OpenWrt – Rev 4
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/*
* Copyright (C) 2012 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> /* for unlink() */
#include <libgen.h>
#include <getopt.h> /* for getopt() */
#include <stdarg.h>
#include <errno.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#define MAX_MODEL_LEN 20
#define MAX_SIGNATURE_LEN 30
#define MAX_REGION_LEN 4
#define MAX_VERSION_LEN 12
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
struct file_info {
char *file_name; /* name of the file */
uint32_t file_size; /* length of the file */
uint32_t write_size;
};
struct img_header {
uint32_t checksum;
uint32_t image_size;
uint32_t kernel_size;
char model[MAX_MODEL_LEN];
char signature[MAX_SIGNATURE_LEN];
char region[MAX_REGION_LEN];
char version[MAX_VERSION_LEN];
unsigned char header_len;
unsigned char is_tgz;
unsigned char pad[4];
} __attribute__ ((packed));
/*
* Globals
*/
static char *ofname;
static char *progname;
static char *model;
static char *signature;
static char *region = "DEF";
static char *version;
static struct file_info kernel_info;
static struct file_info rootfs_info;
static uint32_t kernel_size;
static uint32_t image_size;
static int combined;
/*
* Message macros
*/
#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 DBG(fmt, ...) do { \
fprintf(stderr, "[%s] " fmt "\n", progname, ## __VA_ARGS__ ); \
} while (0)
static void usage(int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream,
"\n"
"Options:\n"
" -k <file> read kernel image from the file <file>\n"
" -c use the kernel image as a combined image\n"
" -M <model> set model to <model>\n"
" -o <file> write output to the file <file>\n"
" -r <file> read rootfs image from the file <file>\n"
" -S <signature> set image signature to <signature>\n"
" -R <region> set image region to <region>\n"
" -V <version> set image version to <version>\n"
" -I <size> set image size to <size>\n"
" -K <size> set kernel size to <size>\n"
" -h show this screen\n"
);
exit(status);
}
int
str2u32(char *arg, uint32_t *val)
{
char *err = NULL;
uint32_t t;
errno=0;
t = strtoul(arg, &err, 0);
if (errno || (err==arg) || ((err != NULL) && *err)) {
return -1;
}
*val = t;
return 0;
}
static int get_file_stat(struct file_info *fdata)
{
struct stat st;
int res;
if (fdata->file_name == NULL)
return 0;
res = stat(fdata->file_name, &st);
if (res){
ERRS("stat failed on %s", fdata->file_name);
return res;
}
fdata->file_size = st.st_size;
fdata->write_size = fdata->file_size;
return 0;
}
static int read_to_buf(struct file_info *fdata, char *buf)
{
FILE *f;
int ret = EXIT_FAILURE;
f = fopen(fdata->file_name, "r");
if (f == NULL) {
ERRS("could not open \"%s\" for reading", fdata->file_name);
goto out;
}
errno = 0;
fread(buf, fdata->file_size, 1, f);
if (errno != 0) {
ERRS("unable to read from file \"%s\"", fdata->file_name);
goto out_close;
}
ret = EXIT_SUCCESS;
out_close:
fclose(f);
out:
return ret;
}
static int check_options(void)
{
int ret;
#define CHKSTR(_name, _msg) \
do { \
if (_name == NULL) { \
ERR("no %s specified", _msg); \
return -1; \
} \
} while (0)
#define CHKSTRLEN(_name, _msg) \
do { \
int field_len; \
CHKSTR(_name, _msg); \
field_len = FIELD_SIZEOF(struct img_header, _name) - 1; \
if (strlen(_name) > field_len) { \
ERR("%s is too long, max length is %d", \
_msg, field_len); \
return -1; \
} \
} while (0)
CHKSTRLEN(model, "model");
CHKSTRLEN(signature, "signature");
CHKSTRLEN(region, "region");
CHKSTRLEN(version, "version");
CHKSTR(ofname, "output file");
CHKSTR(kernel_info.file_name, "kernel image");
ret = get_file_stat(&kernel_info);
if (ret)
return ret;
if (combined) {
if (!kernel_size) {
ERR("kernel size must be specified for combined images");
return -1; \
}
if (!image_size)
image_size = kernel_info.file_size;
if (kernel_info.file_size > image_size) {
ERR("kernel image is too big");
return -1;
}
kernel_info.write_size = image_size;
} else {
CHKSTR(rootfs_info.file_name, "rootfs image");
ret = get_file_stat(&rootfs_info);
if (ret)
return ret;
if (kernel_size) {
/* override kernel size */
kernel_info.write_size = kernel_size;
}
if (image_size) {
if (image_size < kernel_info.write_size)
kernel_info.write_size = image_size;
/* override rootfs size */
rootfs_info.write_size = image_size - kernel_info.write_size;
}
if (kernel_info.file_size > kernel_info.write_size) {
ERR("kernel image is too big");
return -1;
}
if (rootfs_info.file_size > rootfs_info.write_size) {
ERR("rootfs image is too big");
return -1;
}
}
return 0;
}
static int write_fw(char *data, int len)
{
FILE *f;
int ret = EXIT_FAILURE;
f = fopen(ofname, "w");
if (f == NULL) {
ERRS("could not open \"%s\" for writing", ofname);
goto out;
}
errno = 0;
fwrite(data, len, 1, f);
if (errno) {
ERRS("unable to write output file");
goto out_flush;
}
DBG("firmware file \"%s\" completed", ofname);
ret = EXIT_SUCCESS;
out_flush:
fflush(f);
fclose(f);
if (ret != EXIT_SUCCESS) {
unlink(ofname);
}
out:
return ret;
}
static uint32_t get_csum(unsigned char *p, uint32_t len)
{
uint32_t csum = 0;
while (len--)
csum += *p++;
return csum;
}
static int build_fw(void)
{
int buflen;
char *buf;
char *p;
uint32_t csum;
struct img_header *hdr;
int ret = EXIT_FAILURE;
buflen = sizeof(struct img_header) +
kernel_info.write_size + rootfs_info.write_size;
buf = malloc(buflen);
if (!buf) {
ERR("no memory for buffer\n");
goto out;
}
memset(buf, 0, buflen);
p = buf + sizeof(struct img_header);
/* read kernel data */
ret = read_to_buf(&kernel_info, p);
if (ret)
goto out_free_buf;
if (!combined) {
p += kernel_info.write_size;
/* read rootfs data */
ret = read_to_buf(&rootfs_info, p);
if (ret)
goto out_free_buf;
}
csum = get_csum((unsigned char *)(buf + sizeof(struct img_header)),
buflen - sizeof(struct img_header));
/* fill firmware header */
hdr = (struct img_header *) buf;
hdr->checksum = htonl(csum);
hdr->image_size = htonl(buflen - sizeof(struct img_header));
if (!combined)
hdr->kernel_size = htonl(kernel_info.write_size);
else
hdr->kernel_size = htonl(kernel_size);
hdr->header_len = sizeof(struct img_header);
strncpy(hdr->model, model, sizeof(hdr->model));
strncpy(hdr->signature, signature, sizeof(hdr->signature));
strncpy(hdr->version, version, sizeof(hdr->version));
strncpy(hdr->region, region, sizeof(hdr->region));
ret = write_fw(buf, buflen);
if (ret)
goto out_free_buf;
ret = EXIT_SUCCESS;
out_free_buf:
free(buf);
out:
return ret;
}
int main(int argc, char *argv[])
{
int ret = EXIT_FAILURE;
progname = basename(argv[0]);
while (1) {
int c;
c = getopt(argc, argv, "M:S:V:R:k:K:I:r:o:hc");
if (c == -1)
break;
switch (c) {
case 'M':
model = optarg;
break;
case 'S':
signature = optarg;
break;
case 'V':
version = optarg;
break;
case 'R':
region = optarg;
break;
case 'k':
kernel_info.file_name = optarg;
break;
case 'K':
if (str2u32(optarg, &kernel_size)) {
ERR("%s is invalid '%s'",
"kernel size", optarg);
goto out;
}
break;
case 'I':
if (str2u32(optarg, &image_size)) {
ERR("%s is invalid '%s'",
"image size", optarg);
goto out;
}
break;
case 'r':
rootfs_info.file_name = optarg;
break;
case 'c':
combined = 1;
break;
case 'o':
ofname = optarg;
break;
case 'h':
usage(EXIT_SUCCESS);
break;
default:
usage(EXIT_FAILURE);
break;
}
}
ret = check_options();
if (ret)
goto out;
ret = build_fw();
out:
return ret;
}