dac5da2b8566e39de4c556cc289d68b7f5e7dcbd
[openwrt/svn-archive/archive.git] / package / system / mtd / src / seama.c
1 /*
2 * seama.c
3 *
4 * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
5 *
6 * Based on the trx fixup code:
7 * Copyright (C) 2005 Mike Baker
8 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 */
24
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <stddef.h>
28 #include <unistd.h>
29 #include <fcntl.h>
30 #include <sys/mman.h>
31 #include <sys/stat.h>
32 #include <string.h>
33 #include <errno.h>
34 #include <arpa/inet.h>
35
36 #include <sys/ioctl.h>
37 #include <mtd/mtd-user.h>
38 #include "mtd.h"
39 #include "seama.h"
40 #include "md5.h"
41
42 #if __BYTE_ORDER == __BIG_ENDIAN
43 #define STORE32_LE(X) ((((X) & 0x000000FF) << 24) | (((X) & 0x0000FF00) << 8) | (((X) & 0x00FF0000) >> 8) | (((X) & 0xFF000000) >> 24))
44 #elif __BYTE_ORDER == __LITTLE_ENDIAN
45 #define STORE32_LE(X) (X)
46 #else
47 #error unknown endianness!
48 #endif
49
50 ssize_t pread(int fd, void *buf, size_t count, off_t offset);
51 ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
52
53 int
54 seama_fix_md5(struct seama_entity_header *shdr, int fd, size_t len, size_t block_offset)
55 {
56 char *buf;
57 char *data;
58 ssize_t res;
59 size_t msize;
60 size_t isize;
61 MD5_CTX ctx;
62 unsigned char digest[16];
63 int i;
64 int err = 0;
65
66 if (len < sizeof(struct seama_entity_header))
67 return -1;
68
69 buf = malloc(len);
70 if (!buf) {
71 err = -ENOMEM;
72 goto err_out;
73 }
74
75 res = pread(fd, buf, len, block_offset);
76 if (res != len) {
77 perror("pread");
78 err = -EIO;
79 goto err_free;
80 }
81
82 isize = ntohl(shdr->size);
83 msize = ntohs(shdr->metasize);
84 if (isize == 0) {
85 /* the image contains no checksum */
86 return -1;
87 }
88
89 len -= sizeof(struct seama_entity_header) + msize;
90 if (isize > len)
91 isize = len;
92
93 data = buf + sizeof(struct seama_entity_header) + msize;
94
95 MD5_Init(&ctx);
96 MD5_Update(&ctx, data, isize);
97 MD5_Final(digest, &ctx);
98
99 if (!memcmp(digest, shdr->md5, sizeof(digest))) {
100 if (quiet < 2)
101 fprintf(stderr, "the header is fixed already\n");
102 return -1;
103 }
104
105 if (quiet < 2) {
106 fprintf(stderr, "new size:%u, new MD5: ", isize);
107 for (i = 0; i < sizeof(digest); i++)
108 fprintf(stderr, "%02x", digest[i]);
109
110 fprintf(stderr, "\n");
111 }
112
113 /* update the size in the image */
114 shdr->size = htonl(isize);
115
116 /* update the checksum in the image */
117 memcpy(shdr->md5, digest, sizeof(digest));
118
119 err_free:
120 free(buf);
121 err_out:
122 return err;
123 }
124
125 int
126 mtd_fixseama(const char *mtd, size_t offset)
127 {
128 int fd;
129 char *first_block;
130 ssize_t res;
131 size_t block_offset;
132 struct seama_entity_header *shdr;
133
134 if (quiet < 2)
135 fprintf(stderr, "Trying to fix SEAMA header in %s at 0x%x...\n",
136 mtd, offset);
137
138 block_offset = offset & ~(erasesize - 1);
139 offset -= block_offset;
140
141 fd = mtd_check_open(mtd);
142 if(fd < 0) {
143 fprintf(stderr, "Could not open mtd device: %s\n", mtd);
144 exit(1);
145 }
146
147 if (block_offset + erasesize > mtdsize) {
148 fprintf(stderr, "Offset too large, device size 0x%x\n",
149 mtdsize);
150 exit(1);
151 }
152
153 first_block = malloc(erasesize);
154 if (!first_block) {
155 perror("malloc");
156 exit(1);
157 }
158
159 res = pread(fd, first_block, erasesize, block_offset);
160 if (res != erasesize) {
161 perror("pread");
162 exit(1);
163 }
164
165 shdr = (struct seama_entity_header *)first_block;
166 if (shdr->magic != htonl(SEAMA_MAGIC)) {
167 fprintf(stderr, "No SEAMA header found\n");
168 return -1;
169 }
170
171 if (seama_fix_md5(shdr, fd, mtdsize, block_offset))
172 goto out;
173
174 if (mtd_erase_block(fd, block_offset)) {
175 fprintf(stderr, "Can't erease block at 0x%x (%s)\n",
176 block_offset, strerror(errno));
177 exit(1);
178 }
179
180 if (quiet < 2)
181 fprintf(stderr, "Rewriting block at 0x%x\n", block_offset);
182
183 if (pwrite(fd, first_block, erasesize, block_offset) != erasesize) {
184 fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
185 exit(1);
186 }
187
188 if (quiet < 2)
189 fprintf(stderr, "Done.\n");
190
191 out:
192 close (fd);
193 sync();
194
195 return 0;
196 }
197