package/utils/fritz-tools/src/fritz_tffs_nand_read.c

   1 /*
   2  * A tool for reading the TFFS partitions (a name-value storage usually
   3  * found in AVM Fritz!Box based devices) on nand flash.
   4  *
   5  * Copyright (c) 2018 Valentin Spreckels <Valentin.Spreckels@Informatik.Uni-Oldenburg.DE>
   6  *
   7  * Based on the fritz_tffs_read tool:
   8  *     Copyright (c) 2015-2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
   9  * and on the TFFS 2.0 kernel driver from AVM:
  10  *     Copyright (c) 2004-2007 AVM GmbH <fritzbox_info@avm.de>
  11  * and the TFFS 3.0 kernel driver from AVM:
  12  *     Copyright (C) 2004-2014 AVM GmbH <fritzbox_info@avm.de>
  13  * and the OpenWrt TFFS kernel driver:
  14  *     Copyright (c) 2013 John Crispin <john@phrozen.org>
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 2 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License along
  27  * with this program; if not, write to the Free Software Foundation, Inc.,
  28  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  29  */
  30
  31 #include <stdbool.h>
  32 #include <stddef.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <stdint.h>
  36 #include <string.h>
  37 #include <libgen.h>
  38 #include <getopt.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <endian.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/types.h>
  44 #include <sys/stat.h>
  45 #include <arpa/inet.h>
  46 #include <mtd/mtd-user.h>
  47 #include <assert.h>
  48
  49 #define DEFAULT_TFFS_SIZE       (256 * 1024)
  50
  51 #define TFFS_ID_END             0xffffffff
  52 #define TFFS_ID_TABLE_NAME      0x000001ff
  53
  54 #define TFFS_BLOCK_HEADER_MAGIC 0x41564d5f54464653ULL
  55 #define TFFS_VERSION            0x0003
  56 #define TFFS_ENTRY_HEADER_SIZE  0x18
  57 #define TFFS_MAXIMUM_SEGMENT_SIZE       (0x800 - TFFS_ENTRY_HEADER_SIZE)
  58
  59 #define TFFS_SECTOR_SIZE 0x0800
  60 #define TFFS_SECTOR_OOB_SIZE 0x0040
  61 #define TFFS_SECTORS_PER_PAGE 2
  62
  63 #define TFFS_SEGMENT_CLEARED 0xffffffff
  64
  65 static char *progname;
  66 static char *mtddev;
  67 static char *name_filter = NULL;
  68 static bool show_all = false;
  69 static bool print_all_key_names = false;
  70 static bool read_oob_sector_health = false;
  71 static bool swap_bytes = false;
  72 static uint8_t readbuf[TFFS_SECTOR_SIZE];
  73 static uint8_t oobbuf[TFFS_SECTOR_OOB_SIZE];
  74 static uint32_t blocksize;
  75 static int mtdfd;
  76 struct tffs_sectors *sectors;
  77
  78 struct tffs_sectors {
  79         uint32_t num_sectors;
  80         uint8_t sectors[0];
  81 };
  82
  83 static inline void sector_mark_bad(int num)
  84 {
  85         sectors->sectors[num / 8] &= ~(0x80 >> (num % 8));
  86 };
  87
  88 static inline uint8_t sector_get_good(int num)
  89 {
  90         return sectors->sectors[num / 8] & 0x80 >> (num % 8);
  91 };
  92
  93 struct tffs_entry_segment {
  94         uint32_t len;
  95         void *val;
  96 };
  97
  98 struct tffs_entry {
  99         uint32_t len;
 100         void *val;
 101 };
 102
 103 struct tffs_name_table_entry {
 104         uint32_t id;
 105         char *val;
 106 };
 107
 108 struct tffs_key_name_table {
 109         uint32_t size;
 110         struct tffs_name_table_entry *entries;
 111 };
 112
 113 static inline uint8_t read_uint8(void *buf, ptrdiff_t off)
 114 {
 115         return *(uint8_t *)(buf + off);
 116 }
 117
 118 static inline uint32_t read_uint32(void *buf, ptrdiff_t off)
 119 {
 120         uint32_t tmp = *(uint32_t *)(buf + off);
 121         if (swap_bytes) {
 122                 tmp = be32toh(tmp);
 123         }
 124         return tmp;
 125 }
 126
 127 static inline uint64_t read_uint64(void *buf, ptrdiff_t off)
 128 {
 129         uint64_t tmp = *(uint64_t *)(buf + off);
 130         if (swap_bytes) {
 131                 tmp = be64toh(tmp);
 132         }
 133         return tmp;
 134 }
 135
 136 static int read_sector(off_t pos)
 137 {
 138         if (pread(mtdfd, readbuf, TFFS_SECTOR_SIZE, pos) != TFFS_SECTOR_SIZE) {
 139                 return -1;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static int read_sectoroob(off_t pos)
 146 {
 147         struct mtd_oob_buf oob = {
 148                 .start = pos,
 149                 .length = TFFS_SECTOR_OOB_SIZE,
 150                 .ptr = oobbuf
 151         };
 152
 153         if (ioctl(mtdfd, MEMREADOOB, &oob) < 0) {
 154                 return -1;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static inline uint32_t get_walk_size(uint32_t entry_len)
 161 {
 162         return (entry_len + 3) & ~0x03;
 163 }
 164
 165 static void print_entry_value(const struct tffs_entry *entry)
 166 {
 167         /* These are NOT NULL terminated. */
 168         fwrite(entry->val, 1, entry->len, stdout);
 169 }
 170
 171 static int find_entry(uint32_t id, struct tffs_entry *entry)
 172 {
 173         uint32_t rev = 0;
 174         uint32_t num_segments = 0;
 175         struct tffs_entry_segment *segments = NULL;
 176
 177         off_t pos = 0;
 178         uint8_t block_end = 0;
 179         for (uint32_t sector = 0; sector < sectors->num_sectors; sector++, pos += TFFS_SECTOR_SIZE) {
 180                 if (block_end) {
 181                         if (pos % blocksize == 0) {
 182                                 block_end = 0;
 183                         }
 184                 } else if (sector_get_good(sector)) {
 185                         if (read_sectoroob(pos) || read_sector(pos)) {
 186                                 fprintf(stderr, "ERROR: sector isn't readable, but has been previously!\n");
 187                                 exit(EXIT_FAILURE);
 188                         }
 189                         uint32_t oob_id = read_uint32(oobbuf, 0x02);
 190                         uint32_t oob_len = read_uint32(oobbuf, 0x06);
 191                         uint32_t oob_rev = read_uint32(oobbuf, 0x0a);
 192                         uint32_t read_id = read_uint32(readbuf, 0x00);
 193                         uint32_t read_len = read_uint32(readbuf, 0x04);
 194                         uint32_t read_rev = read_uint32(readbuf, 0x0c);
 195                         if (read_oob_sector_health && (oob_id != read_id || oob_len != read_len || oob_rev != read_rev)) {
 196                                 fprintf(stderr, "Warning: sector has inconsistent metadata\n");
 197                                 continue;
 198                         }
 199                         if (read_id == TFFS_ID_END) {
 200                                 /* no more entries in this block */
 201                                 block_end = 1;
 202                                 continue;
 203                         }
 204                         if (read_len > TFFS_MAXIMUM_SEGMENT_SIZE) {
 205                                 fprintf(stderr, "Warning: segment is longer than possible\n");
 206                                 continue;
 207                         }
 208                         if (read_id == id) {
 209                                 if (read_rev < rev) {
 210                                         /* obsolete revision => ignore this */
 211                                         continue;
 212                                 }
 213                                 if (read_rev > rev) {
 214                                         /* newer revision => clear old data */
 215                                         for (uint32_t i = 0; i < num_segments; i++) {
 216                                                 free(segments[i].val);
 217                                         }
 218                                         free (segments);
 219                                         rev = read_rev;
 220                                         num_segments = 0;
 221                                         segments = NULL;
 222                                 }
 223
 224                                 uint32_t seg = read_uint32(readbuf, 0x10);
 225
 226                                 if (seg == TFFS_SEGMENT_CLEARED) {
 227                                         continue;
 228                                 }
 229
 230                                 uint32_t next_seg = read_uint32(readbuf, 0x14);
 231
 232                                 uint32_t new_num_segs = next_seg == 0 ? seg + 1 : next_seg + 1;
 233                                 if (new_num_segs > num_segments) {
 234                                         segments = realloc(segments, new_num_segs * sizeof(struct tffs_entry_segment));
 235                                         memset(segments + (num_segments * sizeof(struct tffs_entry_segment)), 0x0,
 236                                                         (new_num_segs - num_segments) * sizeof(struct tffs_entry_segment));
 237                                         num_segments = new_num_segs;
 238                                 }
 239                                 segments[seg].len = read_len;
 240                                 segments[seg].val = malloc(read_len);
 241                                 memcpy(segments[seg].val, readbuf + TFFS_ENTRY_HEADER_SIZE, read_len);
 242                         }
 243                 }
 244         }
 245
 246         if (num_segments == 0) {
 247                 return 0;
 248         }
 249
 250         assert (segments != NULL);
 251
 252         uint32_t len = 0;
 253         for (uint32_t i = 0; i < num_segments; i++) {
 254                 if (segments[i].val == NULL) {
 255                         /* missing segment */
 256                         return 0;
 257                 }
 258
 259                 len += segments[i].len;
 260         }
 261
 262         void *p = malloc(len);
 263         entry->val = p;
 264         entry->len = len;
 265         for (uint32_t i = 0; i < num_segments; i++) {
 266                 memcpy(p, segments[i].val, segments[i].len);
 267                 p += segments[i].len;
 268         }
 269
 270         return 1;
 271 }
 272
 273 static void parse_key_names(struct tffs_entry *names_entry,
 274                              struct tffs_key_name_table *key_names)
 275 {
 276         uint32_t pos = 0, i = 0;
 277         struct tffs_name_table_entry *name_item;
 278
 279         key_names->entries = NULL;
 280
 281         do {
 282                 key_names->entries = realloc(key_names->entries,
 283                          sizeof(struct tffs_name_table_entry) * (i + 1));
 284                 if (key_names->entries == NULL) {
 285                         fprintf(stderr, "ERROR: memory allocation failed!\n");
 286                         exit(EXIT_FAILURE);
 287                 }
 288                 name_item = &key_names->entries[i];
 289
 290                 name_item->id = read_uint32(names_entry->val, pos);
 291                 pos += sizeof(uint32_t);
 292                 name_item->val = strdup((const char *)(names_entry->val + pos));
 293
 294                 /*
 295                  * There is no "length" field because the string values are
 296                  * simply NULL-terminated -> strlen() gives us the size.
 297                  */
 298                 pos += get_walk_size(strlen(name_item->val) + 1);
 299
 300                 ++i;
 301         } while (pos < names_entry->len);
 302
 303         key_names->size = i;
 304 }
 305
 306 static void show_all_key_names(struct tffs_key_name_table *key_names)
 307 {
 308         for (uint32_t i = 0; i < key_names->size; i++)
 309                 printf("%s\n", key_names->entries[i].val);
 310 }
 311
 312 static int show_all_key_value_pairs(struct tffs_key_name_table *key_names)
 313 {
 314         uint8_t has_value = 0;
 315         struct tffs_entry tmp;
 316
 317         for (uint32_t i = 0; i < key_names->size; i++) {
 318                 if (find_entry(key_names->entries[i].id, &tmp)) {
 319                         printf("%s=", (const char *)key_names->entries[i].val);
 320                         print_entry_value(&tmp);
 321                         printf("\n");
 322                         has_value++;
 323                         free(tmp.val);
 324                 }
 325         }
 326
 327         if (!has_value) {
 328                 fprintf(stderr, "ERROR: no values found!\n");
 329                 return EXIT_FAILURE;
 330         }
 331
 332         return EXIT_SUCCESS;
 333 }
 334
 335 static int show_matching_key_value(struct tffs_key_name_table *key_names)
 336 {
 337         struct tffs_entry tmp;
 338         const char *name;
 339
 340         for (uint32_t i = 0; i < key_names->size; i++) {
 341                 name = key_names->entries[i].val;
 342
 343                 if (strncmp(name, name_filter, strlen(name)) == 0) {
 344                         if (find_entry(key_names->entries[i].id, &tmp)) {
 345                                 print_entry_value(&tmp);
 346                                 printf("\n");
 347                                 free(tmp.val);
 348                                 return EXIT_SUCCESS;
 349                         } else {
 350                                 fprintf(stderr,
 351                                         "ERROR: no value found for name %s!\n",
 352                                         name);
 353                                 return EXIT_FAILURE;
 354                         }
 355                 }
 356         }
 357
 358         fprintf(stderr, "ERROR: Unknown key name %s!\n", name_filter);
 359         return EXIT_FAILURE;
 360 }
 361
 362 static int check_sector(off_t pos)
 363 {
 364         if (!read_oob_sector_health) {
 365                 return 1;
 366         }
 367         if (read_sectoroob(pos)) {
 368                 return 0;
 369         }
 370         if (read_uint8(oobbuf, 0x00) != 0xff) {
 371                 /* block is bad */
 372                 return 0;
 373         }
 374         if (read_uint8(oobbuf, 0x01) != 0xff) {
 375                 /* sector is bad */
 376                 return 0;
 377         }
 378         return 1;
 379 }
 380
 381 static int check_block(off_t pos, uint32_t sector)
 382 {
 383         if (!check_sector(pos)) {
 384                 return 0;
 385         }
 386         if (read_sector(pos)) {
 387                 return 0;
 388         }
 389         if (read_uint64(readbuf, 0x00) != TFFS_BLOCK_HEADER_MAGIC) {
 390                 fprintf(stderr, "Warning: block without magic header. Skipping block\n");
 391                 return 0;
 392         }
 393         if (read_uint32(readbuf, 0x0c) != TFFS_SECTORS_PER_PAGE) {
 394                 fprintf(stderr, "Warning: block with wrong number of sectors per page. Skipping block\n");
 395                 return 0;
 396         }
 397
 398         uint32_t num_hdr_bad = read_uint32(readbuf, 0x0c);
 399         for (uint32_t i = 0; i < num_hdr_bad; i++) {
 400                 uint32_t bad = sector + read_uint64(readbuf, 0x1c + sizeof(uint64_t)*i);
 401                 sector_mark_bad(bad);
 402         }
 403
 404         return 1;
 405 }
 406
 407 static int scan_mtd(void)
 408 {
 409         struct mtd_info_user info;
 410
 411         if (ioctl(mtdfd, MEMGETINFO, &info)) {
 412                 return 0;
 413         }
 414
 415         blocksize = info.erasesize;
 416
 417         sectors = malloc(sizeof(*sectors) + (info.size / TFFS_SECTOR_SIZE + 7) / 8);
 418         if (sectors == NULL) {
 419                 fprintf(stderr, "ERROR: memory allocation failed!\n");
 420                 exit(EXIT_FAILURE);
 421         }
 422         sectors->num_sectors = info.size / TFFS_SECTOR_SIZE;
 423         memset(sectors->sectors, 0xff, (info.size / TFFS_SECTOR_SIZE + 7) / 8);
 424
 425         uint32_t sector = 0, valid_blocks = 0;
 426         uint8_t block_ok = 0;
 427         for (off_t pos = 0; pos < info.size; sector++, pos += TFFS_SECTOR_SIZE) {
 428                 if (pos % info.erasesize == 0) {
 429                         block_ok = check_block(pos, sector);
 430                         /* first sector of the block contains metadata
 431                            => handle it like a bad sector */
 432                         sector_mark_bad(sector);
 433                         if (block_ok) {
 434                                 valid_blocks++;
 435                         }
 436                 } else if (!block_ok || !sector_get_good(sector) || !check_sector(pos)) {
 437                         sector_mark_bad(sector);
 438                 }
 439         }
 440
 441         return valid_blocks;
 442 }
 443
 444 static void usage(int status)
 445 {
 446         FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
 447
 448         fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
 449         fprintf(stream,
 450         "\n"
 451         "Options:\n"
 452         "  -a              list all key value pairs found in the TFFS file/device\n"
 453         "  -d <mtd>        inspect the TFFS on mtd device <mtd>\n"
 454         "  -h              show this screen\n"
 455         "  -l              list all supported keys\n"
 456         "  -n <key name>   display the value of the given key\n"
 457         "  -o              read OOB information about sector health\n"
 458         );
 459
 460         exit(status);
 461 }
 462
 463 static void parse_options(int argc, char *argv[])
 464 {
 465         while (1) {
 466                 int c;
 467
 468                 c = getopt(argc, argv, "abd:hln:o");
 469                 if (c == -1)
 470                         break;
 471
 472                 switch (c) {
 473                 case 'a':
 474                         show_all = true;
 475                         name_filter = NULL;
 476                         print_all_key_names = false;
 477                         break;
 478                 case 'b':
 479                         swap_bytes = 1;
 480                         break;
 481                 case 'd':
 482                         mtddev = optarg;
 483                         break;
 484                 case 'h':
 485                         usage(EXIT_SUCCESS);
 486                         break;
 487                 case 'l':
 488                         print_all_key_names = true;
 489                         show_all = false;
 490                         name_filter = NULL;
 491                         break;
 492                 case 'n':
 493                         name_filter = optarg;
 494                         show_all = false;
 495                         print_all_key_names = false;
 496                         break;
 497                 case 'o':
 498                         read_oob_sector_health = true;
 499                         break;
 500                 default:
 501                         usage(EXIT_FAILURE);
 502                         break;
 503                 }
 504         }
 505
 506         if (!mtddev) {
 507                 fprintf(stderr, "ERROR: No input file (-d <file>) given!\n");
 508                 usage(EXIT_FAILURE);
 509         }
 510
 511         if (!show_all && !name_filter && !print_all_key_names) {
 512                 fprintf(stderr,
 513                         "ERROR: either -l, -a or -n <key name> is required!\n");
 514                 usage(EXIT_FAILURE);
 515         }
 516 }
 517
 518 int main(int argc, char *argv[])
 519 {
 520         int ret = EXIT_FAILURE;
 521         struct tffs_entry name_table;
 522         struct tffs_key_name_table key_names;
 523
 524         progname = basename(argv[0]);
 525
 526         parse_options(argc, argv);
 527
 528         mtdfd = open(mtddev, O_RDONLY);
 529         if (mtdfd < 0) {
 530                 fprintf(stderr, "ERROR: Failed to open tffs device %s\n",
 531                         mtddev);
 532                 goto out;
 533         }
 534
 535         if (!scan_mtd()) {
 536                 fprintf(stderr, "ERROR: Parsing blocks from tffs device %s failed\n", mtddev);
 537                 fprintf(stderr, "       Is byte-swapping (-b) required?\n");
 538                 goto out_close;
 539         }
 540
 541         if (!find_entry(TFFS_ID_TABLE_NAME, &name_table)) {
 542                 fprintf(stderr, "ERROR: No name table found on tffs device %s\n",
 543                         mtddev);
 544                 goto out_free_sectors;
 545         }
 546
 547         parse_key_names(&name_table, &key_names);
 548         if (key_names.size < 1) {
 549                 fprintf(stderr, "ERROR: No name table found on tffs device %s\n",
 550                         mtddev);
 551                 goto out_free_entry;
 552         }
 553
 554         if (print_all_key_names) {
 555                 show_all_key_names(&key_names);
 556                 ret = EXIT_SUCCESS;
 557         } else if (show_all) {
 558                 ret = show_all_key_value_pairs(&key_names);
 559         } else {
 560                 ret = show_matching_key_value(&key_names);
 561         }
 562
 563         free(key_names.entries);
 564 out_free_entry:
 565         free(name_table.val);
 566 out_free_sectors:
 567         free(sectors);
 568 out_close:
 569         close(mtdfd);
 570 out:
 571         return ret;
 572 }