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 = -1;
  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 >= 0)
  80                 return (lseek(p->fd, 0, SEEK_SET) == -1);
  81
  82         if (!p->chr)
  83                 return -1;
  84
  85         p->fd = mtd_open(p->chr, 0);
  86         if (p->fd < 0) {
  87                 ULOG_ERR("Could not open mtd device: %s\n", p->chr);
  88                 return -1;
  89         }
  90
  91         if (ioctl(p->fd, MEMGETINFO, &mtdInfo)) {
  92                 mtd_volume_close(p);
  93                 ULOG_ERR("Could not get MTD device info from %s\n", p->chr);
  94                 return -1;
  95         }
  96
  97         v->size = mtdInfo.size;
  98         v->block_size = mtdInfo.erasesize;
  99         switch (mtdInfo.type) {
 100         case MTD_NORFLASH:
 101                 v->type = NORFLASH;
 102                 break;
 103         case MTD_NANDFLASH:
 104                 v->type = NANDFLASH;
 105                 break;
 106         case MTD_UBIVOLUME:
 107                 v->type = UBIVOLUME;
 108                 break;
 109         default:
 110                 v->type = UNKNOWN_TYPE;
 111                 break;
 112         }
 113
 114         mtdLockInfo.start = 0;
 115         mtdLockInfo.length = v->size;
 116         ioctl(p->fd, MEMUNLOCK, &mtdLockInfo);
 117
 118         return 0;
 119 }
 120
 121 static char* mtd_find_index(char *name)
 122 {
 123         FILE *fp = fopen("/proc/mtd", "r");
 124         static char line[256];
 125         char *index = NULL;
 126
 127         if(!fp)
 128                 return index;
 129
 130         while (!index && fgets(line, sizeof(line), fp)) {
 131                 char *ret;
 132
 133                 if ((ret = strstr(line, name)) && (ret[strlen(name)] == '"')) {
 134                         char *eol = strstr(line, ":");
 135
 136                         if (!eol)
 137                                 continue;
 138
 139                         *eol = '\0';
 140                         index = &line[3];
 141                 }
 142         }
 143
 144         fclose(fp);
 145
 146         return index;
 147 }
 148
 149 static struct volume *mtd_volume_find(char *name)
 150 {
 151         char *idx = mtd_find_index(name);
 152         struct mtd_volume *p;
 153         struct volume *v;
 154         char buffer[32];
 155
 156         if (!idx)
 157                 return NULL;
 158
 159         p = calloc(1, sizeof(struct mtd_volume));
 160         if (!p)
 161                 return NULL;
 162
 163         v = &p->v;
 164         v->name = strdup(name);
 165         v->drv = &mtd_driver;
 166         p->idx = atoi(idx);
 167         p->fd = -1;
 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         size_t sz;
 189
 190         if (mtd_volume_load(p)) {
 191                 ULOG_ERR("reading %s failed\n", v->name);
 192                 return -1;
 193         }
 194
 195         sz = read(p->fd, &deadc0de, sizeof(deadc0de));
 196
 197         if (sz != sizeof(deadc0de)) {
 198                 ULOG_ERR("reading %s failed: %m\n", v->name);
 199                 return -1;
 200         }
 201
 202         if (deadc0de == ~0) {
 203                 struct mtd_oob_buf oob = {
 204                         .start = 0,
 205                         .length = sizeof(deadc0de),
 206                         .ptr = (void *)&deadc0de,
 207                 };
 208
 209                 ioctl(p->fd, MEMREADOOB, &oob);
 210         }
 211
 212         if (deadc0de == __be32_to_cpu(0x4f575254))
 213                 return FS_SNAPSHOT;
 214
 215         deadc0de = __be32_to_cpu(deadc0de);
 216         if (deadc0de == 0xdeadc0de) {
 217                 return FS_DEADCODE;
 218         }
 219
 220         if (__be16_to_cpu(deadc0de) == 0x1985 ||
 221             __be16_to_cpu(deadc0de >> 16) == 0x1985)
 222                 return FS_JFFS2;
 223
 224         if (v->type == UBIVOLUME && deadc0de == 0xffffffff) {
 225                 return FS_JFFS2;
 226         }
 227
 228         return FS_NONE;
 229 }
 230
 231 static int mtd_volume_erase(struct volume *v, int offset, int len)
 232 {
 233         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 234         struct erase_info_user eiu;
 235         int first_block, num_blocks;
 236
 237         if (mtd_volume_load(p))
 238                 return -1;
 239
 240         if (offset % v->block_size || len % v->block_size) {
 241                 ULOG_ERR("mtd erase needs to be block aligned\n");
 242                 return -1;
 243         }
 244
 245         first_block = offset / v->block_size;
 246         num_blocks = len / v->block_size;
 247         eiu.length = v->block_size;
 248
 249         for (eiu.start = first_block * v->block_size;
 250                         eiu.start < v->size && eiu.start < (first_block + num_blocks) * v->block_size;
 251                         eiu.start += v->block_size) {
 252                 ULOG_INFO("erasing %x %x\n", eiu.start, v->block_size);
 253                 ioctl(p->fd, MEMUNLOCK, &eiu);
 254                 if (ioctl(p->fd, MEMERASE, &eiu))
 255                         ULOG_ERR("Failed to erase block at 0x%x\n", eiu.start);
 256         }
 257
 258         mtd_volume_close(p);
 259
 260         return 0;
 261 }
 262
 263 static int mtd_volume_erase_all(struct volume *v)
 264 {
 265         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 266
 267         mtd_volume_erase(v, 0, v->size);
 268         mtd_volume_close(p);
 269
 270         return 0;
 271 }
 272
 273 static int mtd_volume_init(struct volume *v)
 274 {
 275         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 276         struct mtd_info_user mtdinfo;
 277         int ret;
 278
 279         if (mtd_volume_load(p))
 280                 return -1;
 281
 282         ret = ioctl(p->fd, MEMGETINFO, &mtdinfo);
 283         if (ret) {
 284                 ULOG_ERR("ioctl(%d, MEMGETINFO) failed: %m\n", p->fd);
 285         } else {
 286                 struct erase_info_user mtdlock;
 287
 288                 mtdlock.start = 0;
 289                 mtdlock.length = mtdinfo.size;
 290                 ioctl(p->fd, MEMUNLOCK, &mtdlock);
 291         }
 292
 293         return ret;
 294 }
 295
 296 static int mtd_volume_read(struct volume *v, void *buf, int offset, int length)
 297 {
 298         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 299
 300         if (mtd_volume_load(p))
 301                 return -1;
 302
 303         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 304                 ULOG_ERR("lseek/read failed\n");
 305                 return -1;
 306         }
 307
 308         if (read(p->fd, buf, length) == -1) {
 309                 ULOG_ERR("read failed\n");
 310                 return -1;
 311         }
 312
 313         return 0;
 314 }
 315
 316 static int mtd_volume_write(struct volume *v, void *buf, int offset, int length)
 317 {
 318         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 319
 320         if (mtd_volume_load(p))
 321                 return -1;
 322
 323         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 324                 ULOG_ERR("lseek/write failed at offset %d\n", offset);
 325                 perror("lseek");
 326                 return -1;
 327         }
 328
 329         if (write(p->fd, buf, length) == -1) {
 330                 ULOG_ERR("write failed\n");
 331                 return -1;
 332         }
 333
 334         return 0;
 335 }
 336
 337 static struct driver mtd_driver = {
 338         .name = "mtd",
 339         .find = mtd_volume_find,
 340         .init = mtd_volume_init,
 341         .erase = mtd_volume_erase,
 342         .erase_all = mtd_volume_erase_all,
 343         .read = mtd_volume_read,
 344         .write = mtd_volume_write,
 345         .identify = mtd_volume_identify,
 346 };
 347 DRIVER(mtd_driver);