openwrtv3/package/mtd/src/trx.c

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/*
* trx.c
*
* Copyright (C) 2005 Mike Baker
* Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <string.h>
#include <sys/ioctl.h>
#include "mtd-api.h"
#include "mtd.h"
#define TRX_MAGIC 0x30524448 /* "HDR0" */
struct trx_header {
unsigned magic; /* "HDR0" */
unsigned len; /* Length of file including header */
unsigned crc32; /* 32-bit CRC from flag_version to end of file */
unsigned flag_version; /* 0:15 flags, 16:31 version */
unsigned offsets[3]; /* Offsets of partitions from start of header */
};
static unsigned long *crc32 = NULL;
static void init_crc32()
{
unsigned long crc;
unsigned long poly = 0xEDB88320L;
int n, bit;
if (crc32)
return;
crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long));
if (!crc32) {
perror("malloc");
exit(1);
}
for (n = 0; n < 256; n++) {
crc = (unsigned long) n;
for (bit = 0; bit < 8; bit++)
crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
crc32[n] = crc;
}
}
static unsigned int crc32buf(char *buf, size_t len)
{
unsigned int crc = 0xFFFFFFFF;
for (; len; len--, buf++)
crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
return crc;
}
int
trx_fixup(int fd, const char *name)
{
struct mtd_info_user mtdInfo;
unsigned long len;
struct trx_header *trx;
void *ptr, *scan;
int bfd;
if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) {
fprintf(stderr, "Failed to get mtd info\n");
goto err;
}
len = mtdInfo.size;
if (mtdInfo.size <= 0) {
fprintf(stderr, "Invalid MTD device size\n");
goto err;
}
bfd = mtd_open(name, true);
ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0);
if (!ptr || (ptr == (void *) -1)) {
perror("mmap");
goto err1;
}
trx = ptr;
if (trx->magic != TRX_MAGIC) {
fprintf(stderr, "TRX header not found\n");
goto err;
}
init_crc32();
scan = ptr + offsetof(struct trx_header, flag_version);
trx->crc32 = crc32buf(scan, trx->len - (scan - ptr));
msync(ptr, sizeof(struct trx_header), MS_SYNC|MS_INVALIDATE);
munmap(ptr, len);
close(bfd);
return 0;
err1:
close(bfd);
err:
fprintf(stderr, "Error fixing up TRX header\n");
return -1;
}
int
trx_check(int imagefd, const char *mtd, char *buf, int *len)
{
const struct trx_header *trx = (const struct trx_header *) buf;
int fd;
if (strcmp(mtd, "linux") != 0)
return 1;
*len = read(imagefd, buf, 32);
if (*len < 32) {
fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len);
return 0;
}
if (trx->magic != TRX_MAGIC || trx->len < sizeof(struct trx_header)) {
if (quiet < 2) {
fprintf(stderr, "Bad trx header\n");
fprintf(stderr, "This is not the correct file format; refusing to flash.\n"
"Please specify the correct file or use -f to force.\n");
}
return 0;
}
/* check if image fits to mtd device */
fd = mtd_check_open(mtd);
if(fd < 0) {
fprintf(stderr, "Could not open mtd device: %s\n", mtd);
exit(1);
}
if(mtdsize < trx->len) {
fprintf(stderr, "Image too big for partition: %s\n", mtd);
close(fd);
return 0;
}
close(fd);
return 1;
}