tools/env/fw_env.c

   1 /*
   2  * (C) Copyright 2000-2010
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2008
   6  * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #define _GNU_SOURCE
  12
  13 #include <compiler.h>
  14 #include <errno.h>
  15 #include <env_flags.h>
  16 #include <fcntl.h>
  17 #include <linux/fs.h>
  18 #include <linux/stringify.h>
  19 #include <ctype.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stddef.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/ioctl.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28
  29 #ifdef MTD_OLD
  30 # include <stdint.h>
  31 # include <linux/mtd/mtd.h>
  32 #else
  33 # define  __user        /* nothing */
  34 # include <mtd/mtd-user.h>
  35 #endif
  36
  37 #include "fw_env_private.h"
  38 #include "fw_env.h"
  39
  40 struct env_opts default_opts = {
  41 #ifdef CONFIG_FILE
  42         .config_file = CONFIG_FILE
  43 #endif
  44 };
  45
  46 #define DIV_ROUND_UP(n, d)      (((n) + (d) - 1) / (d))
  47
  48 #define min(x, y) ({                            \
  49         typeof(x) _min1 = (x);                  \
  50         typeof(y) _min2 = (y);                  \
  51         (void) (&_min1 == &_min2);              \
  52         _min1 < _min2 ? _min1 : _min2; })
  53
  54 struct envdev_s {
  55         const char *devname;            /* Device name */
  56         long long devoff;               /* Device offset */
  57         ulong env_size;                 /* environment size */
  58         ulong erase_size;               /* device erase size */
  59         ulong env_sectors;              /* number of environment sectors */
  60         uint8_t mtd_type;               /* type of the MTD device */
  61 };
  62
  63 static struct envdev_s envdevices[2] =
  64 {
  65         {
  66                 .mtd_type = MTD_ABSENT,
  67         }, {
  68                 .mtd_type = MTD_ABSENT,
  69         },
  70 };
  71 static int dev_current;
  72
  73 #define DEVNAME(i)    envdevices[(i)].devname
  74 #define DEVOFFSET(i)  envdevices[(i)].devoff
  75 #define ENVSIZE(i)    envdevices[(i)].env_size
  76 #define DEVESIZE(i)   envdevices[(i)].erase_size
  77 #define ENVSECTORS(i) envdevices[(i)].env_sectors
  78 #define DEVTYPE(i)    envdevices[(i)].mtd_type
  79
  80 #define CUR_ENVSIZE ENVSIZE(dev_current)
  81
  82 static unsigned long usable_envsize;
  83 #define ENV_SIZE      usable_envsize
  84
  85 struct env_image_single {
  86         uint32_t        crc;    /* CRC32 over data bytes    */
  87         char            data[];
  88 };
  89
  90 struct env_image_redundant {
  91         uint32_t        crc;    /* CRC32 over data bytes    */
  92         unsigned char   flags;  /* active or obsolete */
  93         char            data[];
  94 };
  95
  96 enum flag_scheme {
  97         FLAG_NONE,
  98         FLAG_BOOLEAN,
  99         FLAG_INCREMENTAL,
 100 };
 101
 102 struct environment {
 103         void                    *image;
 104         uint32_t                *crc;
 105         unsigned char           *flags;
 106         char                    *data;
 107         enum flag_scheme        flag_scheme;
 108 };
 109
 110 static struct environment environment = {
 111         .flag_scheme = FLAG_NONE,
 112 };
 113
 114 static int env_aes_cbc_crypt(char *data, const int enc, uint8_t *key);
 115
 116 static int HaveRedundEnv = 0;
 117
 118 static unsigned char active_flag = 1;
 119 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
 120 static unsigned char obsolete_flag = 0;
 121
 122 #define DEFAULT_ENV_INSTANCE_STATIC
 123 #include <env_default.h>
 124
 125 static int flash_io (int mode);
 126 static int parse_config(struct env_opts *opts);
 127
 128 #if defined(CONFIG_FILE)
 129 static int get_config (char *);
 130 #endif
 131
 132 static char *skip_chars(char *s)
 133 {
 134         for (; *s != '\0'; s++) {
 135                 if (isblank(*s))
 136                         return s;
 137         }
 138         return NULL;
 139 }
 140
 141 static char *skip_blanks(char *s)
 142 {
 143         for (; *s != '\0'; s++) {
 144                 if (!isblank(*s))
 145                         return s;
 146         }
 147         return NULL;
 148 }
 149
 150 /*
 151  * s1 is either a simple 'name', or a 'name=value' pair.
 152  * s2 is a 'name=value' pair.
 153  * If the names match, return the value of s2, else NULL.
 154  */
 155 static char *envmatch(char *s1, char *s2)
 156 {
 157         if (s1 == NULL || s2 == NULL)
 158                 return NULL;
 159
 160         while (*s1 == *s2++)
 161                 if (*s1++ == '=')
 162                         return s2;
 163         if (*s1 == '\0' && *(s2 - 1) == '=')
 164                 return s2;
 165         return NULL;
 166 }
 167
 168 /**
 169  * Search the environment for a variable.
 170  * Return the value, if found, or NULL, if not found.
 171  */
 172 char *fw_getenv (char *name)
 173 {
 174         char *env, *nxt;
 175
 176         for (env = environment.data; *env; env = nxt + 1) {
 177                 char *val;
 178
 179                 for (nxt = env; *nxt; ++nxt) {
 180                         if (nxt >= &environment.data[ENV_SIZE]) {
 181                                 fprintf (stderr, "## Error: "
 182                                         "environment not terminated\n");
 183                                 return NULL;
 184                         }
 185                 }
 186                 val = envmatch (name, env);
 187                 if (!val)
 188                         continue;
 189                 return val;
 190         }
 191         return NULL;
 192 }
 193
 194 /*
 195  * Search the default environment for a variable.
 196  * Return the value, if found, or NULL, if not found.
 197  */
 198 char *fw_getdefenv(char *name)
 199 {
 200         char *env, *nxt;
 201
 202         for (env = default_environment; *env; env = nxt + 1) {
 203                 char *val;
 204
 205                 for (nxt = env; *nxt; ++nxt) {
 206                         if (nxt >= &default_environment[ENV_SIZE]) {
 207                                 fprintf(stderr, "## Error: "
 208                                         "default environment not terminated\n");
 209                                 return NULL;
 210                         }
 211                 }
 212                 val = envmatch(name, env);
 213                 if (!val)
 214                         continue;
 215                 return val;
 216         }
 217         return NULL;
 218 }
 219
 220 int parse_aes_key(char *key, uint8_t *bin_key)
 221 {
 222         char tmp[5] = { '0', 'x', 0, 0, 0 };
 223         unsigned long ul;
 224         int i;
 225
 226         if (strnlen(key, 64) != 32) {
 227                 fprintf(stderr,
 228                         "## Error: '-a' option requires 16-byte AES key\n");
 229                 return -1;
 230         }
 231
 232         for (i = 0; i < 16; i++) {
 233                 tmp[2] = key[0];
 234                 tmp[3] = key[1];
 235                 errno = 0;
 236                 ul = strtoul(tmp, NULL, 16);
 237                 if (errno) {
 238                         fprintf(stderr,
 239                                 "## Error: '-a' option requires valid AES key\n");
 240                         return -1;
 241                 }
 242                 bin_key[i] = ul & 0xff;
 243                 key += 2;
 244         }
 245         return 0;
 246 }
 247
 248 /*
 249  * Print the current definition of one, or more, or all
 250  * environment variables
 251  */
 252 int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
 253 {
 254         int i, rc = 0;
 255
 256         if (value_only && argc != 1) {
 257                 fprintf(stderr,
 258                         "## Error: `-n' option requires exactly one argument\n");
 259                 return -1;
 260         }
 261
 262         if (!opts)
 263                 opts = &default_opts;
 264
 265         if (fw_env_open(opts))
 266                 return -1;
 267
 268         if (argc == 0) {                /* Print all env variables  */
 269                 char *env, *nxt;
 270                 for (env = environment.data; *env; env = nxt + 1) {
 271                         for (nxt = env; *nxt; ++nxt) {
 272                                 if (nxt >= &environment.data[ENV_SIZE]) {
 273                                         fprintf (stderr, "## Error: "
 274                                                 "environment not terminated\n");
 275                                         return -1;
 276                                 }
 277                         }
 278
 279                         printf ("%s\n", env);
 280                 }
 281                 fw_env_close(opts);
 282                 return 0;
 283         }
 284
 285         for (i = 0; i < argc; ++i) {    /* print a subset of env variables */
 286                 char *name = argv[i];
 287                 char *val = NULL;
 288
 289                 val = fw_getenv(name);
 290                 if (!val) {
 291                         fprintf (stderr, "## Error: \"%s\" not defined\n", name);
 292                         rc = -1;
 293                         continue;
 294                 }
 295
 296                 if (value_only) {
 297                         puts(val);
 298                         break;
 299                 }
 300
 301                 printf("%s=%s\n", name, val);
 302         }
 303
 304         fw_env_close(opts);
 305
 306         return rc;
 307 }
 308
 309 int fw_env_flush(struct env_opts *opts)
 310 {
 311         int ret;
 312
 313         if (!opts)
 314                 opts = &default_opts;
 315
 316         if (opts->aes_flag) {
 317                 ret = env_aes_cbc_crypt(environment.data, 1,
 318                                         opts->aes_key);
 319                 if (ret) {
 320                         fprintf(stderr,
 321                                 "Error: can't encrypt env for flash\n");
 322                         return ret;
 323                 }
 324         }
 325
 326         /*
 327          * Update CRC
 328          */
 329         *environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
 330
 331         /* write environment back to flash */
 332         if (flash_io(O_RDWR)) {
 333                 fprintf(stderr,
 334                         "Error: can't write fw_env to flash\n");
 335                         return -1;
 336         }
 337
 338         return 0;
 339 }
 340
 341
 342 /*
 343  * Set/Clear a single variable in the environment.
 344  * This is called in sequence to update the environment
 345  * in RAM without updating the copy in flash after each set
 346  */
 347 int fw_env_write(char *name, char *value)
 348 {
 349         int len;
 350         char *env, *nxt;
 351         char *oldval = NULL;
 352         int deleting, creating, overwriting;
 353
 354         /*
 355          * search if variable with this name already exists
 356          */
 357         for (nxt = env = environment.data; *env; env = nxt + 1) {
 358                 for (nxt = env; *nxt; ++nxt) {
 359                         if (nxt >= &environment.data[ENV_SIZE]) {
 360                                 fprintf(stderr, "## Error: "
 361                                         "environment not terminated\n");
 362                                 errno = EINVAL;
 363                                 return -1;
 364                         }
 365                 }
 366                 if ((oldval = envmatch (name, env)) != NULL)
 367                         break;
 368         }
 369
 370         deleting = (oldval && !(value && strlen(value)));
 371         creating = (!oldval && (value && strlen(value)));
 372         overwriting = (oldval && (value && strlen(value)));
 373
 374         /* check for permission */
 375         if (deleting) {
 376                 if (env_flags_validate_varaccess(name,
 377                     ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
 378                         printf("Can't delete \"%s\"\n", name);
 379                         errno = EROFS;
 380                         return -1;
 381                 }
 382         } else if (overwriting) {
 383                 if (env_flags_validate_varaccess(name,
 384                     ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
 385                         printf("Can't overwrite \"%s\"\n", name);
 386                         errno = EROFS;
 387                         return -1;
 388                 } else if (env_flags_validate_varaccess(name,
 389                     ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
 390                         const char *defval = fw_getdefenv(name);
 391
 392                         if (defval == NULL)
 393                                 defval = "";
 394                         if (strcmp(oldval, defval)
 395                             != 0) {
 396                                 printf("Can't overwrite \"%s\"\n", name);
 397                                 errno = EROFS;
 398                                 return -1;
 399                         }
 400                 }
 401         } else if (creating) {
 402                 if (env_flags_validate_varaccess(name,
 403                     ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
 404                         printf("Can't create \"%s\"\n", name);
 405                         errno = EROFS;
 406                         return -1;
 407                 }
 408         } else
 409                 /* Nothing to do */
 410                 return 0;
 411
 412         if (deleting || overwriting) {
 413                 if (*++nxt == '\0') {
 414                         *env = '\0';
 415                 } else {
 416                         for (;;) {
 417                                 *env = *nxt++;
 418                                 if ((*env == '\0') && (*nxt == '\0'))
 419                                         break;
 420                                 ++env;
 421                         }
 422                 }
 423                 *++env = '\0';
 424         }
 425
 426         /* Delete only ? */
 427         if (!value || !strlen(value))
 428                 return 0;
 429
 430         /*
 431          * Append new definition at the end
 432          */
 433         for (env = environment.data; *env || *(env + 1); ++env);
 434         if (env > environment.data)
 435                 ++env;
 436         /*
 437          * Overflow when:
 438          * "name" + "=" + "val" +"\0\0"  > CUR_ENVSIZE - (env-environment)
 439          */
 440         len = strlen (name) + 2;
 441         /* add '=' for first arg, ' ' for all others */
 442         len += strlen(value) + 1;
 443
 444         if (len > (&environment.data[ENV_SIZE] - env)) {
 445                 fprintf (stderr,
 446                         "Error: environment overflow, \"%s\" deleted\n",
 447                         name);
 448                 return -1;
 449         }
 450
 451         while ((*env = *name++) != '\0')
 452                 env++;
 453         *env = '=';
 454         while ((*++env = *value++) != '\0')
 455                 ;
 456
 457         /* end is marked with double '\0' */
 458         *++env = '\0';
 459
 460         return 0;
 461 }
 462
 463 /*
 464  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
 465  * 0      - OK
 466  * EINVAL - need at least 1 argument
 467  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
 468  *          modified or deleted
 469  *
 470  */
 471 int fw_setenv(int argc, char *argv[], struct env_opts *opts)
 472 {
 473         int i;
 474         size_t len;
 475         char *name, **valv;
 476         char *value = NULL;
 477         int valc;
 478         int ret;
 479
 480         if (!opts)
 481                 opts = &default_opts;
 482
 483         if (argc < 1) {
 484                 fprintf(stderr, "## Error: variable name missing\n");
 485                 errno = EINVAL;
 486                 return -1;
 487         }
 488
 489         if (fw_env_open(opts)) {
 490                 fprintf(stderr, "Error: environment not initialized\n");
 491                 return -1;
 492         }
 493
 494         name = argv[0];
 495         valv = argv + 1;
 496         valc = argc - 1;
 497
 498         if (env_flags_validate_env_set_params(name, valv, valc) < 0) {
 499                 fw_env_close(opts);
 500                 return -1;
 501         }
 502
 503         len = 0;
 504         for (i = 0; i < valc; ++i) {
 505                 char *val = valv[i];
 506                 size_t val_len = strlen(val);
 507
 508                 if (value)
 509                         value[len - 1] = ' ';
 510                 value = realloc(value, len + val_len + 1);
 511                 if (!value) {
 512                         fprintf(stderr,
 513                                 "Cannot malloc %zu bytes: %s\n",
 514                                 len, strerror(errno));
 515                         return -1;
 516                 }
 517
 518                 memcpy(value + len, val, val_len);
 519                 len += val_len;
 520                 value[len++] = '\0';
 521         }
 522
 523         fw_env_write(name, value);
 524
 525         free(value);
 526
 527         ret = fw_env_flush(opts);
 528         fw_env_close(opts);
 529
 530         return ret;
 531 }
 532
 533 /*
 534  * Parse  a file  and configure the u-boot variables.
 535  * The script file has a very simple format, as follows:
 536  *
 537  * Each line has a couple with name, value:
 538  * <white spaces>variable_name<white spaces>variable_value
 539  *
 540  * Both variable_name and variable_value are interpreted as strings.
 541  * Any character after <white spaces> and before ending \r\n is interpreted
 542  * as variable's value (no comment allowed on these lines !)
 543  *
 544  * Comments are allowed if the first character in the line is #
 545  *
 546  * Returns -1 and sets errno error codes:
 547  * 0      - OK
 548  * -1     - Error
 549  */
 550 int fw_parse_script(char *fname, struct env_opts *opts)
 551 {
 552         FILE *fp;
 553         char dump[1024];        /* Maximum line length in the file */
 554         char *name;
 555         char *val;
 556         int lineno = 0;
 557         int len;
 558         int ret = 0;
 559
 560         if (!opts)
 561                 opts = &default_opts;
 562
 563         if (fw_env_open(opts)) {
 564                 fprintf(stderr, "Error: environment not initialized\n");
 565                 return -1;
 566         }
 567
 568         if (strcmp(fname, "-") == 0)
 569                 fp = stdin;
 570         else {
 571                 fp = fopen(fname, "r");
 572                 if (fp == NULL) {
 573                         fprintf(stderr, "I cannot open %s for reading\n",
 574                                  fname);
 575                         return -1;
 576                 }
 577         }
 578
 579         while (fgets(dump, sizeof(dump), fp)) {
 580                 lineno++;
 581                 len = strlen(dump);
 582
 583                 /*
 584                  * Read a whole line from the file. If the line is too long
 585                  * or is not terminated, reports an error and exit.
 586                  */
 587                 if (dump[len - 1] != '\n') {
 588                         fprintf(stderr,
 589                         "Line %d not corrected terminated or too long\n",
 590                                 lineno);
 591                         ret = -1;
 592                         break;
 593                 }
 594
 595                 /* Drop ending line feed / carriage return */
 596                 dump[--len] = '\0';
 597                 if (len && dump[len - 1] == '\r')
 598                         dump[--len] = '\0';
 599
 600                 /* Skip comment or empty lines */
 601                 if (len == 0 || dump[0] == '#')
 602                         continue;
 603
 604                 /*
 605                  * Search for variable's name,
 606                  * remove leading whitespaces
 607                  */
 608                 name = skip_blanks(dump);
 609                 if (!name)
 610                         continue;
 611
 612                 /* The first white space is the end of variable name */
 613                 val = skip_chars(name);
 614                 len = strlen(name);
 615                 if (val) {
 616                         *val++ = '\0';
 617                         if ((val - name) < len)
 618                                 val = skip_blanks(val);
 619                         else
 620                                 val = NULL;
 621                 }
 622
 623 #ifdef DEBUG
 624                 fprintf(stderr, "Setting %s : %s\n",
 625                         name, val ? val : " removed");
 626 #endif
 627
 628                 if (env_flags_validate_type(name, val) < 0) {
 629                         ret = -1;
 630                         break;
 631                 }
 632
 633                 /*
 634                  * If there is an error setting a variable,
 635                  * try to save the environment and returns an error
 636                  */
 637                 if (fw_env_write(name, val)) {
 638                         fprintf(stderr,
 639                         "fw_env_write returns with error : %s\n",
 640                                 strerror(errno));
 641                         ret = -1;
 642                         break;
 643                 }
 644
 645         }
 646
 647         /* Close file if not stdin */
 648         if (strcmp(fname, "-") != 0)
 649                 fclose(fp);
 650
 651         ret |= fw_env_flush(opts);
 652
 653         fw_env_close(opts);
 654
 655         return ret;
 656 }
 657
 658 /**
 659  * environment_end() - compute offset of first byte right after environemnt
 660  * @dev - index of enviroment buffer
 661  * Return:
 662  *  device offset of first byte right after environemnt
 663  */
 664 off_t environment_end(int dev)
 665 {
 666         /* environment is block aligned */
 667         return DEVOFFSET(dev) + ENVSECTORS(dev) * DEVESIZE(dev);
 668 }
 669
 670 /*
 671  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
 672  * 0    - block is good
 673  * > 0  - block is bad
 674  * < 0  - failed to test
 675  */
 676 static int flash_bad_block(int fd, uint8_t mtd_type, loff_t blockstart)
 677 {
 678         if (mtd_type == MTD_NANDFLASH) {
 679                 int badblock = ioctl(fd, MEMGETBADBLOCK, &blockstart);
 680
 681                 if (badblock < 0) {
 682                         perror ("Cannot read bad block mark");
 683                         return badblock;
 684                 }
 685
 686                 if (badblock) {
 687 #ifdef DEBUG
 688                         fprintf (stderr, "Bad block at 0x%llx, skipping\n",
 689                                 (unsigned long long)blockstart);
 690 #endif
 691                         return badblock;
 692                 }
 693         }
 694
 695         return 0;
 696 }
 697
 698 /*
 699  * Read data from flash at an offset into a provided buffer. On NAND it skips
 700  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
 701  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
 702  */
 703 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
 704                            off_t offset)
 705 {
 706         size_t blocklen;        /* erase / write length - one block on NAND,
 707                                    0 on NOR */
 708         size_t processed = 0;   /* progress counter */
 709         size_t readlen = count; /* current read length */
 710         off_t block_seek;       /* offset inside the current block to the start
 711                                    of the data */
 712         loff_t blockstart;      /* running start of the current block -
 713                                    MEMGETBADBLOCK needs 64 bits */
 714         int rc;
 715
 716         blockstart = (offset / DEVESIZE (dev)) * DEVESIZE (dev);
 717
 718         /* Offset inside a block */
 719         block_seek = offset - blockstart;
 720
 721         if (DEVTYPE(dev) == MTD_NANDFLASH) {
 722                 /*
 723                  * NAND: calculate which blocks we are reading. We have
 724                  * to read one block at a time to skip bad blocks.
 725                  */
 726                 blocklen = DEVESIZE (dev);
 727
 728                 /* Limit to one block for the first read */
 729                 if (readlen > blocklen - block_seek)
 730                         readlen = blocklen - block_seek;
 731         } else {
 732                 blocklen = 0;
 733         }
 734
 735         /* This only runs once on NOR flash */
 736         while (processed < count) {
 737                 rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
 738                 if (rc < 0)             /* block test failed */
 739                         return -1;
 740
 741                 if (blockstart + block_seek + readlen > environment_end(dev)) {
 742                         /* End of range is reached */
 743                         fprintf (stderr,
 744                                  "Too few good blocks within range\n");
 745                         return -1;
 746                 }
 747
 748                 if (rc) {               /* block is bad */
 749                         blockstart += blocklen;
 750                         continue;
 751                 }
 752
 753                 /*
 754                  * If a block is bad, we retry in the next block at the same
 755                  * offset - see common/env_nand.c::writeenv()
 756                  */
 757                 lseek (fd, blockstart + block_seek, SEEK_SET);
 758
 759                 rc = read (fd, buf + processed, readlen);
 760                 if (rc != readlen) {
 761                         fprintf (stderr, "Read error on %s: %s\n",
 762                                  DEVNAME (dev), strerror (errno));
 763                         return -1;
 764                 }
 765 #ifdef DEBUG
 766                 fprintf(stderr, "Read 0x%x bytes at 0x%llx on %s\n",
 767                         rc, (unsigned long long) blockstart + block_seek,
 768                         DEVNAME(dev));
 769 #endif
 770                 processed += readlen;
 771                 readlen = min (blocklen, count - processed);
 772                 block_seek = 0;
 773                 blockstart += blocklen;
 774         }
 775
 776         return processed;
 777 }
 778
 779 /*
 780  * Write count bytes from begin of environment, but stay within
 781  * ENVSECTORS(dev) sectors of
 782  * DEVOFFSET (dev). Similar to the read case above, on NOR and dataflash we
 783  * erase and write the whole data at once.
 784  */
 785 static int flash_write_buf(int dev, int fd, void *buf, size_t count)
 786 {
 787         void *data;
 788         struct erase_info_user erase;
 789         size_t blocklen;        /* length of NAND block / NOR erase sector */
 790         size_t erase_len;       /* whole area that can be erased - may include
 791                                    bad blocks */
 792         size_t erasesize;       /* erase / write length - one block on NAND,
 793                                    whole area on NOR */
 794         size_t processed = 0;   /* progress counter */
 795         size_t write_total;     /* total size to actually write - excluding
 796                                    bad blocks */
 797         off_t erase_offset;     /* offset to the first erase block (aligned)
 798                                    below offset */
 799         off_t block_seek;       /* offset inside the erase block to the start
 800                                    of the data */
 801         loff_t blockstart;      /* running start of the current block -
 802                                    MEMGETBADBLOCK needs 64 bits */
 803         int rc;
 804
 805         /*
 806          * For mtd devices only offset and size of the environment do matter
 807          */
 808         if (DEVTYPE(dev) == MTD_ABSENT) {
 809                 blocklen = count;
 810                 erase_len = blocklen;
 811                 blockstart = DEVOFFSET(dev);
 812                 block_seek = 0;
 813                 write_total = blocklen;
 814         } else {
 815                 blocklen = DEVESIZE(dev);
 816
 817                 erase_offset = DEVOFFSET(dev);
 818
 819                 /* Maximum area we may use */
 820                 erase_len = environment_end(dev) - erase_offset;
 821
 822                 blockstart = erase_offset;
 823
 824                 /* Offset inside a block */
 825                 block_seek = DEVOFFSET(dev) - erase_offset;
 826
 827                 /*
 828                  * Data size we actually write: from the start of the block
 829                  * to the start of the data, then count bytes of data, and
 830                  * to the end of the block
 831                  */
 832                 write_total = ((block_seek + count + blocklen - 1) /
 833                                                         blocklen) * blocklen;
 834         }
 835
 836         /*
 837          * Support data anywhere within erase sectors: read out the complete
 838          * area to be erased, replace the environment image, write the whole
 839          * block back again.
 840          */
 841         if (write_total > count) {
 842                 data = malloc (erase_len);
 843                 if (!data) {
 844                         fprintf (stderr,
 845                                  "Cannot malloc %zu bytes: %s\n",
 846                                  erase_len, strerror (errno));
 847                         return -1;
 848                 }
 849
 850                 rc = flash_read_buf(dev, fd, data, write_total, erase_offset);
 851                 if (write_total != rc)
 852                         return -1;
 853
 854 #ifdef DEBUG
 855                 fprintf(stderr, "Preserving data ");
 856                 if (block_seek != 0)
 857                         fprintf(stderr, "0x%x - 0x%lx", 0, block_seek - 1);
 858                 if (block_seek + count != write_total) {
 859                         if (block_seek != 0)
 860                                 fprintf(stderr, " and ");
 861                         fprintf(stderr, "0x%lx - 0x%lx",
 862                                 (unsigned long) block_seek + count,
 863                                 (unsigned long) write_total - 1);
 864                 }
 865                 fprintf(stderr, "\n");
 866 #endif
 867                 /* Overwrite the old environment */
 868                 memcpy (data + block_seek, buf, count);
 869         } else {
 870                 /*
 871                  * We get here, iff offset is block-aligned and count is a
 872                  * multiple of blocklen - see write_total calculation above
 873                  */
 874                 data = buf;
 875         }
 876
 877         if (DEVTYPE(dev) == MTD_NANDFLASH) {
 878                 /*
 879                  * NAND: calculate which blocks we are writing. We have
 880                  * to write one block at a time to skip bad blocks.
 881                  */
 882                 erasesize = blocklen;
 883         } else {
 884                 erasesize = erase_len;
 885         }
 886
 887         erase.length = erasesize;
 888
 889         /* This only runs once on NOR flash and SPI-dataflash */
 890         while (processed < write_total) {
 891                 rc = flash_bad_block(fd, DEVTYPE(dev), blockstart);
 892                 if (rc < 0)             /* block test failed */
 893                         return rc;
 894
 895                 if (blockstart + erasesize > environment_end(dev)) {
 896                         fprintf (stderr, "End of range reached, aborting\n");
 897                         return -1;
 898                 }
 899
 900                 if (rc) {               /* block is bad */
 901                         blockstart += blocklen;
 902                         continue;
 903                 }
 904
 905                 if (DEVTYPE(dev) != MTD_ABSENT) {
 906                         erase.start = blockstart;
 907                         ioctl(fd, MEMUNLOCK, &erase);
 908                         /* These do not need an explicit erase cycle */
 909                         if (DEVTYPE(dev) != MTD_DATAFLASH)
 910                                 if (ioctl(fd, MEMERASE, &erase) != 0) {
 911                                         fprintf(stderr,
 912                                                 "MTD erase error on %s: %s\n",
 913                                                 DEVNAME(dev), strerror(errno));
 914                                         return -1;
 915                                 }
 916                 }
 917
 918                 if (lseek (fd, blockstart, SEEK_SET) == -1) {
 919                         fprintf (stderr,
 920                                  "Seek error on %s: %s\n",
 921                                  DEVNAME (dev), strerror (errno));
 922                         return -1;
 923                 }
 924
 925 #ifdef DEBUG
 926                 fprintf(stderr, "Write 0x%llx bytes at 0x%llx\n",
 927                         (unsigned long long) erasesize,
 928                         (unsigned long long) blockstart);
 929 #endif
 930                 if (write (fd, data + processed, erasesize) != erasesize) {
 931                         fprintf (stderr, "Write error on %s: %s\n",
 932                                  DEVNAME (dev), strerror (errno));
 933                         return -1;
 934                 }
 935
 936                 if (DEVTYPE(dev) != MTD_ABSENT)
 937                         ioctl(fd, MEMLOCK, &erase);
 938
 939                 processed  += erasesize;
 940                 block_seek = 0;
 941                 blockstart += erasesize;
 942         }
 943
 944         if (write_total > count)
 945                 free (data);
 946
 947         return processed;
 948 }
 949
 950 /*
 951  * Set obsolete flag at offset - NOR flash only
 952  */
 953 static int flash_flag_obsolete (int dev, int fd, off_t offset)
 954 {
 955         int rc;
 956         struct erase_info_user erase;
 957
 958         erase.start  = DEVOFFSET (dev);
 959         erase.length = DEVESIZE (dev);
 960         /* This relies on the fact, that obsolete_flag == 0 */
 961         rc = lseek (fd, offset, SEEK_SET);
 962         if (rc < 0) {
 963                 fprintf (stderr, "Cannot seek to set the flag on %s \n",
 964                          DEVNAME (dev));
 965                 return rc;
 966         }
 967         ioctl (fd, MEMUNLOCK, &erase);
 968         rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
 969         ioctl (fd, MEMLOCK, &erase);
 970         if (rc < 0)
 971                 perror ("Could not set obsolete flag");
 972
 973         return rc;
 974 }
 975
 976 /* Encrypt or decrypt the environment before writing or reading it. */
 977 static int env_aes_cbc_crypt(char *payload, const int enc, uint8_t *key)
 978 {
 979         uint8_t *data = (uint8_t *)payload;
 980         const int len = usable_envsize;
 981         uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
 982         uint32_t aes_blocks;
 983
 984         /* First we expand the key. */
 985         aes_expand_key(key, key_exp);
 986
 987         /* Calculate the number of AES blocks to encrypt. */
 988         aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
 989
 990         if (enc)
 991                 aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks);
 992         else
 993                 aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks);
 994
 995         return 0;
 996 }
 997
 998 static int flash_write (int fd_current, int fd_target, int dev_target)
 999 {
1000         int rc;
1001
1002         switch (environment.flag_scheme) {
1003         case FLAG_NONE:
1004                 break;
1005         case FLAG_INCREMENTAL:
1006                 (*environment.flags)++;
1007                 break;
1008         case FLAG_BOOLEAN:
1009                 *environment.flags = active_flag;
1010                 break;
1011         default:
1012                 fprintf (stderr, "Unimplemented flash scheme %u \n",
1013                          environment.flag_scheme);
1014                 return -1;
1015         }
1016
1017 #ifdef DEBUG
1018         fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
1019                 DEVOFFSET (dev_target), DEVNAME (dev_target));
1020 #endif
1021
1022         rc = flash_write_buf(dev_target, fd_target, environment.image,
1023                              CUR_ENVSIZE);
1024         if (rc < 0)
1025                 return rc;
1026
1027         if (environment.flag_scheme == FLAG_BOOLEAN) {
1028                 /* Have to set obsolete flag */
1029                 off_t offset = DEVOFFSET (dev_current) +
1030                         offsetof (struct env_image_redundant, flags);
1031 #ifdef DEBUG
1032                 fprintf(stderr,
1033                         "Setting obsolete flag in environment at 0x%llx on %s\n",
1034                         DEVOFFSET (dev_current), DEVNAME (dev_current));
1035 #endif
1036                 flash_flag_obsolete (dev_current, fd_current, offset);
1037         }
1038
1039         return 0;
1040 }
1041
1042 static int flash_read (int fd)
1043 {
1044         int rc;
1045
1046         rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE,
1047                             DEVOFFSET(dev_current));
1048         if (rc != CUR_ENVSIZE)
1049                 return -1;
1050
1051         return 0;
1052 }
1053
1054 static int flash_io (int mode)
1055 {
1056         int fd_current, fd_target, rc, dev_target;
1057
1058         /* dev_current: fd_current, erase_current */
1059         fd_current = open (DEVNAME (dev_current), mode);
1060         if (fd_current < 0) {
1061                 fprintf (stderr,
1062                          "Can't open %s: %s\n",
1063                          DEVNAME (dev_current), strerror (errno));
1064                 return -1;
1065         }
1066
1067         if (mode == O_RDWR) {
1068                 if (HaveRedundEnv) {
1069                         /* switch to next partition for writing */
1070                         dev_target = !dev_current;
1071                         /* dev_target: fd_target, erase_target */
1072                         fd_target = open (DEVNAME (dev_target), mode);
1073                         if (fd_target < 0) {
1074                                 fprintf (stderr,
1075                                          "Can't open %s: %s\n",
1076                                          DEVNAME (dev_target),
1077                                          strerror (errno));
1078                                 rc = -1;
1079                                 goto exit;
1080                         }
1081                 } else {
1082                         dev_target = dev_current;
1083                         fd_target = fd_current;
1084                 }
1085
1086                 rc = flash_write (fd_current, fd_target, dev_target);
1087
1088                 if (HaveRedundEnv) {
1089                         if (close (fd_target)) {
1090                                 fprintf (stderr,
1091                                         "I/O error on %s: %s\n",
1092                                         DEVNAME (dev_target),
1093                                         strerror (errno));
1094                                 rc = -1;
1095                         }
1096                 }
1097         } else {
1098                 rc = flash_read (fd_current);
1099         }
1100
1101 exit:
1102         if (close (fd_current)) {
1103                 fprintf (stderr,
1104                          "I/O error on %s: %s\n",
1105                          DEVNAME (dev_current), strerror (errno));
1106                 return -1;
1107         }
1108
1109         return rc;
1110 }
1111
1112 /*
1113  * Prevent confusion if running from erased flash memory
1114  */
1115 int fw_env_open(struct env_opts *opts)
1116 {
1117         int crc0, crc0_ok;
1118         unsigned char flag0;
1119         void *addr0 = NULL;
1120
1121         int crc1, crc1_ok;
1122         unsigned char flag1;
1123         void *addr1 = NULL;
1124
1125         int ret;
1126
1127         struct env_image_single *single;
1128         struct env_image_redundant *redundant;
1129
1130         if (!opts)
1131                 opts = &default_opts;
1132
1133         if (parse_config(opts))         /* should fill envdevices */
1134                 return -EINVAL;
1135
1136         addr0 = calloc(1, CUR_ENVSIZE);
1137         if (addr0 == NULL) {
1138                 fprintf(stderr,
1139                         "Not enough memory for environment (%ld bytes)\n",
1140                         CUR_ENVSIZE);
1141                 ret = -ENOMEM;
1142                 goto open_cleanup;
1143         }
1144
1145         /* read environment from FLASH to local buffer */
1146         environment.image = addr0;
1147
1148         if (HaveRedundEnv) {
1149                 redundant = addr0;
1150                 environment.crc         = &redundant->crc;
1151                 environment.flags       = &redundant->flags;
1152                 environment.data        = redundant->data;
1153         } else {
1154                 single = addr0;
1155                 environment.crc         = &single->crc;
1156                 environment.flags       = NULL;
1157                 environment.data        = single->data;
1158         }
1159
1160         dev_current = 0;
1161         if (flash_io(O_RDONLY)) {
1162                 ret = -EIO;
1163                 goto open_cleanup;
1164         }
1165
1166         crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1167
1168         if (opts->aes_flag) {
1169                 ret = env_aes_cbc_crypt(environment.data, 0,
1170                                         opts->aes_key);
1171                 if (ret)
1172                         goto open_cleanup;
1173         }
1174
1175         crc0_ok = (crc0 == *environment.crc);
1176         if (!HaveRedundEnv) {
1177                 if (!crc0_ok) {
1178                         fprintf (stderr,
1179                                 "Warning: Bad CRC, using default environment\n");
1180                         memcpy(environment.data, default_environment, sizeof default_environment);
1181                 }
1182         } else {
1183                 flag0 = *environment.flags;
1184
1185                 dev_current = 1;
1186                 addr1 = calloc(1, CUR_ENVSIZE);
1187                 if (addr1 == NULL) {
1188                         fprintf(stderr,
1189                                 "Not enough memory for environment (%ld bytes)\n",
1190                                 CUR_ENVSIZE);
1191                         ret = -ENOMEM;
1192                         goto open_cleanup;
1193                 }
1194                 redundant = addr1;
1195
1196                 /*
1197                  * have to set environment.image for flash_read(), careful -
1198                  * other pointers in environment still point inside addr0
1199                  */
1200                 environment.image = addr1;
1201                 if (flash_io(O_RDONLY)) {
1202                         ret = -EIO;
1203                         goto open_cleanup;
1204                 }
1205
1206                 /* Check flag scheme compatibility */
1207                 if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1208                     DEVTYPE(!dev_current) == MTD_NORFLASH) {
1209                         environment.flag_scheme = FLAG_BOOLEAN;
1210                 } else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1211                            DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1212                         environment.flag_scheme = FLAG_INCREMENTAL;
1213                 } else if (DEVTYPE(dev_current) == MTD_DATAFLASH &&
1214                            DEVTYPE(!dev_current) == MTD_DATAFLASH) {
1215                         environment.flag_scheme = FLAG_BOOLEAN;
1216                 } else if (DEVTYPE(dev_current) == MTD_UBIVOLUME &&
1217                            DEVTYPE(!dev_current) == MTD_UBIVOLUME) {
1218                         environment.flag_scheme = FLAG_INCREMENTAL;
1219                 } else if (DEVTYPE(dev_current) == MTD_ABSENT &&
1220                            DEVTYPE(!dev_current) == MTD_ABSENT) {
1221                         environment.flag_scheme = FLAG_INCREMENTAL;
1222                 } else {
1223                         fprintf (stderr, "Incompatible flash types!\n");
1224                         ret = -EINVAL;
1225                         goto open_cleanup;
1226                 }
1227
1228                 crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1229
1230                 if (opts->aes_flag) {
1231                         ret = env_aes_cbc_crypt(redundant->data, 0,
1232                                                 opts->aes_key);
1233                         if (ret)
1234                                 goto open_cleanup;
1235                 }
1236
1237                 crc1_ok = (crc1 == redundant->crc);
1238                 flag1 = redundant->flags;
1239
1240                 if (crc0_ok && !crc1_ok) {
1241                         dev_current = 0;
1242                 } else if (!crc0_ok && crc1_ok) {
1243                         dev_current = 1;
1244                 } else if (!crc0_ok && !crc1_ok) {
1245                         fprintf (stderr,
1246                                 "Warning: Bad CRC, using default environment\n");
1247                         memcpy (environment.data, default_environment,
1248                                 sizeof default_environment);
1249                         dev_current = 0;
1250                 } else {
1251                         switch (environment.flag_scheme) {
1252                         case FLAG_BOOLEAN:
1253                                 if (flag0 == active_flag &&
1254                                     flag1 == obsolete_flag) {
1255                                         dev_current = 0;
1256                                 } else if (flag0 == obsolete_flag &&
1257                                            flag1 == active_flag) {
1258                                         dev_current = 1;
1259                                 } else if (flag0 == flag1) {
1260                                         dev_current = 0;
1261                                 } else if (flag0 == 0xFF) {
1262                                         dev_current = 0;
1263                                 } else if (flag1 == 0xFF) {
1264                                         dev_current = 1;
1265                                 } else {
1266                                         dev_current = 0;
1267                                 }
1268                                 break;
1269                         case FLAG_INCREMENTAL:
1270                                 if (flag0 == 255 && flag1 == 0)
1271                                         dev_current = 1;
1272                                 else if ((flag1 == 255 && flag0 == 0) ||
1273                                          flag0 >= flag1)
1274                                         dev_current = 0;
1275                                 else /* flag1 > flag0 */
1276                                         dev_current = 1;
1277                                 break;
1278                         default:
1279                                 fprintf (stderr, "Unknown flag scheme %u \n",
1280                                          environment.flag_scheme);
1281                                 return -1;
1282                         }
1283                 }
1284
1285                 /*
1286                  * If we are reading, we don't need the flag and the CRC any
1287                  * more, if we are writing, we will re-calculate CRC and update
1288                  * flags before writing out
1289                  */
1290                 if (dev_current) {
1291                         environment.image       = addr1;
1292                         environment.crc         = &redundant->crc;
1293                         environment.flags       = &redundant->flags;
1294                         environment.data        = redundant->data;
1295                         free (addr0);
1296                 } else {
1297                         environment.image       = addr0;
1298                         /* Other pointers are already set */
1299                         free (addr1);
1300                 }
1301 #ifdef DEBUG
1302                 fprintf(stderr, "Selected env in %s\n", DEVNAME(dev_current));
1303 #endif
1304         }
1305         return 0;
1306
1307 open_cleanup:
1308         if (addr0)
1309                 free(addr0);
1310
1311         if (addr1)
1312                 free(addr0);
1313
1314         return ret;
1315 }
1316
1317 /*
1318  * Simply free allocated buffer with environment
1319  */
1320 int fw_env_close(struct env_opts *opts)
1321 {
1322         if (environment.image)
1323                 free(environment.image);
1324
1325         environment.image = NULL;
1326
1327         return 0;
1328 }
1329
1330 static int check_device_config(int dev)
1331 {
1332         struct stat st;
1333         int fd, rc = 0;
1334
1335         fd = open(DEVNAME(dev), O_RDONLY);
1336         if (fd < 0) {
1337                 fprintf(stderr,
1338                         "Cannot open %s: %s\n",
1339                         DEVNAME(dev), strerror(errno));
1340                 return -1;
1341         }
1342
1343         rc = fstat(fd, &st);
1344         if (rc < 0) {
1345                 fprintf(stderr, "Cannot stat the file %s\n",
1346                         DEVNAME(dev));
1347                 goto err;
1348         }
1349
1350         if (S_ISCHR(st.st_mode)) {
1351                 struct mtd_info_user mtdinfo;
1352                 rc = ioctl(fd, MEMGETINFO, &mtdinfo);
1353                 if (rc < 0) {
1354                         fprintf(stderr, "Cannot get MTD information for %s\n",
1355                                 DEVNAME(dev));
1356                         goto err;
1357                 }
1358                 if (mtdinfo.type != MTD_NORFLASH &&
1359                     mtdinfo.type != MTD_NANDFLASH &&
1360                     mtdinfo.type != MTD_DATAFLASH &&
1361                     mtdinfo.type != MTD_UBIVOLUME) {
1362                         fprintf(stderr, "Unsupported flash type %u on %s\n",
1363                                 mtdinfo.type, DEVNAME(dev));
1364                         goto err;
1365                 }
1366                 DEVTYPE(dev) = mtdinfo.type;
1367                 if (DEVESIZE(dev) == 0)
1368                         /* Assume the erase size is the same as the env-size */
1369                         DEVESIZE(dev) = ENVSIZE(dev);
1370         } else {
1371                 uint64_t size;
1372                 DEVTYPE(dev) = MTD_ABSENT;
1373                 if (DEVESIZE(dev) == 0)
1374                         /* Assume the erase size to be 512 bytes */
1375                         DEVESIZE(dev) = 0x200;
1376
1377                 /*
1378                  * Check for negative offsets, treat it as backwards offset
1379                  * from the end of the block device
1380                  */
1381                 if (DEVOFFSET(dev) < 0) {
1382                         rc = ioctl(fd, BLKGETSIZE64, &size);
1383                         if (rc < 0) {
1384                                 fprintf(stderr, "Could not get block device size on %s\n",
1385                                         DEVNAME(dev));
1386                                 goto err;
1387                         }
1388
1389                         DEVOFFSET(dev) = DEVOFFSET(dev) + size;
1390 #ifdef DEBUG
1391                         fprintf(stderr, "Calculated device offset 0x%llx on %s\n",
1392                                 DEVOFFSET(dev), DEVNAME(dev));
1393 #endif
1394                 }
1395         }
1396
1397         if (ENVSECTORS(dev) == 0)
1398                 /* Assume enough sectors to cover the environment */
1399                 ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
1400
1401         if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
1402                 fprintf(stderr, "Environment does not start on (erase) block boundary\n");
1403                 errno = EINVAL;
1404                 return -1;
1405         }
1406
1407         if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
1408                 fprintf(stderr, "Environment does not fit into available sectors\n");
1409                 errno = EINVAL;
1410                 return -1;
1411         }
1412
1413 err:
1414         close(fd);
1415         return rc;
1416 }
1417
1418 static int parse_config(struct env_opts *opts)
1419 {
1420         int rc;
1421
1422         if (!opts)
1423                 opts = &default_opts;
1424
1425 #if defined(CONFIG_FILE)
1426         /* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1427         if (get_config(opts->config_file)) {
1428                 fprintf(stderr, "Cannot parse config file '%s': %m\n",
1429                         opts->config_file);
1430                 return -1;
1431         }
1432 #else
1433         DEVNAME (0) = DEVICE1_NAME;
1434         DEVOFFSET (0) = DEVICE1_OFFSET;
1435         ENVSIZE (0) = ENV1_SIZE;
1436
1437         /* Set defaults for DEVESIZE, ENVSECTORS later once we
1438          * know DEVTYPE
1439          */
1440 #ifdef DEVICE1_ESIZE
1441         DEVESIZE (0) = DEVICE1_ESIZE;
1442 #endif
1443 #ifdef DEVICE1_ENVSECTORS
1444         ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1445 #endif
1446
1447 #ifdef HAVE_REDUND
1448         DEVNAME (1) = DEVICE2_NAME;
1449         DEVOFFSET (1) = DEVICE2_OFFSET;
1450         ENVSIZE (1) = ENV2_SIZE;
1451
1452         /* Set defaults for DEVESIZE, ENVSECTORS later once we
1453          * know DEVTYPE
1454          */
1455 #ifdef DEVICE2_ESIZE
1456         DEVESIZE (1) = DEVICE2_ESIZE;
1457 #endif
1458 #ifdef DEVICE2_ENVSECTORS
1459         ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1460 #endif
1461         HaveRedundEnv = 1;
1462 #endif
1463 #endif
1464         rc = check_device_config(0);
1465         if (rc < 0)
1466                 return rc;
1467
1468         if (HaveRedundEnv) {
1469                 rc = check_device_config(1);
1470                 if (rc < 0)
1471                         return rc;
1472
1473                 if (ENVSIZE(0) != ENVSIZE(1)) {
1474                         fprintf(stderr,
1475                                 "Redundant environments have unequal size");
1476                         return -1;
1477                 }
1478         }
1479
1480         usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
1481         if (HaveRedundEnv)
1482                 usable_envsize -= sizeof(char);
1483
1484         if (opts->aes_flag)
1485                 usable_envsize &= ~(AES_KEY_LENGTH - 1);
1486
1487         return 0;
1488 }
1489
1490 #if defined(CONFIG_FILE)
1491 static int get_config (char *fname)
1492 {
1493         FILE *fp;
1494         int i = 0;
1495         int rc;
1496         char dump[128];
1497         char *devname;
1498
1499         fp = fopen (fname, "r");
1500         if (fp == NULL)
1501                 return -1;
1502
1503         while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1504                 /* Skip incomplete conversions and comment strings */
1505                 if (dump[0] == '#')
1506                         continue;
1507
1508                 rc = sscanf(dump, "%ms %lli %lx %lx %lx",
1509                             &devname,
1510                             &DEVOFFSET(i),
1511                             &ENVSIZE(i),
1512                             &DEVESIZE(i),
1513                             &ENVSECTORS(i));
1514
1515                 if (rc < 3)
1516                         continue;
1517
1518                 DEVNAME(i) = devname;
1519
1520                 /* Set defaults for DEVESIZE, ENVSECTORS later once we
1521                  * know DEVTYPE
1522                  */
1523
1524                 i++;
1525         }
1526         fclose (fp);
1527
1528         HaveRedundEnv = i - 1;
1529         if (!i) {                       /* No valid entries found */
1530                 errno = EINVAL;
1531                 return -1;
1532         } else
1533                 return 0;
1534 }
1535 #endif