1// SPDX-License-Identifier: MIT
2/*
3 * Copyright (C) 2016 The Android Open Source Project
4 */
5
6#include "avb_kernel_cmdline_descriptor.h"
7#include "avb_util.h"
8
9bool avb_kernel_cmdline_descriptor_validate_and_byteswap(
10    const AvbKernelCmdlineDescriptor* src, AvbKernelCmdlineDescriptor* dest) {
11  uint64_t expected_size;
12
13  avb_memcpy(dest, src, sizeof(AvbKernelCmdlineDescriptor));
14
15  if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src,
16                                            (AvbDescriptor*)dest))
17    return false;
18
19  if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE) {
20    avb_error("Invalid tag for kernel cmdline descriptor.\n");
21    return false;
22  }
23
24  dest->flags = avb_be32toh(dest->flags);
25  dest->kernel_cmdline_length = avb_be32toh(dest->kernel_cmdline_length);
26
27  /* Check that kernel_cmdline is fully contained. */
28  expected_size = sizeof(AvbKernelCmdlineDescriptor) - sizeof(AvbDescriptor);
29  if (!avb_safe_add_to(&expected_size, dest->kernel_cmdline_length)) {
30    avb_error("Overflow while adding up sizes.\n");
31    return false;
32  }
33  if (expected_size > dest->parent_descriptor.num_bytes_following) {
34    avb_error("Descriptor payload size overflow.\n");
35    return false;
36  }
37
38  return true;
39}
40