package/mtd/src/imagetag.c

   1 /*
   2  * imagetag.c
   3  *
   4  * Copyright (C) 2005 Mike Baker
   5  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   6  * Copyrigth (C) 2010 Daniel Dickinson <openwrt@cshore.neomailbox.net>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <stddef.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <sys/mman.h>
  29 #include <sys/stat.h>
  30 #include <string.h>
  31 #include <errno.h>
  32
  33 #include <sys/ioctl.h>
  34 #include <mtd/mtd-user.h>
  35 #include <linux/bcm963xx_tag.h>
  36
  37 #include "mtd.h"
  38 #include "crc32.h"
  39
  40 ssize_t pread(int fd, void *buf, size_t count, off_t offset);
  41 ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
  42
  43 #define CRC_START 0xFFFFFFFF
  44
  45 static uint32_t strntoul(char *str, char **endptr, int base, size_t len) {
  46   char *newstr;
  47   uint32_t res = 0;
  48
  49   newstr = calloc(len + 1, sizeof(char));
  50   if (newstr) {
  51         strncpy(newstr, str, len);
  52         res = strtoul(newstr, endptr, base);
  53         free(newstr);
  54   }
  55   return res;
  56 }
  57
  58 uint32_t compute_crc32(uint32_t crc, off_t start, size_t compute_len, int fd)
  59 {
  60         uint8_t readbuf[1024];
  61         ssize_t res;
  62         off_t offset = start;
  63
  64         /* Read a buffer's worth of bytes  */
  65         while (fd && (compute_len >= sizeof(readbuf))) {
  66                 res = pread(fd, readbuf, sizeof(readbuf), offset);
  67                 crc = crc32(crc, readbuf, res);
  68                 compute_len = compute_len - res;
  69                 offset += res;
  70         }
  71
  72         /* Less than buffer-size bytes remains, read compute_len bytes */
  73         if (fd && (compute_len > 0)) {
  74           res = pread(fd, readbuf, compute_len, offset);
  75           crc = crc32(crc, readbuf, res);
  76         }
  77
  78         return crc;
  79 }
  80
  81 int
  82 trx_fixup(int fd, const char *name)
  83 {
  84         struct mtd_info_user mtdInfo;
  85         unsigned long len;
  86         void *ptr, *scan;
  87         int bfd;
  88         struct bcm_tag *tag;
  89         ssize_t res;
  90         uint32_t cfelen, imagelen, imagestart, rootfslen;
  91         uint32_t imagecrc, rootfscrc, headercrc;
  92         uint32_t offset = 0;
  93         cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;
  94
  95
  96         if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) {
  97                 fprintf(stderr, "Failed to get mtd info\n");
  98                 goto err;
  99         }
 100
 101         len = mtdInfo.size;
 102         if (mtdInfo.size <= 0) {
 103                 fprintf(stderr, "Invalid MTD device size\n");
 104                 goto err;
 105         }
 106
 107         bfd = mtd_open(name, true);
 108         ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0);
 109         if (!ptr || (ptr == (void *) -1)) {
 110                 perror("mmap");
 111                 goto err1;
 112         }
 113
 114         tag = (struct bcm_tag *) (ptr);
 115
 116         cfelen = strntoul(&tag->cfe_length[0], NULL, 10, IMAGE_LEN);
 117         if (cfelen) {
 118           fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
 119           exit(1);
 120         }
 121
 122         headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, header_crc), fd);
 123         if (headercrc != *(uint32_t *)(&tag->header_crc)) {
 124                 fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
 125                 exit(1);
 126         }
 127
 128         sprintf(&tag->root_length[0], "%u", 0);
 129         strncpy(&tag->total_length[0], &tag->kernel_length[0], IMAGE_LEN);
 130
 131         imagestart = sizeof(tag);
 132         memcpy(&tag->image_crc, &tag->kernel_crc, sizeof(uint32_t));
 133         memcpy(&tag->fskernel_crc, &tag->kernel_crc, sizeof(uint32_t));
 134         rootfscrc = CRC_START;
 135         memcpy(&tag->rootfs_crc, &rootfscrc, sizeof(uint32_t));
 136         headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, header_crc));
 137         memcpy(&tag->header_crc, &headercrc, sizeof(uint32_t));
 138
 139         msync(ptr, sizeof(struct bcm_tag), MS_SYNC|MS_INVALIDATE);
 140         munmap(ptr, len);
 141         close(bfd);
 142         return 0;
 143
 144 err1:
 145         close(bfd);
 146 err:
 147         fprintf(stderr, "Error fixing up imagetag header\n");
 148         return -1;
 149 }
 150
 151
 152 int
 153 trx_check(int imagefd, const char *mtd, char *buf, int *len)
 154 {
 155     struct bcm_tag *tag = (const struct bcm_tag *) buf;
 156         int fd;
 157         uint32_t headerCRC;
 158         uint32_t imageLen;
 159
 160         if (strcmp(mtd, "linux") != 0)
 161                 return 1;
 162
 163         *len = read(imagefd, buf, sizeof(struct bcm_tag));
 164         if (*len < sizeof(struct bcm_tag)) {
 165                 fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len);
 166                 return 0;
 167         }
 168         headerCRC = crc32buf(buf, offsetof(struct bcm_tag, header_crc));
 169         if (*(uint32_t *)(&tag->header_crc) != headerCRC) {
 170
 171           if (quiet < 2) {
 172                 fprintf(stderr, "Bad header CRC got %08x, calculated %08x\n",
 173                                 *(uint32_t *)(&tag->header_crc), headerCRC);
 174                 fprintf(stderr, "This is not the correct file format; refusing to flash.\n"
 175                                 "Please specify the correct file or use -f to force.\n");
 176           }
 177           return 0;
 178         }
 179
 180         /* check if image fits to mtd device */
 181         fd = mtd_check_open(mtd);
 182         if(fd < 0) {
 183                 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 184                 exit(1);
 185         }
 186
 187         imageLen = strntoul(&tag->total_length[0], NULL, 10, IMAGE_LEN);
 188
 189         if(mtdsize < imageLen) {
 190                 fprintf(stderr, "Image too big for partition: %s\n", mtd);
 191                 close(fd);
 192                 return 0;
 193         }
 194
 195         close(fd);
 196         return 1;
 197 }
 198
 199 int
 200 mtd_fixtrx(const char *mtd, size_t offset)
 201 {
 202         int fd;
 203         struct bcm_tag *tag;
 204         char *buf;
 205         ssize_t res;
 206         size_t block_offset;
 207         uint32_t cfelen, imagelen, imagestart, rootfslen;
 208         uint32_t imagecrc, rootfscrc, headercrc;
 209         cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;
 210
 211         if (quiet < 2)
 212                 fprintf(stderr, "Trying to fix trx header in %s at 0x%x...\n", mtd, offset);
 213
 214         block_offset = offset & ~(erasesize - 1);
 215         offset -= block_offset;
 216
 217         fd = mtd_check_open(mtd);
 218         if(fd < 0) {
 219                 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 220                 exit(1);
 221         }
 222
 223         if (block_offset + erasesize > mtdsize) {
 224                 fprintf(stderr, "Offset too large, device size 0x%x\n", mtdsize);
 225                 exit(1);
 226         }
 227
 228         buf = malloc(erasesize);
 229         if (!buf) {
 230                 perror("malloc");
 231                 exit(1);
 232         }
 233
 234         res = pread(fd, buf, erasesize, block_offset);
 235         if (res != erasesize) {
 236                 perror("pread");
 237                 exit(1);
 238         }
 239
 240         tag = (struct bcm_tag *) (buf + offset);
 241
 242         cfelen = strntoul(tag->cfe_length, NULL, 10, IMAGE_LEN);
 243         if (cfelen) {
 244           fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
 245           exit(1);
 246         }
 247
 248         if (quiet < 2) {
 249           fprintf(stderr, "Verifying we actually have an imagetag.\n");
 250         }
 251
 252         headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, header_crc), fd);
 253         if (headercrc != *(uint32_t *)(&tag->header_crc)) {
 254                 fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
 255                 exit(1);
 256         }
 257
 258         if (quiet < 2) {
 259           fprintf(stderr, "Checking current fixed status.\n");
 260         }
 261
 262         rootfslen = strntoul(&tag->root_length[0], NULL, 10, IMAGE_LEN);
 263         if (rootfslen == 0) {
 264           if (quiet < 2)
 265                 fprintf(stderr, "Header already fixed, exiting\n");
 266           close(fd);
 267           return 0;
 268         }
 269
 270         if (quiet < 2) {
 271           fprintf(stderr, "Setting root length to 0.\n");
 272         }
 273
 274         sprintf(&tag->root_length[0], "%u", 0);
 275         strncpy(&tag->total_length[0], &tag->kernel_length[0], IMAGE_LEN);
 276
 277         if (quiet < 2) {
 278           fprintf(stderr, "Recalculating CRCs.\n");
 279         }
 280
 281         imagestart = sizeof(tag);
 282         memcpy(&tag->image_crc, &tag->kernel_crc, sizeof(uint32_t));
 283         memcpy(&tag->fskernel_crc, &tag->kernel_crc, sizeof(uint32_t));
 284         rootfscrc = CRC_START;
 285         memcpy(&tag->rootfs_crc, &rootfscrc, sizeof(uint32_t));
 286         headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, header_crc));
 287         memcpy(&tag->header_crc, &headercrc, sizeof(uint32_t));
 288
 289         if (quiet < 2) {
 290           fprintf(stderr, "Erasing imagetag block\n");
 291         }
 292
 293         if (mtd_erase_block(fd, block_offset)) {
 294                 fprintf(stderr, "Can't erase block at 0x%x (%s)\n", block_offset, strerror(errno));
 295                 exit(1);
 296         }
 297
 298         if (quiet < 2) {
 299           fprintf(stderr, "New image crc32: 0x%x, rewriting block\n",
 300                           *(uint32_t *)(&tag->image_crc));
 301           fprintf(stderr, "New header crc32: 0x%x, rewriting block\n", headercrc);
 302         }
 303
 304         if (pwrite(fd, buf, erasesize, block_offset) != erasesize) {
 305                 fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
 306                 exit(1);
 307         }
 308
 309         if (quiet < 2)
 310                 fprintf(stderr, "Done.\n");
 311
 312         close (fd);
 313         sync();
 314         return 0;
 315
 316 }