Root/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
39ssize_t pread(int fd, void *buf, size_t count, off_t offset);
40ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
41
42#define CRC_START 0xFFFFFFFF
43
44static 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
57uint32_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
80int
81trx_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
143err1:
144    close(bfd);
145err:
146    fprintf(stderr, "Error fixing up imagetag header\n");
147    return -1;
148}
149
150
151int
152trx_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
198int
199mtd_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}
316

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