libfstools/mtd.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <sys/mount.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <asm/byteorder.h>
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <mtd/mtd-user.h>
  23
  24 #include "libfstools.h"
  25
  26 #include "volume.h"
  27
  28 #define PATH_MAX                256
  29
  30 struct mtd_volume {
  31         struct volume v;
  32         int     fd;
  33         int     idx;
  34         char    *chr;
  35 };
  36
  37 static struct driver mtd_driver;
  38
  39 static int mtd_open(const char *mtd, int block)
  40 {
  41         FILE *fp;
  42         char dev[PATH_MAX];
  43         int i, ret, flags = O_RDWR | O_SYNC;
  44
  45         if ((fp = fopen("/proc/mtd", "r"))) {
  46                 while (fgets(dev, sizeof(dev), fp)) {
  47                         if (sscanf(dev, "mtd%d:", &i) && strstr(dev, mtd)) {
  48                                 snprintf(dev, sizeof(dev), "/dev/mtd%s/%d", (block ? "block" : ""), i);
  49                                 ret = open(dev, flags);
  50                                 if (ret < 0) {
  51                                         snprintf(dev, sizeof(dev), "/dev/mtd%s%d", (block ? "block" : ""), i);
  52                                         ret = open(dev, flags);
  53                                 }
  54                                 fclose(fp);
  55                                 return ret;
  56                         }
  57                 }
  58                 fclose(fp);
  59         }
  60
  61         return open(mtd, flags);
  62 }
  63
  64 static void mtd_volume_close(struct mtd_volume *p)
  65 {
  66         if (!p->fd)
  67                 return;
  68
  69         close(p->fd);
  70         p->fd = 0;
  71 }
  72
  73 static int mtd_volume_load(struct mtd_volume *p)
  74 {
  75         struct volume *v = &p->v;
  76         struct mtd_info_user mtdInfo;
  77         struct erase_info_user mtdLockInfo;
  78
  79         if (p->fd)
  80                 return 0;
  81
  82         if (!p->chr)
  83                 return -1;
  84
  85         p->fd = mtd_open(p->chr, 0);
  86         if (p->fd < 0) {
  87                 p->fd = 0;
  88                 ULOG_ERR("Could not open mtd device: %s\n", p->chr);
  89                 return -1;
  90         }
  91
  92         if (ioctl(p->fd, MEMGETINFO, &mtdInfo)) {
  93                 mtd_volume_close(p);
  94                 ULOG_ERR("Could not get MTD device info from %s\n", p->chr);
  95                 return -1;
  96         }
  97
  98         v->size = mtdInfo.size;
  99         v->block_size = mtdInfo.erasesize;
 100         switch (mtdInfo.type) {
 101         case MTD_NORFLASH:
 102                 v->type = NORFLASH;
 103                 break;
 104         case MTD_NANDFLASH:
 105                 v->type = NANDFLASH;
 106                 break;
 107         case MTD_UBIVOLUME:
 108                 v->type = UBIVOLUME;
 109                 break;
 110         default:
 111                 v->type = UNKNOWN_TYPE;
 112                 break;
 113         }
 114
 115         mtdLockInfo.start = 0;
 116         mtdLockInfo.length = v->size;
 117         ioctl(p->fd, MEMUNLOCK, &mtdLockInfo);
 118
 119         return 0;
 120 }
 121
 122 static char* mtd_find_index(char *name)
 123 {
 124         FILE *fp = fopen("/proc/mtd", "r");
 125         static char line[256];
 126         char *index = NULL;
 127
 128         if(!fp)
 129                 return index;
 130
 131         while (!index && fgets(line, sizeof(line), fp)) {
 132                 char *ret;
 133
 134                 if ((ret = strstr(line, name)) && (ret[strlen(name)] == '"')) {
 135                         char *eol = strstr(line, ":");
 136
 137                         if (!eol)
 138                                 continue;
 139
 140                         *eol = '\0';
 141                         index = &line[3];
 142                 }
 143         }
 144
 145         fclose(fp);
 146
 147         return index;
 148 }
 149
 150 static struct volume *mtd_volume_find(char *name)
 151 {
 152         char *idx = mtd_find_index(name);
 153         struct mtd_volume *p;
 154         struct volume *v;
 155         char buffer[32];
 156
 157         if (!idx)
 158                 return NULL;
 159
 160         p = calloc(1, sizeof(struct mtd_volume));
 161         if (!p)
 162                 return NULL;
 163
 164         v = &p->v;
 165         v->name = strdup(name);
 166         v->drv = &mtd_driver;
 167         p->idx = atoi(idx);
 168
 169         snprintf(buffer, sizeof(buffer), "/dev/mtdblock%s", idx);
 170         v->blk = strdup(buffer);
 171
 172         snprintf(buffer, sizeof(buffer), "/dev/mtd%s", idx);
 173         p->chr = strdup(buffer);
 174
 175         if (mtd_volume_load(p)) {
 176                 ULOG_ERR("reading %s failed\n", v->name);
 177                 free(p);
 178                 return NULL;
 179         }
 180
 181         return v;
 182 }
 183
 184 static int mtd_volume_identify(struct volume *v)
 185 {
 186         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 187         __u32 deadc0de;
 188         __u16 jffs2;
 189         size_t sz;
 190
 191         if (mtd_volume_load(p)) {
 192                 ULOG_ERR("reading %s failed\n", v->name);
 193                 return -1;
 194         }
 195
 196         sz = read(p->fd, &deadc0de, sizeof(deadc0de));
 197
 198         if (sz != sizeof(deadc0de)) {
 199                 ULOG_ERR("reading %s failed: %s\n", v->name, strerror(errno));
 200                 return -1;
 201         }
 202
 203         if (deadc0de == __be32_to_cpu(0x4f575254))
 204                 return FS_SNAPSHOT;
 205
 206         deadc0de = __be32_to_cpu(deadc0de);
 207         if (deadc0de == 0xdeadc0de) {
 208                 return FS_DEADCODE;
 209         }
 210
 211         jffs2 = __be16_to_cpu(deadc0de >> 16);
 212         if (jffs2 == 0x1985) {
 213                 return FS_JFFS2;
 214         }
 215
 216         if (v->type == UBIVOLUME && deadc0de == 0xffffffff) {
 217                 return FS_JFFS2;
 218         }
 219
 220         return FS_NONE;
 221 }
 222
 223 static int mtd_volume_erase(struct volume *v, int offset, int len)
 224 {
 225         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 226         struct erase_info_user eiu;
 227         int first_block, num_blocks;
 228
 229         if (mtd_volume_load(p))
 230                 return -1;
 231
 232         if (offset % v->block_size || len % v->block_size) {
 233                 ULOG_ERR("mtd erase needs to be block aligned\n");
 234                 return -1;
 235         }
 236
 237         first_block = offset / v->block_size;
 238         num_blocks = len / v->block_size;
 239         eiu.length = v->block_size;
 240
 241         for (eiu.start = first_block * v->block_size;
 242                         eiu.start < v->size && eiu.start < (first_block + num_blocks) * v->block_size;
 243                         eiu.start += v->block_size) {
 244                 ULOG_INFO("erasing %x %x\n", eiu.start, v->block_size);
 245                 ioctl(p->fd, MEMUNLOCK, &eiu);
 246                 if (ioctl(p->fd, MEMERASE, &eiu))
 247                         ULOG_ERR("Failed to erase block at 0x%x\n", eiu.start);
 248         }
 249
 250         mtd_volume_close(p);
 251
 252         return 0;
 253 }
 254
 255 static int mtd_volume_erase_all(struct volume *v)
 256 {
 257         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 258
 259         mtd_volume_erase(v, 0, v->size);
 260         mtd_volume_close(p);
 261
 262         return 0;
 263 }
 264
 265 static int mtd_volume_init(struct volume *v)
 266 {
 267         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 268         struct mtd_info_user mtdinfo;
 269         int ret;
 270
 271         if (mtd_volume_load(p))
 272                 return -1;
 273
 274         ret = ioctl(p->fd, MEMGETINFO, &mtdinfo);
 275         if (ret) {
 276                 ULOG_ERR("ioctl(%d, MEMGETINFO) failed: %s\n", p->fd, strerror(errno));
 277         } else {
 278                 struct erase_info_user mtdlock;
 279
 280                 mtdlock.start = 0;
 281                 mtdlock.length = mtdinfo.size;
 282                 ioctl(p->fd, MEMUNLOCK, &mtdlock);
 283         }
 284
 285         return ret;
 286 }
 287
 288 static int mtd_volume_read(struct volume *v, void *buf, int offset, int length)
 289 {
 290         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 291
 292         if (mtd_volume_load(p))
 293                 return -1;
 294
 295         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 296                 ULOG_ERR("lseek/read failed\n");
 297                 return -1;
 298         }
 299
 300         if (read(p->fd, buf, length) == -1) {
 301                 ULOG_ERR("read failed\n");
 302                 return -1;
 303         }
 304
 305         return 0;
 306 }
 307
 308 static int mtd_volume_write(struct volume *v, void *buf, int offset, int length)
 309 {
 310         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 311
 312         if (mtd_volume_load(p))
 313                 return -1;
 314
 315         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 316                 ULOG_ERR("lseek/write failed at offset %d\n", offset);
 317                 perror("lseek");
 318                 return -1;
 319         }
 320
 321         if (write(p->fd, buf, length) == -1) {
 322                 ULOG_ERR("write failed\n");
 323                 return -1;
 324         }
 325
 326         return 0;
 327 }
 328
 329 static struct driver mtd_driver = {
 330         .name = "mtd",
 331         .find = mtd_volume_find,
 332         .init = mtd_volume_init,
 333         .erase = mtd_volume_erase,
 334         .erase_all = mtd_volume_erase_all,
 335         .read = mtd_volume_read,
 336         .write = mtd_volume_write,
 337         .identify = mtd_volume_identify,
 338 };
 339 DRIVER(mtd_driver);