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