| /* |
| * Copyright 2016 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <getopt.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include "futility.h" |
| |
| enum { |
| OPT_HELP = 1000, |
| OPT_OFFSET, |
| }; |
| |
| static const struct option long_opts[] = { |
| {"help", 0, 0, OPT_HELP}, |
| {"offset", 1, 0, OPT_OFFSET}, |
| {NULL, 0, NULL, 0}, |
| }; |
| |
| static void print_help(int argc, char *argv[]) |
| { |
| printf("\nUsage: " MYNAME " %s FILE [OPTIONS]\n", argv[0]); |
| printf("\nOptions:\n"); |
| printf(" --offset <offset> Offset of cache within FILE\n"); |
| printf("\n"); |
| } |
| |
| struct mrc_cache { |
| uint32_t signature; |
| uint32_t size; |
| uint32_t checksum; |
| uint32_t version; |
| uint8_t data[0]; |
| } __attribute__((packed)); |
| |
| #define MRC_DATA_SIGNATURE (('M'<<0)|('R'<<8)|('C'<<16)|('D'<<24)) |
| |
| unsigned long compute_ip_checksum(void *addr, unsigned long length) |
| { |
| uint8_t *ptr; |
| volatile union { |
| uint8_t byte[2]; |
| uint16_t word; |
| } value; |
| unsigned long sum; |
| unsigned long i; |
| /* In the most straight forward way possible, |
| * compute an ip style checksum. |
| */ |
| sum = 0; |
| ptr = addr; |
| for(i = 0; i < length; i++) { |
| unsigned long v; |
| v = ptr[i]; |
| if (i & 1) { |
| v <<= 8; |
| } |
| /* Add the new value */ |
| sum += v; |
| /* Wrap around the carry */ |
| if (sum > 0xFFFF) { |
| sum = (sum + (sum >> 16)) & 0xFFFF; |
| } |
| } |
| value.byte[0] = sum & 0xff; |
| value.byte[1] = (sum >> 8) & 0xff; |
| return (~value.word) & 0xFFFF; |
| } |
| |
| static int verify_checksum(struct mrc_cache *cache, unsigned long cache_len) |
| { |
| uint32_t checksum; |
| if (cache->signature != MRC_DATA_SIGNATURE) { |
| fprintf(stderr, "MRC signature mismatch\n"); |
| return 1; |
| } |
| |
| fprintf(stderr, "MRC signature match.. successful\n"); |
| |
| if (cache->size > cache_len) { |
| fprintf(stderr, "MRC cache size overflow\n"); |
| return 1; |
| } |
| |
| checksum = compute_ip_checksum((void *)&cache->data[0], cache->size); |
| |
| if (checksum != cache->checksum) { |
| fprintf(stderr, "MRC checksum mismatch\n"); |
| return 1; |
| } |
| |
| fprintf(stderr, "MRC checksum.. verified!\n"); |
| return 0; |
| } |
| |
| static int do_validate_rec_mrc(int argc, char *argv[]) |
| { |
| char *infile = NULL; |
| int parse_error = 0; |
| int fd, i, ret = 1; |
| uint32_t file_size; |
| uint8_t *buff; |
| uint32_t offset = 0; |
| char *e; |
| |
| while (((i = getopt_long(argc, argv, ":", long_opts, NULL)) != -1) && |
| !parse_error) { |
| switch (i) { |
| case OPT_HELP: |
| print_help(argc, argv); |
| return 0; |
| case OPT_OFFSET: |
| offset = strtoul(optarg, &e, 0); |
| if (!*optarg || (e && *e)) { |
| fprintf(stderr, "Invalid --offset\n"); |
| parse_error = 1; |
| } |
| break; |
| default: |
| case '?': |
| parse_error = 1; |
| break; |
| } |
| } |
| |
| if (parse_error) { |
| print_help(argc, argv); |
| return 1; |
| } |
| |
| if ((argc - optind) < 1) { |
| fprintf(stderr, "You must specify an input FILE!\n"); |
| print_help(argc, argv); |
| return 1; |
| } else if ((argc - optind) != 1) { |
| fprintf(stderr, "Unexpected arguments!\n"); |
| print_help(argc, argv); |
| return 1; |
| } |
| |
| infile = argv[optind++]; |
| |
| fd = open(infile, O_RDONLY); |
| if (fd < 0) { |
| fprintf(stderr, "Cannot open %s:%s\n", infile, strerror(errno)); |
| return 1; |
| } |
| |
| if (futil_map_file(fd, MAP_RO, &buff, &file_size) != FILE_ERR_NONE) { |
| fprintf(stderr, "Cannot map file %s\n", infile); |
| close(fd); |
| return 1; |
| } |
| |
| if (file_size > offset) |
| ret = verify_checksum((struct mrc_cache *)(buff + offset), |
| file_size - offset); |
| else |
| fprintf(stderr, "Offset greater than file size: offset=0x%x, " |
| "file size=0x%x\n", offset, file_size); |
| |
| if (futil_unmap_file(fd, MAP_RO, buff, file_size) != FILE_ERR_NONE) { |
| fprintf(stderr, "Failed to unmap file %s\n", infile); |
| ret = 1; |
| } |
| |
| close(fd); |
| return ret; |
| } |
| |
| DECLARE_FUTIL_COMMAND(validate_rec_mrc, do_validate_rec_mrc, VBOOT_VERSION_ALL, |
| "Validates content of Recovery MRC cache"); |