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                 lseek(p->fd, 0, SEEK_SET);
  81                 return 0;
  82         }
  83
  84         if (!p->chr)
  85                 return -1;
  86
  87         p->fd = mtd_open(p->chr, 0);
  88         if (p->fd < 0) {
  89                 p->fd = 0;
  90                 ULOG_ERR("Could not open mtd device: %s\n", p->chr);
  91                 return -1;
  92         }
  93
  94         if (ioctl(p->fd, MEMGETINFO, &mtdInfo)) {
  95                 mtd_volume_close(p);
  96                 ULOG_ERR("Could not get MTD device info from %s\n", p->chr);
  97                 return -1;
  98         }
  99
 100         v->size = mtdInfo.size;
 101         v->block_size = mtdInfo.erasesize;
 102         switch (mtdInfo.type) {
 103         case MTD_NORFLASH:
 104                 v->type = NORFLASH;
 105                 break;
 106         case MTD_NANDFLASH:
 107                 v->type = NANDFLASH;
 108                 break;
 109         case MTD_UBIVOLUME:
 110                 v->type = UBIVOLUME;
 111                 break;
 112         default:
 113                 v->type = UNKNOWN_TYPE;
 114                 break;
 115         }
 116
 117         mtdLockInfo.start = 0;
 118         mtdLockInfo.length = v->size;
 119         ioctl(p->fd, MEMUNLOCK, &mtdLockInfo);
 120
 121         return 0;
 122 }
 123
 124 static char* mtd_find_index(char *name)
 125 {
 126         FILE *fp = fopen("/proc/mtd", "r");
 127         static char line[256];
 128         char *index = NULL;
 129
 130         if(!fp)
 131                 return index;
 132
 133         while (!index && fgets(line, sizeof(line), fp)) {
 134                 char *ret;
 135
 136                 if ((ret = strstr(line, name)) && (ret[strlen(name)] == '"')) {
 137                         char *eol = strstr(line, ":");
 138
 139                         if (!eol)
 140                                 continue;
 141
 142                         *eol = '\0';
 143                         index = &line[3];
 144                 }
 145         }
 146
 147         fclose(fp);
 148
 149         return index;
 150 }
 151
 152 static struct volume *mtd_volume_find(char *name)
 153 {
 154         char *idx = mtd_find_index(name);
 155         struct mtd_volume *p;
 156         struct volume *v;
 157         char buffer[32];
 158
 159         if (!idx)
 160                 return NULL;
 161
 162         p = calloc(1, sizeof(struct mtd_volume));
 163         if (!p)
 164                 return NULL;
 165
 166         v = &p->v;
 167         v->name = strdup(name);
 168         v->drv = &mtd_driver;
 169         p->idx = atoi(idx);
 170
 171         snprintf(buffer, sizeof(buffer), "/dev/mtdblock%s", idx);
 172         v->blk = strdup(buffer);
 173
 174         snprintf(buffer, sizeof(buffer), "/dev/mtd%s", idx);
 175         p->chr = strdup(buffer);
 176
 177         if (mtd_volume_load(p)) {
 178                 ULOG_ERR("reading %s failed\n", v->name);
 179                 free(p);
 180                 return NULL;
 181         }
 182
 183         return v;
 184 }
 185
 186 static int mtd_volume_identify(struct volume *v)
 187 {
 188         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 189         __u32 deadc0de;
 190         __u16 jffs2;
 191         size_t sz;
 192
 193         if (mtd_volume_load(p)) {
 194                 ULOG_ERR("reading %s failed\n", v->name);
 195                 return -1;
 196         }
 197
 198         sz = read(p->fd, &deadc0de, sizeof(deadc0de));
 199
 200         if (sz != sizeof(deadc0de)) {
 201                 ULOG_ERR("reading %s failed: %m\n", v->name);
 202                 return -1;
 203         }
 204
 205         if (deadc0de == __be32_to_cpu(0x4f575254))
 206                 return FS_SNAPSHOT;
 207
 208         deadc0de = __be32_to_cpu(deadc0de);
 209         if (deadc0de == 0xdeadc0de) {
 210                 return FS_DEADCODE;
 211         }
 212
 213         jffs2 = __be16_to_cpu(deadc0de >> 16);
 214         if (jffs2 == 0x1985) {
 215                 return FS_JFFS2;
 216         }
 217
 218         if (v->type == UBIVOLUME && deadc0de == 0xffffffff) {
 219                 return FS_JFFS2;
 220         }
 221
 222         return FS_NONE;
 223 }
 224
 225 static int mtd_volume_erase(struct volume *v, int offset, int len)
 226 {
 227         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 228         struct erase_info_user eiu;
 229         int first_block, num_blocks;
 230
 231         if (mtd_volume_load(p))
 232                 return -1;
 233
 234         if (offset % v->block_size || len % v->block_size) {
 235                 ULOG_ERR("mtd erase needs to be block aligned\n");
 236                 return -1;
 237         }
 238
 239         first_block = offset / v->block_size;
 240         num_blocks = len / v->block_size;
 241         eiu.length = v->block_size;
 242
 243         for (eiu.start = first_block * v->block_size;
 244                         eiu.start < v->size && eiu.start < (first_block + num_blocks) * v->block_size;
 245                         eiu.start += v->block_size) {
 246                 ULOG_INFO("erasing %x %x\n", eiu.start, v->block_size);
 247                 ioctl(p->fd, MEMUNLOCK, &eiu);
 248                 if (ioctl(p->fd, MEMERASE, &eiu))
 249                         ULOG_ERR("Failed to erase block at 0x%x\n", eiu.start);
 250         }
 251
 252         mtd_volume_close(p);
 253
 254         return 0;
 255 }
 256
 257 static int mtd_volume_erase_all(struct volume *v)
 258 {
 259         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 260
 261         mtd_volume_erase(v, 0, v->size);
 262         mtd_volume_close(p);
 263
 264         return 0;
 265 }
 266
 267 static int mtd_volume_init(struct volume *v)
 268 {
 269         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 270         struct mtd_info_user mtdinfo;
 271         int ret;
 272
 273         if (mtd_volume_load(p))
 274                 return -1;
 275
 276         ret = ioctl(p->fd, MEMGETINFO, &mtdinfo);
 277         if (ret) {
 278                 ULOG_ERR("ioctl(%d, MEMGETINFO) failed: %m\n", p->fd);
 279         } else {
 280                 struct erase_info_user mtdlock;
 281
 282                 mtdlock.start = 0;
 283                 mtdlock.length = mtdinfo.size;
 284                 ioctl(p->fd, MEMUNLOCK, &mtdlock);
 285         }
 286
 287         return ret;
 288 }
 289
 290 static int mtd_volume_read(struct volume *v, void *buf, int offset, int length)
 291 {
 292         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 293
 294         if (mtd_volume_load(p))
 295                 return -1;
 296
 297         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 298                 ULOG_ERR("lseek/read failed\n");
 299                 return -1;
 300         }
 301
 302         if (read(p->fd, buf, length) == -1) {
 303                 ULOG_ERR("read failed\n");
 304                 return -1;
 305         }
 306
 307         return 0;
 308 }
 309
 310 static int mtd_volume_write(struct volume *v, void *buf, int offset, int length)
 311 {
 312         struct mtd_volume *p = container_of(v, struct mtd_volume, v);;
 313
 314         if (mtd_volume_load(p))
 315                 return -1;
 316
 317         if (lseek(p->fd, offset, SEEK_SET) == (off_t) -1) {
 318                 ULOG_ERR("lseek/write failed at offset %d\n", offset);
 319                 perror("lseek");
 320                 return -1;
 321         }
 322
 323         if (write(p->fd, buf, length) == -1) {
 324                 ULOG_ERR("write failed\n");
 325                 return -1;
 326         }
 327
 328         return 0;
 329 }
 330
 331 static struct driver mtd_driver = {
 332         .name = "mtd",
 333         .find = mtd_volume_find,
 334         .init = mtd_volume_init,
 335         .erase = mtd_volume_erase,
 336         .erase_all = mtd_volume_erase_all,
 337         .read = mtd_volume_read,
 338         .write = mtd_volume_write,
 339         .identify = mtd_volume_identify,
 340 };
 341 DRIVER(mtd_driver);