Function parse_vbt

util/intelvbttool/intelvbttool.c:733–794

Returns a new fileobject containing a valid VBT */

/* Returns a new fileobject containing a valid VBT */
static void parse_vbt(const struct fileobject *fo,
		      struct fileobject **vbt)
{
	*vbt = NULL;

	if (fo->size < sizeof(struct vbt_header)) {
		printerr("image is too small\n");
		return;
	}

	const struct vbt_header *head =
	    (const struct vbt_header *)fo->data;

	if (memcmp(head->signature, "$VBT", 4) != 0) {
		printerr("invalid VBT signature\n");
		return;
	}

	if (!head->vbt_size || head->vbt_size > fo->size) {
		printerr("invalid VBT size\n");
		return;
	}

	if (!head->bdb_offset ||
	    head->bdb_offset > fo->size - sizeof(struct bdb_header)) {
		printerr("invalid BDB offset\n");
		return;
	}

	if (!head->header_size || head->header_size > fo->size) {
		printerr("invalid header size\n");
		return;
	}

	const struct bdb_header *const bdb_head =
	    (const struct bdb_header *)((const u8 *)head + head->bdb_offset);
	if (memcmp(bdb_head->signature, "BIOS_DATA_BLOCK ", 16) != 0) {
		printerr("invalid BDB signature\n");
		return;
	}

	if (!bdb_head->header_size || bdb_head->header_size > fo->size) {
		printerr("invalid BDB header size\n");
		return;
	}

	/* Duplicate fo as caller is owner and remalloc frees the object */
	struct fileobject *dupfo = malloc_fo_sub(fo, 0);
	if (!dupfo) {
		printerr("malloc failed\n");
		return;
	}

	struct fileobject *newfo = remalloc_fo(dupfo, head->vbt_size);
	if (!newfo) {
		printerr("remalloc failed\n");
		free_fo(dupfo);
		return;