",

          (guint)streamsz,

          (guint)totalsize);

    return FALSE;

  }

  fu_firmware_set_size(firmware, totalsize);

  /* read header */

  priv->cpuid = fu_struct_fdt_get_boot_cpuid_phys(st_hdr);

  off_mem_rsvmap = fu_struct_fdt_get_off_mem_rsvmap(st_hdr);

  if (off_mem_rsvmap != 0x0) {

    if (!fu_fdt_firmware_parse_mem_rsvmap(self, stream, off_mem_rsvmap, error))

      return FALSE;

  }

  if (fu_struct_fdt_get_last_comp_version(st_hdr) < FDT_LAST_COMP_VERSION) {

    g_set_error(error,

          FWUPD_ERROR,

          FWUPD_ERROR_INVALID_DATA,

          "invalid header version, got 0x%x, expected >= 0x%x",

          (guint)fu_struct_fdt_get_last_comp_version(st_hdr),

          (guint)FDT_LAST_COMP_VERSION);

    return FALSE;

  }

  fu_firmware_set_version_raw(firmware, fu_struct_fdt_get_version(st_hdr));

  /* parse device tree struct */

  if (fu_struct_fdt_get_size_dt_struct(st_hdr) != 0x0 &&

      fu_struct_fdt_get_size_dt_strings(st_hdr) != 0x0) {

    g_autoptr(GByteArray) dt_strings = NULL;

    g_autoptr(GByteArray) dt_struct = NULL;

    g_autoptr(GBytes) dt_struct_buf = NULL;

    dt_strings =

        fu_input_stream_read_byte_array(stream,

                fu_struct_fdt_get_off_dt_strings(st_hdr),

                fu_struct_fdt_get_size_dt_strings(st_hdr),

                NULL,

                error);

    if (dt_strings == NULL)

      return FALSE;

    dt_struct =

        fu_input_stream_read_byte_array(stream,

                fu_struct_fdt_get_off_dt_struct(st_hdr),

                fu_struct_fdt_get_size_dt_struct(st_hdr),

                NULL,

                error);

    if (dt_struct == NULL)

      return FALSE;

    if (dt_struct->len != fu_struct_fdt_get_size_dt_struct(st_hdr)) {

      g_set_error_literal(error,

              FWUPD_ERROR,

              FWUPD_ERROR_INVALID_DATA,

              "invalid firmware -- dt_struct invalid");

      return FALSE;

    }

    dt_struct_buf =

        g_byte_array_free_to_bytes(g_steal_pointer(&dt_struct)); /* nocheck:blocked */

    if (!fu_fdt_firmware_parse_dt_struct(self, dt_struct_buf, dt_strings, error))

      return FALSE;

  }

  /* success */

  return TRUE;

}

typedef struct {

  GByteArray *dt_strings;

  GByteArray *dt_struct;

  GHashTable *strtab;

} FuFdtFirmwareBuildHelper;

static guint32

fu_fdt_firmware_append_to_strtab(FuFdtFirmwareBuildHelper *helper, const gchar *key)

{

  gpointer tmp = NULL;

  guint32 offset;

  /* already exists */

  if (g_hash_table_lookup_extended(helper->strtab, key, NULL, &tmp))

    return GPOINTER_TO_UINT(tmp);

  g_debug("adding strtab: %s", key);

  offset = helper->dt_strings->len;

  g_byte_array_append(helper->dt_strings, (const guint8 *)key, strlen(key));

  fu_byte_array_append_uint8(helper->dt_strings, 0x0);

  g_hash_table_insert(helper->strtab, g_strdup(key), GUINT_TO_POINTER(offset));

  return offset;

}

static gboolean

fu_fdt_firmware_write_image(FuFdtFirmware *self,

          FuFdtImage *img,

          FuFdtFirmwareBuildHelper *helper,

          guint depth,

          GError **error)

{

  const gchar *id = fu_firmware_get_id(FU_FIRMWARE(img));

  g_autoptr(GPtrArray) images = fu_firmware_get_images(FU_FIRMWARE(img));

  g_autoptr(GPtrArray) attrs = fu_fdt_image_get_attrs(img);

  /* sanity check */

  if (depth > 0 && id == NULL) {

    g_set_error_literal(error,

            FWUPD_ERROR,

            FWUPD_ERROR_INVALID_DATA,

            "child FuFdtImage requires ID");

    return FALSE;

  }

  /* BEGIN_NODE, ID, NUL */

  fu_byte_array_append_uint32(helper->dt_struct, FU_FDT_TOKEN_BEGIN_NODE, G_BIG_ENDIAN);

  if (id != NULL) {

    g_byte_array_append(helper->dt_struct, (const guint8 *)id, strlen(id) + 1);

  } else {

    fu_byte_array_append_uint8(helper->dt_struct, 0x0);

  }

  fu_byte_array_align_up(helper->dt_struct, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  /* write properties */

  for (guint i = 0; i < attrs->len; i++) {

    const gchar *key = g_ptr_array_index(attrs, i);

    g_autoptr(GBytes) blob = NULL;

    g_autoptr(GByteArray) st_prp = fu_struct_fdt_prop_new();

    blob = fu_fdt_image_get_attr(img, key, error);

    if (blob == NULL)

      return FALSE;

    fu_byte_array_append_uint32(helper->dt_struct, FU_FDT_TOKEN_PROP, G_BIG_ENDIAN);

    fu_struct_fdt_prop_set_len(st_prp, g_bytes_get_size(blob));

    fu_struct_fdt_prop_set_nameoff(st_prp,

                 fu_fdt_firmware_append_to_strtab(helper, key));

    g_byte_array_append(helper->dt_struct, st_prp->data, st_prp->len);

    fu_byte_array_append_bytes(helper->dt_struct, blob);

    fu_byte_array_align_up(helper->dt_struct, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  }

  /* write children, recursively */

  for (guint i = 0; i < images->len; i++) {

    FuFdtImage *img_child = g_ptr_array_index(images, i);

    if (!fu_fdt_firmware_write_image(self, img_child, helper, depth + 1, error))

      return FALSE;

  }

  /* END_NODE */

  fu_byte_array_append_uint32(helper->dt_struct, FU_FDT_TOKEN_END_NODE, G_BIG_ENDIAN);

  return TRUE;

}

static GByteArray *

fu_fdt_firmware_write(FuFirmware *firmware, GError **error)

{

  FuFdtFirmware *self = FU_FDT_FIRMWARE(firmware);

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  guint32 off_dt_struct;

  guint32 off_dt_strings;

  guint32 off_mem_rsvmap;

  g_autoptr(GByteArray) dt_strings = g_byte_array_new();

  g_autoptr(GByteArray) dt_struct = g_byte_array_new();

  g_autoptr(GHashTable) strtab = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);

  g_autoptr(GPtrArray) images = fu_firmware_get_images(firmware);

  g_autoptr(GByteArray) st_hdr = fu_struct_fdt_new();

  g_autoptr(GByteArray) mem_rsvmap = fu_struct_fdt_reserve_entry_new();

  FuFdtFirmwareBuildHelper helper = {

      .dt_strings = dt_strings,

      .dt_struct = dt_struct,

      .strtab = strtab,

  };

  /* empty mem_rsvmap */

  off_mem_rsvmap = fu_common_align_up(st_hdr->len, FU_FIRMWARE_ALIGNMENT_4);

  /* dt_struct */

  off_dt_struct =

      fu_common_align_up(off_mem_rsvmap + mem_rsvmap->len, FU_FIRMWARE_ALIGNMENT_4);

  /* only one root node supported */

  if (images->len != 1) {

    g_set_error_literal(error, FWUPD_ERROR, FWUPD_ERROR_INVALID_DATA, "no root node");

    return NULL;

  }

  if (!fu_fdt_firmware_write_image(self,

           FU_FDT_IMAGE(g_ptr_array_index(images, 0)),

           &helper,

           0,

           error))

    return NULL;

  fu_byte_array_append_uint32(dt_struct, FU_FDT_TOKEN_END, G_BIG_ENDIAN);

  /* dt_strings */

  off_dt_strings =

      fu_common_align_up(off_dt_struct + dt_struct->len, FU_FIRMWARE_ALIGNMENT_4);

  /* write header */

  fu_struct_fdt_set_totalsize(st_hdr, off_dt_strings + dt_strings->len);

  fu_struct_fdt_set_off_dt_struct(st_hdr, off_dt_struct);

  fu_struct_fdt_set_off_dt_strings(st_hdr, off_dt_strings);

  fu_struct_fdt_set_off_mem_rsvmap(st_hdr, off_mem_rsvmap);

  fu_struct_fdt_set_version(st_hdr, fu_firmware_get_version_raw(firmware));

  fu_struct_fdt_set_boot_cpuid_phys(st_hdr, priv->cpuid);

  fu_struct_fdt_set_size_dt_strings(st_hdr, dt_strings->len);

  fu_struct_fdt_set_size_dt_struct(st_hdr, dt_struct->len);

  fu_byte_array_align_up(st_hdr, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  /* write mem_rsvmap, dt_struct, dt_strings */

  g_byte_array_append(st_hdr, mem_rsvmap->data, mem_rsvmap->len);

  fu_byte_array_align_up(st_hdr, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  g_byte_array_append(st_hdr, dt_struct->data, dt_struct->len);

  fu_byte_array_align_up(st_hdr, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  g_byte_array_append(st_hdr, dt_strings->data, dt_strings->len);

  fu_byte_array_align_up(st_hdr, FU_FIRMWARE_ALIGNMENT_4, 0x0);

  /* success */

  return g_steal_pointer(&st_hdr);

}

static gboolean

fu_fdt_firmware_build(FuFirmware *firmware, XbNode *n, GError **error)

{

  FuFdtFirmware *self = FU_FDT_FIRMWARE(firmware);

  FuFdtFirmwarePrivate *priv = GET_PRIVATE(self);

  guint64 tmp;

  /* optional properties */

  tmp = xb_node_query_text_as_uint(n, "cpuid", NULL);

  if (tmp != G_MAXUINT64 && tmp <= G_MAXUINT32)

    priv->cpuid = tmp;

  /* success */

  return TRUE;

}

static void

fu_fdt_firmware_init(FuFdtFirmware *self)

{

  g_type_ensure(FU_TYPE_FDT_IMAGE);

  fu_firmware_add_flag(FU_FIRMWARE(self), FU_FIRMWARE_FLAG_HAS_VID_PID);

}

static void

fu_fdt_firmware_class_init(FuFdtFirmwareClass *klass)

{

  FuFirmwareClass *firmware_class = FU_FIRMWARE_CLASS(klass);

  firmware_class->validate = fu_fdt_firmware_validate;

  firmware_class->export = fu_fdt_firmware_export;

  firmware_class->parse = fu_fdt_firmware_parse;

  firmware_class->write = fu_fdt_firmware_write;

  firmware_class->build = fu_fdt_firmware_build;

}

/**

 * fu_fdt_firmware_new:

 *

 * Creates a new #FuFirmware of sub type FDT

 *

 * Since: 1.8.2

 **/

FuFirmware *

fu_fdt_firmware_new(void)

{

  return FU_FIRMWARE(g_object_new(FU_TYPE_FDT_FIRMWARE, NULL));

}