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 "mtd.h"
  36 #include "crc32.h"
  37 #include "bcm_tag.h"
  38
  39 ssize_t pread(int fd, void *buf, size_t count, off_t offset);
  40 ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
  41
  42 #define CRC_START 0xFFFFFFFF
  43
  44 static uint32_t strntoul(char *str, char **endptr, int base, size_t len) {
  45   char *newstr;
  46   uint32_t res = 0;
  47
  48   newstr = calloc(len + 1, sizeof(char));
  49   if (newstr) {
  50         strncpy(newstr, str, len);
  51         res = strtoul(newstr, endptr, base);
  52         free(newstr);
  53   }
  54   return res;
  55 }
  56
  57 uint32_t compute_crc32(uint32_t crc, off_t start, size_t compute_len, int fd)
  58 {
  59         uint8_t readbuf[1024];
  60         ssize_t res;
  61         off_t offset = start;
  62
  63         /* Read a buffer's worth of bytes  */
  64         while (fd && (compute_len >= sizeof(readbuf))) {
  65                 res = pread(fd, readbuf, sizeof(readbuf), offset);
  66                 crc = crc32(crc, readbuf, res);
  67                 compute_len = compute_len - res;
  68                 offset += res;
  69         }
  70
  71         /* Less than buffer-size bytes remains, read compute_len bytes */
  72         if (fd && (compute_len > 0)) {
  73           res = pread(fd, readbuf, compute_len, offset);
  74           crc = crc32(crc, readbuf, res);
  75         }
  76
  77         return crc;
  78 }
  79
  80 int
  81 trx_fixup(int fd, const char *name)
  82 {
  83         struct mtd_info_user mtdInfo;
  84         unsigned long len;
  85         void *ptr, *scan;
  86         int bfd;
  87         struct bcm_tag *tag;
  88         ssize_t res;
  89         uint32_t cfelen, imagelen, imagestart, rootfslen;
  90         uint32_t imagecrc, rootfscrc, headercrc;
  91         uint32_t offset = 0;
  92         cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;
  93
  94
  95         if (ioctl(fd, MEMGETINFO, &mtdInfo) < 0) {
  96                 fprintf(stderr, "Failed to get mtd info\n");
  97                 goto err;
  98         }
  99
 100         len = mtdInfo.size;
 101         if (mtdInfo.size <= 0) {
 102                 fprintf(stderr, "Invalid MTD device size\n");
 103                 goto err;
 104         }
 105
 106         bfd = mtd_open(name, true);
 107         ptr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, bfd, 0);
 108         if (!ptr || (ptr == (void *) -1)) {
 109                 perror("mmap");
 110                 goto err1;
 111         }
 112
 113         tag = (struct bcm_tag *) (ptr);
 114
 115         cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN);
 116         if (cfelen) {
 117           fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
 118           exit(1);
 119         }
 120
 121         headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd);
 122         if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) {
 123                 fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
 124                 exit(1);
 125         }
 126
 127         sprintf(&tag->flashRootLength[0], "%lu", 0);
 128         strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN);
 129
 130         imagestart = sizeof(tag);
 131         memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN);
 132         memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN);
 133         rootfscrc = CRC_START;
 134         memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t));
 135         headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC));
 136         memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t));
 137
 138         msync(ptr, sizeof(struct bcm_tag), MS_SYNC|MS_INVALIDATE);
 139         munmap(ptr, len);
 140         close(bfd);
 141         return 0;
 142
 143 err1:
 144         close(bfd);
 145 err:
 146         fprintf(stderr, "Error fixing up imagetag header\n");
 147         return -1;
 148 }
 149
 150
 151 int
 152 trx_check(int imagefd, const char *mtd, char *buf, int *len)
 153 {
 154     struct bcm_tag *tag = (const struct bcm_tag *) buf;
 155         int fd;
 156         uint32_t headerCRC;
 157         uint32_t imageLen;
 158
 159         if (strcmp(mtd, "linux") != 0)
 160                 return 1;
 161
 162         *len = read(imagefd, buf, sizeof(struct bcm_tag));
 163         if (*len < sizeof(struct bcm_tag)) {
 164                 fprintf(stdout, "Could not get image header, file too small (%d bytes)\n", *len);
 165                 return 0;
 166         }
 167         headerCRC = crc32buf(buf, offsetof(struct bcm_tag, headerCRC));
 168         if (*(uint32_t *)(&tag->headerCRC[0]) != headerCRC) {
 169
 170           if (quiet < 2) {
 171                 fprintf(stderr, "Bad header CRC got %08lx, calculated %08lx\n",
 172                                 *(uint32_t *)(&tag->headerCRC[0]), headerCRC);
 173                 fprintf(stderr, "This is not the correct file format; refusing to flash.\n"
 174                                 "Please specify the correct file or use -f to force.\n");
 175           }
 176           return 0;
 177         }
 178
 179         /* check if image fits to mtd device */
 180         fd = mtd_check_open(mtd);
 181         if(fd < 0) {
 182                 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 183                 exit(1);
 184         }
 185
 186         imageLen = strntoul(&tag->totalLength[0], NULL, 10, IMAGE_LEN);
 187
 188         if(mtdsize < imageLen) {
 189                 fprintf(stderr, "Image too big for partition: %s\n", mtd);
 190                 close(fd);
 191                 return 0;
 192         }
 193
 194         close(fd);
 195         return 1;
 196 }
 197
 198 int
 199 mtd_fixtrx(const char *mtd, size_t offset)
 200 {
 201         int fd;
 202         struct bcm_tag *tag;
 203         char *buf;
 204         ssize_t res;
 205         size_t block_offset;
 206         uint32_t cfelen, imagelen, imagestart, rootfslen;
 207         uint32_t imagecrc, rootfscrc, headercrc;
 208         cfelen = imagelen = imagestart = imagecrc = rootfscrc = headercrc = rootfslen = 0;
 209
 210         if (quiet < 2)
 211                 fprintf(stderr, "Trying to fix trx header in %s at 0x%x...\n", mtd, offset);
 212
 213         block_offset = offset & ~(erasesize - 1);
 214         offset -= block_offset;
 215
 216         fd = mtd_check_open(mtd);
 217         if(fd < 0) {
 218                 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 219                 exit(1);
 220         }
 221
 222         if (block_offset + erasesize > mtdsize) {
 223                 fprintf(stderr, "Offset too large, device size 0x%x\n", mtdsize);
 224                 exit(1);
 225         }
 226
 227         buf = malloc(erasesize);
 228         if (!buf) {
 229                 perror("malloc");
 230                 exit(1);
 231         }
 232
 233         res = pread(fd, buf, erasesize, block_offset);
 234         if (res != erasesize) {
 235                 perror("pread");
 236                 exit(1);
 237         }
 238
 239         tag = (struct bcm_tag *) (buf + offset);
 240
 241         cfelen = strntoul(&tag->cfeLength[0], NULL, 10, IMAGE_LEN);
 242         if (cfelen) {
 243           fprintf(stderr, "Non-zero CFE length.  This is currently unsupported.\n");
 244           exit(1);
 245         }
 246
 247         if (quiet < 2) {
 248           fprintf(stderr, "Verifying we actually have an imagetag.\n");
 249         }
 250
 251         headercrc = compute_crc32(CRC_START, offset, offsetof(struct bcm_tag, headerCRC), fd);
 252         if (headercrc != *(uint32_t *)(&tag->headerCRC[0])) {
 253                 fprintf(stderr, "Tag verify failed.  This may not be a valid image.\n");
 254                 exit(1);
 255         }
 256
 257         if (quiet < 2) {
 258           fprintf(stderr, "Checking current fixed status.\n");
 259         }
 260
 261         rootfslen = strntoul(&tag->flashRootLength[0], NULL, 10, IMAGE_LEN);
 262         if (rootfslen == 0) {
 263           if (quiet < 2)
 264                 fprintf(stderr, "Header already fixed, exiting\n");
 265           close(fd);
 266           return 0;
 267         }
 268
 269         if (quiet < 2) {
 270           fprintf(stderr, "Setting root length to 0.\n");
 271         }
 272
 273         sprintf(&tag->flashRootLength[0], "%lu", 0);
 274         strncpy(&tag->totalLength[0], &tag->kernelLength[0], IMAGE_LEN);
 275
 276         if (quiet < 2) {
 277           fprintf(stderr, "Recalculating CRCs.\n");
 278         }
 279
 280         imagestart = sizeof(tag);
 281         memcpy(&tag->imageCRC[0], &tag->kernelCRC[0], CRC_LEN);
 282         memcpy(&tag->fskernelCRC[0], &tag->kernelCRC[0], CRC_LEN);
 283         rootfscrc = CRC_START;
 284         memcpy(&tag->rootfsCRC[0], &rootfscrc, sizeof(uint32_t));
 285         headercrc = crc32(CRC_START, tag, offsetof(struct bcm_tag, headerCRC));
 286         memcpy(&tag->headerCRC[0], &headercrc, sizeof(uint32_t));
 287
 288         if (quiet < 2) {
 289           fprintf(stderr, "Erasing imagetag block\n");
 290         }
 291
 292         if (mtd_erase_block(fd, block_offset)) {
 293                 fprintf(stderr, "Can't erase block at 0x%x (%s)\n", block_offset, strerror(errno));
 294                 exit(1);
 295         }
 296
 297         if (quiet < 2) {
 298           fprintf(stderr, "New image crc32: 0x%x, rewriting block\n",
 299                           *(uint32_t *)(&tag->imageCRC[0]));
 300           fprintf(stderr, "New header crc32: 0x%x, rewriting block\n", headercrc);
 301         }
 302
 303         if (pwrite(fd, buf, erasesize, block_offset) != erasesize) {
 304                 fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
 305                 exit(1);
 306         }
 307
 308         if (quiet < 2)
 309                 fprintf(stderr, "Done.\n");
 310
 311         close (fd);
 312         sync();
 313         return 0;
 314
 315 }