OpenWrt – Rev 4
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/*
*
* Copyright (C) 2012 OpenWrt.org
* Copyright (C) 2012 Mikko Hissa <mikko.hissa@uta.fi>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <libgen.h>
#include <errno.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "md5.h"
#define HDR_LEN 0x60
#define BUF_SIZE 0x200
#define VERSION_SIZE 0x10
#define MD5_SIZE 0x10
#define PAD_SIZE 0x20
#define DEFAULT_BLOCK_SIZE 65535
#define DEFAULT_HEAD_VALUE 0x0
#define DEFAULT_VERSION "123"
#define DEFAULT_MAGIC 0x12345678
typedef struct {
uint32_t head;
uint32_t vendor_id;
uint32_t product_id;
uint8_t version[VERSION_SIZE];
uint32_t firmware_type;
uint32_t filesize;
uint32_t zero;
uint8_t md5sum[MD5_SIZE];
uint8_t pad[PAD_SIZE];
uint32_t chksum;
uint32_t magic;
} img_header;
typedef struct {
uint8_t id;
char * name;
} firmware_type;
typedef enum {
NONE, ENCODE, DECODE
} op_mode;
static firmware_type FIRMWARE_TYPES[] = {
{ 0x01, "bootloader" },
{ 0x02, "kernel" },
{ 0x03, "kernelapp" },
{ 0x04, "apps" },
/* The types below this line vary by manufacturer */
{ 0x05, "littleapps (D-Link)/factoryapps (EnGenius)" },
{ 0x06, "sounds (D-Link)/littleapps (EnGenius)" },
{ 0x07, "userconfig (D-Link)/appdata (EnGenius)" },
{ 0x08, "userconfig (EnGenius)"},
{ 0x09, "odmapps (EnGenius)"},
{ 0x0a, "factoryapps (D-Link)" },
{ 0x0b, "odmapps (D-Link)" },
{ 0x0c, "langpack (D-Link)" }
};
static long get_file_size(const char *filename)
{
FILE *fp_file;
long result;
fp_file = fopen(filename, "r");
if (!fp_file)
return -1;
fseek(fp_file, 0, SEEK_END);
result = ftell(fp_file);
fclose(fp_file);
return result;
}
static int header_checksum(void *data, int len)
{
int i;
int sum;
sum = 0;
if (data != NULL && len >= 0) {
for (i = 0; i < len; ++i)
sum += *(unsigned char *) (data + i);
return sum;
}
return -1;
}
static int md5_file(const char *filename, uint8_t *dst)
{
FILE *fp_src;
MD5_CTX ctx;
char buf[BUF_SIZE];
size_t bytes_read;
MD5_Init(&ctx);
fp_src = fopen(filename, "r+b");
if (!fp_src) {
return -1;
}
while (!feof(fp_src)) {
bytes_read = fread(&buf, 1, BUF_SIZE, fp_src);
MD5_Update(&ctx, &buf, bytes_read);
}
fclose(fp_src);
MD5_Final(dst, &ctx);
return 0;
}
static int encode_image(const char *input_file_name,
const char *output_file_name, img_header *header, int block_size)
{
char buf[BUF_SIZE];
size_t bytes_read;
size_t pad_len = 0;
size_t bytes_avail;
FILE *fp_input;
FILE *fp_output;
int i;
long magic;
fp_input = fopen(input_file_name, "r+b");
if (!fp_input) {
fprintf(stderr, "Cannot open %s !!\n", input_file_name);
return -1;
}
fp_output = fopen(output_file_name, "w+b");
if (!fp_output) {
fprintf(stderr, "Cannot open %s !!\n", output_file_name);
fclose(fp_input);
return -1;
}
header->filesize = get_file_size(input_file_name);
if (!header->filesize) {
fprintf(stderr, "File %s open/size error!\n", input_file_name);
fclose(fp_input);
fclose(fp_output);
return -1;
}
/*
* Zero padding
*/
if (block_size > 0) {
pad_len = block_size - (header->filesize % block_size);
}
if (md5_file(input_file_name, (uint8_t *) &header->md5sum) < 0) {
fprintf(stderr, "MD5 failed on file %s\n", input_file_name);
fclose(fp_input);
fclose(fp_output);
return -1;
}
header->zero = 0;
header->chksum = header_checksum(header, HDR_LEN);
header->head = htonl(header->head);
header->vendor_id = htonl(header->vendor_id);
header->product_id = htonl(header->product_id);
header->firmware_type = htonl(header->firmware_type);
header->filesize = htonl(header->filesize);
header->chksum = htonl(header->chksum);
magic = header->magic;
header->magic = htonl(header->magic);
fwrite(header, HDR_LEN, 1, fp_output);
while (!feof(fp_input) || pad_len > 0) {
if (!feof(fp_input))
bytes_read = fread(&buf, 1, BUF_SIZE, fp_input);
else
bytes_read = 0;
/*
* No more bytes read, start padding
*/
if (bytes_read < BUF_SIZE && pad_len > 0) {
bytes_avail = BUF_SIZE - bytes_read;
memset( &buf[bytes_read], 0, bytes_avail);
bytes_read += bytes_avail < pad_len ? bytes_avail : pad_len;
pad_len -= bytes_avail < pad_len ? bytes_avail : pad_len;
}
for (i = 0; i < bytes_read; i++)
buf[i] ^= magic >> (i % 8) & 0xff;
fwrite(&buf, bytes_read, 1, fp_output);
}
fclose(fp_input);
fclose(fp_output);
return 1;
}
int decode_image(const char *input_file_name, const char *output_file_name)
{
img_header header;
char buf[BUF_SIZE];
FILE *fp_input;
FILE *fp_output;
unsigned int i;
size_t bytes_read;
size_t bytes_written;
fp_input = fopen(input_file_name, "r+b");
if (!fp_input) {
fprintf(stderr, "Cannot open %s !!\n", input_file_name);
fclose(fp_input);
return -1;
}
fp_output = fopen(output_file_name, "w+b");
if (!fp_output) {
fprintf(stderr, "Cannot open %s !!\n", output_file_name);
fclose(fp_output);
return -1;
}
if (fread(&header, 1, HDR_LEN, fp_input) != HDR_LEN) {
fprintf(stderr, "Incorrect header size!!");
fclose(fp_input);
fclose(fp_output);
return -1;
}
header.head = ntohl(header.head);
header.vendor_id = ntohl(header.vendor_id);
header.product_id = ntohl(header.product_id);
header.firmware_type = ntohl(header.firmware_type);
header.filesize = ntohl(header.filesize);
header.chksum = ntohl(header.chksum);
header.magic = ntohl(header.magic);
bytes_written = 0;
while (!feof(fp_input)) {
bytes_read = fread(&buf, 1, BUF_SIZE, fp_input);
for (i = 0; i < bytes_read; i++)
buf[i] ^= header.magic >> (i % 8) & 0xff;
/*
* Handle padded source file
*/
if (bytes_written + bytes_read > header.filesize) {
bytes_read = header.filesize - bytes_written;
if (bytes_read > 0)
fwrite(&buf, bytes_read, 1, fp_output);
break;
}
fwrite(&buf, bytes_read, 1, fp_output);
bytes_written += bytes_read;
}
fclose(fp_input);
fclose(fp_output);
return 1;
}
static void usage(const char *progname, int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
int i;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream, "\n"
"Options:\n"
" -e <file> encode image file <file>\n"
" -d <file> decode image file <file>\n"
" -o <file> write output to the file <file>\n"
" -t <type> set image type to <type>\n"
" valid image <type> values:\n");
for (i = 0; i < sizeof(FIRMWARE_TYPES) / sizeof(firmware_type); i++) {
fprintf(stream, " %-5i= %s\n", FIRMWARE_TYPES[i].id,
FIRMWARE_TYPES[i].name);
}
fprintf(stream, " -v <version> set image version to <version>\n"
" -r <vendor> set image vendor id to <vendor>\n"
" -p <product> set image product id to <product>\n"
" -m <magic> set encoding magic <magic>\n"
" -z enable image padding to <blocksize>\n"
" -b <blocksize> set image <blocksize>, defaults to %u\n"
" -h show this screen\n", DEFAULT_BLOCK_SIZE);
exit(status);
}
int main(int argc, char *argv[])
{
int opt;
char *input_file, *output_file, *progname = NULL;
op_mode mode = NONE;
int tmp, i, pad = 0;
int block_size;
img_header header;
block_size = DEFAULT_BLOCK_SIZE;
progname = basename(argv[0]);
memset(&header, 0, sizeof( img_header ));
header.magic = DEFAULT_MAGIC;
header.head = DEFAULT_HEAD_VALUE;
strncpy( (char*)&header.version, DEFAULT_VERSION, VERSION_SIZE - 1);
while ((opt = getopt(argc, argv, ":o:e:d:t:v:r:p:m:b:h?z")) != -1) {
switch (opt) {
case 'e':
input_file = optarg;
mode = ENCODE;
break;
case 'd':
input_file = optarg;
mode = DECODE;
break;
case 'o':
output_file = optarg;
break;
case 't':
tmp = strtol(optarg, 0, 10);
for (i = 0; i < sizeof(FIRMWARE_TYPES) / sizeof(firmware_type);
i++) {
if (FIRMWARE_TYPES[i].id == tmp) {
header.firmware_type = FIRMWARE_TYPES[i].id;
break;
}
}
if (header.firmware_type == 0) {
fprintf(stderr, "Invalid firmware type \"0\"!\n");
usage(progname, EXIT_FAILURE);
}
break;
case 'v':
strncpy( (char*)&header.version, optarg,
VERSION_SIZE - 1);
break;
case 'r':
header.vendor_id = strtol(optarg, 0, 0);
break;
case 'p':
header.product_id = strtol(optarg, 0, 0);
break;
case 'm':
header.magic = strtoul(optarg, 0, 16);
break;
case 'z':
pad = 1;
break;
case 'b':
block_size = strtol(optarg, 0, 10);
break;
case 'h':
usage(progname, EXIT_SUCCESS);
break;
case ':':
fprintf(stderr, "Option -%c requires an operand\n", optopt);
usage(progname, EXIT_FAILURE);
break;
case '?':
fprintf(stderr, "Unrecognized option: -%c\n", optopt);
usage(progname, EXIT_FAILURE);
break;
default:
usage(progname, EXIT_FAILURE);
break;
}
}
/* Check required arguments */
if (mode == NONE) {
fprintf(stderr, "A mode must be defined\n");
usage(progname, EXIT_FAILURE);
}
if (input_file == NULL || output_file == NULL) {
fprintf(stderr, "Input and output files must be defined\n");
usage(progname, EXIT_FAILURE);
}
if (mode == DECODE) {
if (decode_image(input_file, output_file) < 0)
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
if (header.firmware_type == 0) {
fprintf(stderr, "Firmware type must be defined\n");
usage(progname, EXIT_FAILURE);
}
if (header.vendor_id == 0 || header.product_id == 0) {
fprintf(stderr, "Vendor ID and Product ID must be defined and non-zero\n");
usage(progname, EXIT_FAILURE);
}
if (encode_image(input_file, output_file, &header, pad ? block_size : 0) < 0)
return EXIT_FAILURE;
return EXIT_SUCCESS;
}