misc-utils/wipefs.c

   1 /*
   2  * wipefs - utility to wipe filesystems from device
   3  *
   4  * Copyright (C) 2009 Red Hat, Inc. All rights reserved.
   5  * Written by Karel Zak <kzak@redhat.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it would be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21 #include <sys/stat.h>
  22 #include <sys/types.h>
  23 #include <ctype.h>
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <getopt.h>
  30 #include <string.h>
  31 #include <limits.h>
  32
  33 #include <blkid.h>
  34
  35 #include "nls.h"
  36 #include "xalloc.h"
  37 #include "strutils.h"
  38 #include "all-io.h"
  39 #include "match.h"
  40 #include "c.h"
  41 #include "closestream.h"
  42 #include "optutils.h"
  43 #include "blkdev.h"
  44
  45 struct wipe_desc {
  46         loff_t          offset;         /* magic string offset */
  47         size_t          len;            /* length of magic string */
  48         unsigned char   *magic;         /* magic string */
  49
  50         char            *usage;         /* raid, filesystem, ... */
  51         char            *type;          /* FS type */
  52         char            *label;         /* FS label */
  53         char            *uuid;          /* FS uuid */
  54
  55         struct wipe_desc        *next;
  56
  57         unsigned int    zap : 1,
  58                         on_disk : 1,
  59                         is_parttable : 1;
  60
  61 };
  62
  63 enum {
  64         WP_MODE_PRETTY,         /* default */
  65         WP_MODE_PARSABLE
  66 };
  67
  68 enum {
  69         WP_FL_NOACT     = (1 << 1),
  70         WP_FL_ALL       = (1 << 2),
  71         WP_FL_QUIET     = (1 << 3),
  72         WP_FL_BACKUP    = (1 << 4),
  73         WP_FL_FORCE     = (1 << 5)
  74 };
  75
  76 static const char *type_pattern;
  77
  78 static void
  79 print_pretty(struct wipe_desc *wp, int line)
  80 {
  81         if (!line) {
  82                 printf("offset               type\n");
  83                 printf("----------------------------------------------------------------\n");
  84         }
  85
  86         printf("0x%-17jx  %s   [%s]", wp->offset, wp->type, _(wp->usage));
  87
  88         if (wp->label && *wp->label)
  89                 printf("\n%27s %s", "LABEL:", wp->label);
  90         if (wp->uuid)
  91                 printf("\n%27s %s", "UUID: ", wp->uuid);
  92         puts("\n");
  93 }
  94
  95 static void
  96 print_parsable(struct wipe_desc *wp, int line)
  97 {
  98         char enc[256];
  99
 100         if (!line)
 101                 printf("# offset,uuid,label,type\n");
 102
 103         printf("0x%jx,", wp->offset);
 104
 105         if (wp->uuid) {
 106                 blkid_encode_string(wp->uuid, enc, sizeof(enc));
 107                 printf("%s,", enc);
 108         } else
 109                 fputc(',', stdout);
 110
 111         if (wp->label) {
 112                 blkid_encode_string(wp->label, enc, sizeof(enc));
 113                 printf("%s,", enc);
 114         } else
 115                 fputc(',', stdout);
 116
 117         blkid_encode_string(wp->type, enc, sizeof(enc));
 118         printf("%s\n", enc);
 119 }
 120
 121 static void
 122 print_all(struct wipe_desc *wp, int mode)
 123 {
 124         int n = 0;
 125
 126         while (wp) {
 127                 switch (mode) {
 128                 case WP_MODE_PRETTY:
 129                         print_pretty(wp, n++);
 130                         break;
 131                 case WP_MODE_PARSABLE:
 132                         print_parsable(wp, n++);
 133                         break;
 134                 default:
 135                         abort();
 136                 }
 137                 wp = wp->next;
 138         }
 139 }
 140
 141 static struct wipe_desc *
 142 add_offset(struct wipe_desc *wp0, loff_t offset, int zap)
 143 {
 144         struct wipe_desc *wp = wp0;
 145
 146         while (wp) {
 147                 if (wp->offset == offset)
 148                         return wp;
 149                 wp = wp->next;
 150         }
 151
 152         wp = xcalloc(1, sizeof(struct wipe_desc));
 153         wp->offset = offset;
 154         wp->next = wp0;
 155         wp->zap = zap ? 1 : 0;
 156         return wp;
 157 }
 158
 159 static struct wipe_desc *
 160 clone_offset(struct wipe_desc *wp0)
 161 {
 162         struct wipe_desc *wp = NULL;
 163
 164         while(wp0) {
 165                 wp = add_offset(wp, wp0->offset, wp0->zap);
 166                 wp0 = wp0->next;
 167         }
 168
 169         return wp;
 170 }
 171
 172 static struct wipe_desc *
 173 get_desc_for_probe(struct wipe_desc *wp, blkid_probe pr)
 174 {
 175         const char *off, *type, *mag, *p, *usage = NULL;
 176         size_t len;
 177         loff_t offset;
 178         int rc, ispt = 0;
 179
 180         /* superblocks */
 181         if (blkid_probe_lookup_value(pr, "TYPE", &type, NULL) == 0) {
 182                 rc = blkid_probe_lookup_value(pr, "SBMAGIC_OFFSET", &off, NULL);
 183                 if (!rc)
 184                         rc = blkid_probe_lookup_value(pr, "SBMAGIC", &mag, &len);
 185                 if (rc)
 186                         return wp;
 187
 188         /* partitions */
 189         } else if (blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL) == 0) {
 190                 rc = blkid_probe_lookup_value(pr, "PTMAGIC_OFFSET", &off, NULL);
 191                 if (!rc)
 192                         rc = blkid_probe_lookup_value(pr, "PTMAGIC", &mag, &len);
 193                 if (rc)
 194                         return wp;
 195                 usage = N_("partition table");
 196                 ispt = 1;
 197         } else
 198                 return wp;
 199
 200         if (type_pattern && !match_fstype(type, type_pattern))
 201                 return wp;
 202
 203         offset = strtoll(off, NULL, 10);
 204
 205         wp = add_offset(wp, offset, 0);
 206         if (!wp)
 207                 return NULL;
 208
 209         if (usage || blkid_probe_lookup_value(pr, "USAGE", &usage, NULL) == 0)
 210                 wp->usage = xstrdup(usage);
 211
 212         wp->type = xstrdup(type);
 213         wp->on_disk = 1;
 214         wp->is_parttable = ispt ? 1 : 0;
 215
 216         wp->magic = xmalloc(len);
 217         memcpy(wp->magic, mag, len);
 218         wp->len = len;
 219
 220         if (blkid_probe_lookup_value(pr, "LABEL", &p, NULL) == 0)
 221                 wp->label = xstrdup(p);
 222
 223         if (blkid_probe_lookup_value(pr, "UUID", &p, NULL) == 0)
 224                 wp->uuid = xstrdup(p);
 225
 226         return wp;
 227 }
 228
 229 static blkid_probe
 230 new_probe(const char *devname, int mode)
 231 {
 232         blkid_probe pr = NULL;
 233
 234         if (!devname)
 235                 return NULL;
 236
 237         if (mode) {
 238                 int fd = open(devname, mode);
 239                 if (fd < 0)
 240                         goto error;
 241
 242                 pr = blkid_new_probe();
 243                 if (!pr || blkid_probe_set_device(pr, fd, 0, 0) != 0) {
 244                         close(fd);
 245                         goto error;
 246                 }
 247         } else
 248                 pr = blkid_new_probe_from_filename(devname);
 249
 250         if (!pr)
 251                 goto error;
 252
 253         blkid_probe_enable_superblocks(pr, 1);
 254         blkid_probe_set_superblocks_flags(pr,
 255                         BLKID_SUBLKS_MAGIC |    /* return magic string and offset */
 256                         BLKID_SUBLKS_TYPE |     /* return superblock type */
 257                         BLKID_SUBLKS_USAGE |    /* return USAGE= */
 258                         BLKID_SUBLKS_LABEL |    /* return LABEL= */
 259                         BLKID_SUBLKS_UUID |     /* return UUID= */
 260                         BLKID_SUBLKS_BADCSUM);  /* accept bad checksums */
 261
 262         blkid_probe_enable_partitions(pr, 1);
 263         blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC);
 264
 265         return pr;
 266 error:
 267         blkid_free_probe(pr);
 268         err(EXIT_FAILURE, _("error: %s: probing initialization failed"), devname);
 269 }
 270
 271 static struct wipe_desc *
 272 read_offsets(struct wipe_desc *wp, const char *devname)
 273 {
 274         blkid_probe pr = new_probe(devname, 0);
 275
 276         if (!pr)
 277                 return NULL;
 278
 279         while (blkid_do_probe(pr) == 0) {
 280                 wp = get_desc_for_probe(wp, pr);
 281                 if (!wp)
 282                         break;
 283         }
 284
 285         blkid_free_probe(pr);
 286         return wp;
 287 }
 288
 289 static void
 290 free_wipe(struct wipe_desc *wp)
 291 {
 292         while (wp) {
 293                 struct wipe_desc *next = wp->next;
 294
 295                 free(wp->usage);
 296                 free(wp->type);
 297                 free(wp->magic);
 298                 free(wp->label);
 299                 free(wp->uuid);
 300                 free(wp);
 301
 302                 wp = next;
 303         }
 304 }
 305
 306 static void do_wipe_real(blkid_probe pr, const char *devname,
 307                         struct wipe_desc *w, int flags)
 308 {
 309         size_t i;
 310
 311         if (blkid_do_wipe(pr, (flags & WP_FL_NOACT) != 0))
 312                 warn(_("%s: failed to erase %s magic string at offset 0x%08jx"),
 313                      devname, w->type, w->offset);
 314
 315         if (flags & WP_FL_QUIET)
 316                 return;
 317
 318         printf(P_("%s: %zd byte was erased at offset 0x%08jx (%s): ",
 319                   "%s: %zd bytes were erased at offset 0x%08jx (%s): ",
 320                   w->len),
 321                devname, w->len, w->offset, w->type);
 322
 323         for (i = 0; i < w->len; i++) {
 324                 printf("%02x", w->magic[i]);
 325                 if (i + 1 < w->len)
 326                         fputc(' ', stdout);
 327         }
 328         putchar('\n');
 329 }
 330
 331 static void do_backup(struct wipe_desc *wp, const char *base)
 332 {
 333         char *fname = NULL;
 334         int fd;
 335
 336         xasprintf(&fname, "%s0x%08jx.bak", base, wp->offset);
 337
 338         fd = open(fname, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
 339         if (fd < 0)
 340                 goto err;
 341         if (write_all(fd, wp->magic, wp->len) != 0)
 342                 goto err;
 343         close(fd);
 344         free(fname);
 345         return;
 346 err:
 347         err(EXIT_FAILURE, _("%s: failed to create a signature backup"), fname);
 348 }
 349
 350 static void rereadpt(int fd, const char *devname)
 351 {
 352 #ifdef BLKRRPART
 353         struct stat st;
 354
 355         if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
 356                 return;
 357
 358         errno = 0;
 359         ioctl(fd, BLKRRPART);
 360         printf(_("%s: calling ioctl to re-read partition table: %m\n"), devname);
 361 #endif
 362 }
 363
 364 static struct wipe_desc *
 365 do_wipe(struct wipe_desc *wp, const char *devname, int flags)
 366 {
 367         int mode = O_RDWR, reread = 0, need_force = 0;
 368         blkid_probe pr;
 369         struct wipe_desc *w, *wp0;
 370         int zap = (flags & WP_FL_ALL) ? 1 : wp->zap;
 371         char *backup = NULL;
 372
 373         if (!(flags & WP_FL_FORCE))
 374                 mode |= O_EXCL;
 375         pr = new_probe(devname, mode);
 376         if (!pr)
 377                 return NULL;
 378
 379         if (zap && (flags & WP_FL_BACKUP)) {
 380                 const char *home = getenv ("HOME");
 381                 if (!home)
 382                         errx(EXIT_FAILURE, _("failed to create a signature backup, $HOME undefined"));
 383                 xasprintf (&backup, "%s/wipefs-%s-", home, basename(devname));
 384         }
 385
 386         wp0 = clone_offset(wp);
 387
 388         while (blkid_do_probe(pr) == 0) {
 389                 wp = get_desc_for_probe(wp, pr);
 390                 if (!wp)
 391                         break;
 392
 393                 /* Check if offset is in provided list */
 394                 w = wp0;
 395                 while(w && w->offset != wp->offset)
 396                         w = w->next;
 397                 if (wp0 && !w)
 398                         continue;
 399
 400                 /* Mark done if found in provided list */
 401                 if (w)
 402                         w->on_disk = wp->on_disk;
 403
 404                 if (!wp->on_disk)
 405                         continue;
 406
 407                 if (!(flags & WP_FL_FORCE)
 408                     && wp->is_parttable
 409                     && !blkid_probe_is_wholedisk(pr)) {
 410                         warnx(_("%s: ignoring nested \"%s\" partition table "
 411                                 "on non-whole disk device"), devname, wp->type);
 412                         need_force = 1;
 413                         continue;
 414                 }
 415
 416                 if (zap) {
 417                         if (backup)
 418                                 do_backup(wp, backup);
 419                         do_wipe_real(pr, devname, wp, flags);
 420                         if (wp->is_parttable)
 421                                 reread = 1;
 422                 }
 423         }
 424
 425         for (w = wp0; w != NULL; w = w->next) {
 426                 if (!w->on_disk && !(flags & WP_FL_QUIET))
 427                         warnx(_("%s: offset 0x%jx not found"), devname, w->offset);
 428         }
 429
 430         if (need_force)
 431                 warnx(_("Use the --force option to force erase."));
 432
 433         fsync(blkid_probe_get_fd(pr));
 434
 435         if (reread && (mode & O_EXCL))
 436                 rereadpt(blkid_probe_get_fd(pr), devname);
 437
 438         close(blkid_probe_get_fd(pr));
 439         blkid_free_probe(pr);
 440         free_wipe(wp0);
 441         free(backup);
 442
 443         return wp;
 444 }
 445
 446
 447 static void __attribute__((__noreturn__))
 448 usage(FILE *out)
 449 {
 450         fputs(USAGE_HEADER, out);
 451         fprintf(out,
 452               _(" %s [options] <device>\n"), program_invocation_short_name);
 453
 454         fputs(USAGE_SEPARATOR, out);
 455         fputs(_("Wipe signatures from a device.\n"), out);
 456
 457         fputs(USAGE_OPTIONS, out);
 458         fputs(_(" -a, --all           wipe all magic strings (BE CAREFUL!)\n"
 459                 " -b, --backup        create a signature backup in $HOME\n"
 460                 " -f, --force         force erasure\n"
 461                 " -h, --help          show this help text\n"
 462                 " -n, --no-act        do everything except the actual write() call\n"
 463                 " -o, --offset <num>  offset to erase, in bytes\n"
 464                 " -p, --parsable      print out in parsable instead of printable format\n"
 465                 " -q, --quiet         suppress output messages\n"
 466                 " -t, --types <list>  limit the set of filesystem, RAIDs or partition tables\n"
 467                 " -V, --version       output version information and exit\n"), out);
 468
 469         fprintf(out, USAGE_MAN_TAIL("wipefs(8)"));
 470
 471         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 472 }
 473
 474
 475 int
 476 main(int argc, char **argv)
 477 {
 478         struct wipe_desc *wp0 = NULL, *wp;
 479         int c, has_offset = 0, flags = 0;
 480         int mode = WP_MODE_PRETTY;
 481
 482         static const struct option longopts[] = {
 483             { "all",       0, 0, 'a' },
 484             { "backup",    0, 0, 'b' },
 485             { "force",     0, 0, 'f' },
 486             { "help",      0, 0, 'h' },
 487             { "no-act",    0, 0, 'n' },
 488             { "offset",    1, 0, 'o' },
 489             { "parsable",  0, 0, 'p' },
 490             { "quiet",     0, 0, 'q' },
 491             { "types",     1, 0, 't' },
 492             { "version",   0, 0, 'V' },
 493             { NULL,        0, 0, 0 }
 494         };
 495
 496         static const ul_excl_t excl[] = {       /* rows and cols in in ASCII order */
 497                 { 'a','o' },
 498                 { 0 }
 499         };
 500         int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
 501
 502         setlocale(LC_ALL, "");
 503         bindtextdomain(PACKAGE, LOCALEDIR);
 504         textdomain(PACKAGE);
 505         atexit(close_stdout);
 506
 507         while ((c = getopt_long(argc, argv, "abfhno:pqt:V", longopts, NULL)) != -1) {
 508
 509                 err_exclusive_options(c, longopts, excl, excl_st);
 510
 511                 switch(c) {
 512                 case 'a':
 513                         flags |= WP_FL_ALL;
 514                         break;
 515                 case 'b':
 516                         flags |= WP_FL_BACKUP;
 517                         break;
 518                 case 'f':
 519                         flags |= WP_FL_FORCE;
 520                         break;
 521                 case 'h':
 522                         usage(stdout);
 523                         break;
 524                 case 'n':
 525                         flags |= WP_FL_NOACT;
 526                         break;
 527                 case 'o':
 528                         wp0 = add_offset(wp0, strtosize_or_err(optarg,
 529                                          _("invalid offset argument")), 1);
 530                         has_offset++;
 531                         break;
 532                 case 'p':
 533                         mode = WP_MODE_PARSABLE;
 534                         break;
 535                 case 'q':
 536                         flags |= WP_FL_QUIET;
 537                         break;
 538                 case 't':
 539                         type_pattern = optarg;
 540                         break;
 541                 case 'V':
 542                         printf(UTIL_LINUX_VERSION);
 543                         return EXIT_SUCCESS;
 544                 default:
 545                         usage(stderr);
 546                         break;
 547                 }
 548         }
 549
 550         if (optind == argc)
 551                 usage(stderr);
 552
 553         if ((flags & WP_FL_BACKUP) && !((flags & WP_FL_ALL) || has_offset))
 554                 warnx(_("The --backup option is meaningless in this context"));
 555
 556         if (!(flags & WP_FL_ALL) && !has_offset) {
 557                 /*
 558                  * Print only
 559                  */
 560                 while (optind < argc) {
 561                         wp0 = read_offsets(NULL, argv[optind++]);
 562                         if (wp0)
 563                                 print_all(wp0, mode);
 564                         free_wipe(wp0);
 565                 }
 566         } else {
 567                 /*
 568                  * Erase
 569                  */
 570                 while (optind < argc) {
 571                         wp = clone_offset(wp0);
 572                         wp = do_wipe(wp, argv[optind++], flags);
 573                         free_wipe(wp);
 574                 }
 575         }
 576
 577         return EXIT_SUCCESS;
 578 }