OpenWrt – Rev 1
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/*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
*
* 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 <stdint.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <getopt.h>
#include <stdarg.h>
#include <errno.h>
#include <sys/stat.h>
#include "md5.h"
#define ERR(fmt, ...) do { \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt "\n", \
progname, ## __VA_ARGS__ ); \
} while (0)
#define ERRS(fmt, ...) do { \
int save = errno; \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt ", %s\n", \
progname, ## __VA_ARGS__, strerror(save)); \
} while (0)
#define WRG_MAGIC 0x20040220
struct wrg_header {
char signature[32];
uint32_t magic1;
uint32_t magic2;
uint32_t size;
uint32_t offset;
char devname[32];
char digest[16];
} __attribute__ ((packed));
static char *progname;
static char *ifname;
static char *ofname;
static char *signature;
static char *dev_name;
static uint32_t offset;
static int big_endian;
void usage(int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream,
"\n"
"Options:\n"
" -b create image in big endian format\n"
" -i <file> read input from the file <file>\n"
" -d <name> set device name to <name>\n"
" -o <file> write output to the file <file>\n"
" -O <offset> set offset to <offset>\n"
" -s <sig> set image signature to <sig>\n"
" -h show this screen\n"
);
exit(status);
}
static void put_u32(void *data, uint32_t val)
{
unsigned char *p = data;
if (big_endian) {
p[0] = (val >> 24) & 0xff;
p[1] = (val >> 16) & 0xff;
p[2] = (val >> 8) & 0xff;
p[3] = val & 0xff;
} else {
p[3] = (val >> 24) & 0xff;
p[2] = (val >> 16) & 0xff;
p[1] = (val >> 8) & 0xff;
p[0] = val & 0xff;
}
}
static void get_digest(struct wrg_header *header, char *data, int size)
{
MD5_CTX ctx;
MD5_Init(&ctx);
MD5_Update(&ctx, (char *)&header->offset, sizeof(header->offset));
MD5_Update(&ctx, (char *)&header->devname, sizeof(header->devname));
MD5_Update(&ctx, data, size);
MD5_Final(header->digest, &ctx);
}
int main(int argc, char *argv[])
{
struct wrg_header *header;
char *buf;
struct stat st;
int buflen;
int err;
int res = EXIT_FAILURE;
FILE *outfile, *infile;
progname = basename(argv[0]);
while ( 1 ) {
int c;
c = getopt(argc, argv, "bd:i:o:s:O:h");
if (c == -1)
break;
switch (c) {
case 'b':
big_endian = 1;
break;
case 'd':
dev_name = optarg;
break;
case 'i':
ifname = optarg;
break;
case 'o':
ofname = optarg;
break;
case 's':
signature = optarg;
break;
case 'O':
offset = strtoul(optarg, NULL, 0);
break;
case 'h':
usage(EXIT_SUCCESS);
break;
default:
usage(EXIT_FAILURE);
break;
}
}
if (signature == NULL) {
ERR("no signature specified");
goto err;
}
if (ifname == NULL) {
ERR("no input file specified");
goto err;
}
if (ofname == NULL) {
ERR("no output file specified");
goto err;
}
if (dev_name == NULL) {
ERR("no device name specified");
goto err;
}
err = stat(ifname, &st);
if (err){
ERRS("stat failed on %s", ifname);
goto err;
}
buflen = st.st_size + sizeof(struct wrg_header);
buf = malloc(buflen);
if (!buf) {
ERR("no memory for buffer\n");
goto err;
}
infile = fopen(ifname, "r");
if (infile == NULL) {
ERRS("could not open \"%s\" for reading", ifname);
goto err_free;
}
errno = 0;
fread(buf + sizeof(struct wrg_header), st.st_size, 1, infile);
if (errno != 0) {
ERRS("unable to read from file %s", ifname);
goto close_in;
}
header = (struct wrg_header *) buf;
memset(header, '\0', sizeof(struct wrg_header));
strncpy(header->signature, signature, sizeof(header->signature));
strncpy(header->devname, dev_name, sizeof(header->signature));
put_u32(&header->magic1, WRG_MAGIC);
put_u32(&header->magic2, WRG_MAGIC);
put_u32(&header->size, st.st_size);
put_u32(&header->offset, offset);
get_digest(header, buf + sizeof(struct wrg_header), st.st_size);
outfile = fopen(ofname, "w");
if (outfile == NULL) {
ERRS("could not open \"%s\" for writing", ofname);
goto close_in;
}
errno = 0;
fwrite(buf, buflen, 1, outfile);
if (errno) {
ERRS("unable to write to file %s", ofname);
goto close_out;
}
fflush(outfile);
res = EXIT_SUCCESS;
close_out:
fclose(outfile);
if (res != EXIT_SUCCESS)
unlink(ofname);
close_in:
fclose(infile);
err_free:
free(buf);
err:
return res;
}