package/mtd/src/trx.c

   1 /*
   2  * trx.c
   3  *
   4  * Copyright (C) 2005 Mike Baker
   5  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20  */
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <sys/mman.h>
  28 #include <sys/stat.h>
  29 #include <string.h>
  30
  31 #include <sys/ioctl.h>
  32 #include "mtd-api.h"
  33 #include "mtd.h"
  34
  35 #define TRX_MAGIC       0x30524448      /* "HDR0" */
  36 struct trx_header {
  37         unsigned magic;         /* "HDR0" */
  38         unsigned len;           /* Length of file including header */
  39         unsigned crc32;         /* 32-bit CRC from flag_version to end of file */
  40         unsigned flag_version;  /* 0:15 flags, 16:31 version */
  41         unsigned offsets[3];    /* Offsets of partitions from start of header */
  42 };
  43
  44 static unsigned long *crc32 = NULL;
  45
  46 static void init_crc32()
  47 {
  48         unsigned long crc;
  49         unsigned long poly = 0xEDB88320L;
  50         int n, bit;
  51
  52         if (crc32)
  53                 return;
  54
  55         crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long));
  56         if (!crc32) {
  57                 perror("malloc");
  58                 exit(1);
  59         }
  60
  61         for (n = 0; n < 256; n++) {
  62                 crc = (unsigned long) n;
  63                 for (bit = 0; bit < 8; bit++)
  64                         crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
  65                 crc32[n] = crc;
  66         }
  67 }
  68
  69 static unsigned int crc32buf(char *buf, size_t len)
  70 {
  71         unsigned int crc = 0xFFFFFFFF;
  72         for (; len; len--, buf++)
  73                 crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
  74         return crc;
  75 }
  76
  77 int
  78 trx_fixup(int fd, const char *name)
  79 {
  80         struct mtd_info_user mtdInfo;
  81         unsigned long len;
  82         struct trx_header *trx;
  83         void *ptr, *scan;
  84         int bfd;
  85
  86         if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) {
  87                 fprintf(stderr, "Failed to get mtd info\n");
  88                 goto err;
  89         }
  90
  91         len = mtdInfo.size;
  92         if (mtdInfo.size <= 0) {
  93                 fprintf(stderr, "Invalid MTD device size\n");
  94                 goto err;
  95         }
  96
  97         bfd = mtd_open(name, true);
  98         ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0);
  99         if (!ptr || (ptr == (void *) -1)) {
 100                 perror("mmap");
 101                 goto err1;
 102         }
 103
 104         trx = ptr;
 105         if (trx->magic != TRX_MAGIC) {
 106                 fprintf(stderr, "TRX header not found\n");
 107                 goto err;
 108         }
 109
 110         init_crc32();
 111         scan = ptr + offsetof(struct trx_header, flag_version);
 112         trx->crc32 = crc32buf(scan, trx->len - (scan - ptr));
 113         msync(ptr, sizeof(struct trx_header), MS_SYNC|MS_INVALIDATE);
 114         munmap(ptr, len);
 115         close(bfd);
 116         return 0;
 117
 118 err1:
 119         close(bfd);
 120 err:
 121         fprintf(stderr, "Error fixing up TRX header\n");
 122         return -1;
 123 }
 124
 125 int
 126 trx_check(int imagefd, const char *mtd, char *buf, int *len)
 127 {
 128         const struct trx_header *trx = (const struct trx_header *) buf;
 129         int fd;
 130
 131         if (strcmp(mtd, "linux") != 0)
 132                 return 1;
 133
 134         *len = read(imagefd, buf, 32);
 135         if (*len < 32) {
 136                 fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len);
 137                 return 0;
 138         }
 139
 140         if (trx->magic != TRX_MAGIC || trx->len < sizeof(struct trx_header)) {
 141                 if (quiet < 2) {
 142                         fprintf(stderr, "Bad trx header\n");
 143                         fprintf(stderr, "This is not the correct file format; refusing to flash.\n"
 144                                         "Please specify the correct file or use -f to force.\n");
 145                 }
 146                 return 0;
 147         }
 148
 149         /* check if image fits to mtd device */
 150         fd = mtd_check_open(mtd);
 151         if(fd < 0) {
 152                 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 153                 exit(1);
 154         }
 155
 156         if(mtdsize < trx->len) {
 157                 fprintf(stderr, "Image too big for partition: %s\n", mtd);
 158                 close(fd);
 159                 return 0;
 160         }
 161
 162         close(fd);
 163         return 1;
 164 }
 165