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 #include <libgen.h>
  33
  34 #include <blkid.h>
  35
  36 #include "nls.h"
  37 #include "xalloc.h"
  38 #include "strutils.h"
  39 #include "all-io.h"
  40 #include "match.h"
  41 #include "c.h"
  42 #include "closestream.h"
  43 #include "optutils.h"
  44 #include "blkdev.h"
  45
  46 struct wipe_desc {
  47         loff_t          offset;         /* magic string offset */
  48         size_t          len;            /* length of magic string */
  49         unsigned char   *magic;         /* magic string */
  50
  51         char            *usage;         /* raid, filesystem, ... */
  52         char            *type;          /* FS type */
  53         char            *label;         /* FS label */
  54         char            *uuid;          /* FS uuid */
  55
  56         struct wipe_desc        *next;
  57
  58         unsigned int    zap : 1,
  59                         on_disk : 1,
  60                         is_parttable : 1;
  61
  62 };
  63
  64 enum {
  65         WP_MODE_PRETTY,         /* default */
  66         WP_MODE_PARSABLE
  67 };
  68
  69 enum {
  70         WP_FL_NOACT     = (1 << 1),
  71         WP_FL_ALL       = (1 << 2),
  72         WP_FL_QUIET     = (1 << 3),
  73         WP_FL_BACKUP    = (1 << 4),
  74         WP_FL_FORCE     = (1 << 5)
  75 };
  76
  77 static const char *type_pattern;
  78
  79 static void
  80 print_pretty(struct wipe_desc *wp, int line)
  81 {
  82         if (!line) {
  83                 printf("offset               type\n");
  84                 printf("----------------------------------------------------------------\n");
  85         }
  86
  87         printf("0x%-17jx  %s   [%s]", (intmax_t)wp->offset, wp->type, _(wp->usage));
  88
  89         if (wp->label && *wp->label)
  90                 printf("\n%27s %s", "LABEL:", wp->label);
  91         if (wp->uuid)
  92                 printf("\n%27s %s", "UUID: ", wp->uuid);
  93         puts("\n");
  94 }
  95
  96 static void
  97 print_parsable(struct wipe_desc *wp, int line)
  98 {
  99         char enc[256];
 100
 101         if (!line)
 102                 printf("# offset,uuid,label,type\n");
 103
 104         printf("0x%jx,", (intmax_t)wp->offset);
 105
 106         if (wp->uuid) {
 107                 blkid_encode_string(wp->uuid, enc, sizeof(enc));
 108                 printf("%s,", enc);
 109         } else
 110                 fputc(',', stdout);
 111
 112         if (wp->label) {
 113                 blkid_encode_string(wp->label, enc, sizeof(enc));
 114                 printf("%s,", enc);
 115         } else
 116                 fputc(',', stdout);
 117
 118         blkid_encode_string(wp->type, enc, sizeof(enc));
 119         printf("%s\n", enc);
 120 }
 121
 122 static void
 123 print_all(struct wipe_desc *wp, int mode)
 124 {
 125         int n = 0;
 126
 127         while (wp) {
 128                 switch (mode) {
 129                 case WP_MODE_PRETTY:
 130                         print_pretty(wp, n++);
 131                         break;
 132                 case WP_MODE_PARSABLE:
 133                         print_parsable(wp, n++);
 134                         break;
 135                 default:
 136                         abort();
 137                 }
 138                 wp = wp->next;
 139         }
 140 }
 141
 142 static struct wipe_desc *
 143 add_offset(struct wipe_desc *wp0, loff_t offset, int zap)
 144 {
 145         struct wipe_desc *wp = wp0;
 146
 147         while (wp) {
 148                 if (wp->offset == offset)
 149                         return wp;
 150                 wp = wp->next;
 151         }
 152
 153         wp = xcalloc(1, sizeof(struct wipe_desc));
 154         wp->offset = offset;
 155         wp->next = wp0;
 156         wp->zap = zap ? 1 : 0;
 157         return wp;
 158 }
 159
 160 static struct wipe_desc *
 161 clone_offset(struct wipe_desc *wp0)
 162 {
 163         struct wipe_desc *wp = NULL;
 164
 165         while(wp0) {
 166                 wp = add_offset(wp, wp0->offset, wp0->zap);
 167                 wp0 = wp0->next;
 168         }
 169
 170         return wp;
 171 }
 172
 173 static struct wipe_desc *
 174 get_desc_for_probe(struct wipe_desc *wp, blkid_probe pr)
 175 {
 176         const char *off, *type, *mag, *p, *usage = NULL;
 177         size_t len;
 178         loff_t offset;
 179         int rc, ispt = 0;
 180
 181         /* superblocks */
 182         if (blkid_probe_lookup_value(pr, "TYPE", &type, NULL) == 0) {
 183                 rc = blkid_probe_lookup_value(pr, "SBMAGIC_OFFSET", &off, NULL);
 184                 if (!rc)
 185                         rc = blkid_probe_lookup_value(pr, "SBMAGIC", &mag, &len);
 186                 if (rc)
 187                         return wp;
 188
 189         /* partitions */
 190         } else if (blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL) == 0) {
 191                 rc = blkid_probe_lookup_value(pr, "PTMAGIC_OFFSET", &off, NULL);
 192                 if (!rc)
 193                         rc = blkid_probe_lookup_value(pr, "PTMAGIC", &mag, &len);
 194                 if (rc)
 195                         return wp;
 196                 usage = N_("partition table");
 197                 ispt = 1;
 198         } else
 199                 return wp;
 200
 201         if (type_pattern && !match_fstype(type, type_pattern))
 202                 return wp;
 203
 204         offset = strtoll(off, NULL, 10);
 205
 206         wp = add_offset(wp, offset, 0);
 207         if (!wp)
 208                 return NULL;
 209
 210         if (usage || blkid_probe_lookup_value(pr, "USAGE", &usage, NULL) == 0)
 211                 wp->usage = xstrdup(usage);
 212
 213         wp->type = xstrdup(type);
 214         wp->on_disk = 1;
 215         wp->is_parttable = ispt ? 1 : 0;
 216
 217         wp->magic = xmalloc(len);
 218         memcpy(wp->magic, mag, len);
 219         wp->len = len;
 220
 221         if (blkid_probe_lookup_value(pr, "LABEL", &p, NULL) == 0)
 222                 wp->label = xstrdup(p);
 223
 224         if (blkid_probe_lookup_value(pr, "UUID", &p, NULL) == 0)
 225                 wp->uuid = xstrdup(p);
 226
 227         return wp;
 228 }
 229
 230 static blkid_probe
 231 new_probe(const char *devname, int mode)
 232 {
 233         blkid_probe pr = NULL;
 234
 235         if (!devname)
 236                 return NULL;
 237
 238         if (mode) {
 239                 int fd = open(devname, mode);
 240                 if (fd < 0)
 241                         goto error;
 242
 243                 pr = blkid_new_probe();
 244                 if (!pr || blkid_probe_set_device(pr, fd, 0, 0) != 0) {
 245                         close(fd);
 246                         goto error;
 247                 }
 248         } else
 249                 pr = blkid_new_probe_from_filename(devname);
 250
 251         if (!pr)
 252                 goto error;
 253
 254         blkid_probe_enable_superblocks(pr, 1);
 255         blkid_probe_set_superblocks_flags(pr,
 256                         BLKID_SUBLKS_MAGIC |    /* return magic string and offset */
 257                         BLKID_SUBLKS_TYPE |     /* return superblock type */
 258                         BLKID_SUBLKS_USAGE |    /* return USAGE= */
 259                         BLKID_SUBLKS_LABEL |    /* return LABEL= */
 260                         BLKID_SUBLKS_UUID |     /* return UUID= */
 261                         BLKID_SUBLKS_BADCSUM);  /* accept bad checksums */
 262
 263         blkid_probe_enable_partitions(pr, 1);
 264         blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC |
 265                                              BLKID_PARTS_FORCE_GPT);
 266         return pr;
 267 error:
 268         blkid_free_probe(pr);
 269         err(EXIT_FAILURE, _("error: %s: probing initialization failed"), devname);
 270 }
 271
 272 static struct wipe_desc *
 273 read_offsets(struct wipe_desc *wp, const char *devname)
 274 {
 275         blkid_probe pr = new_probe(devname, 0);
 276
 277         if (!pr)
 278                 return NULL;
 279
 280         while (blkid_do_probe(pr) == 0) {
 281                 wp = get_desc_for_probe(wp, pr);
 282                 if (!wp)
 283                         break;
 284         }
 285
 286         blkid_free_probe(pr);
 287         return wp;
 288 }
 289
 290 static void
 291 free_wipe(struct wipe_desc *wp)
 292 {
 293         while (wp) {
 294                 struct wipe_desc *next = wp->next;
 295
 296                 free(wp->usage);
 297                 free(wp->type);
 298                 free(wp->magic);
 299                 free(wp->label);
 300                 free(wp->uuid);
 301                 free(wp);
 302
 303                 wp = next;
 304         }
 305 }
 306
 307 static void do_wipe_real(blkid_probe pr, const char *devname,
 308                         struct wipe_desc *w, int flags)
 309 {
 310         size_t i;
 311
 312         if (blkid_do_wipe(pr, (flags & WP_FL_NOACT) != 0))
 313                 warn(_("%s: failed to erase %s magic string at offset 0x%08jx"),
 314                      devname, w->type, (intmax_t)w->offset);
 315
 316         if (flags & WP_FL_QUIET)
 317                 return;
 318
 319         printf(P_("%s: %zd byte was erased at offset 0x%08jx (%s): ",
 320                   "%s: %zd bytes were erased at offset 0x%08jx (%s): ",
 321                   w->len),
 322                devname, w->len, (intmax_t)w->offset, w->type);
 323
 324         for (i = 0; i < w->len; i++) {
 325                 printf("%02x", w->magic[i]);
 326                 if (i + 1 < w->len)
 327                         fputc(' ', stdout);
 328         }
 329         putchar('\n');
 330 }
 331
 332 static void do_backup(struct wipe_desc *wp, const char *base)
 333 {
 334         char *fname = NULL;
 335         int fd;
 336
 337         xasprintf(&fname, "%s0x%08jx.bak", base, (intmax_t)wp->offset);
 338
 339         fd = open(fname, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
 340         if (fd < 0)
 341                 goto err;
 342         if (write_all(fd, wp->magic, wp->len) != 0)
 343                 goto err;
 344         close(fd);
 345         free(fname);
 346         return;
 347 err:
 348         err(EXIT_FAILURE, _("%s: failed to create a signature backup"), fname);
 349 }
 350
 351 #ifdef BLKRRPART
 352 static void rereadpt(int fd, const char *devname)
 353 {
 354         struct stat st;
 355
 356         if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
 357                 return;
 358
 359         errno = 0;
 360         ioctl(fd, BLKRRPART);
 361         printf(_("%s: calling ioctl to re-read partition table: %m\n"), devname);
 362 }
 363 #endif
 364
 365 static struct wipe_desc *
 366 do_wipe(struct wipe_desc *wp, const char *devname, int flags)
 367 {
 368         int mode = O_RDWR, reread = 0, need_force = 0;
 369         blkid_probe pr;
 370         struct wipe_desc *w, *wp0;
 371         int zap = (flags & WP_FL_ALL) ? 1 : wp->zap;
 372         char *backup = NULL;
 373
 374         if (!(flags & WP_FL_FORCE))
 375                 mode |= O_EXCL;
 376         pr = new_probe(devname, mode);
 377         if (!pr)
 378                 return NULL;
 379
 380         if (zap && (flags & WP_FL_BACKUP)) {
 381                 const char *home = getenv ("HOME");
 382                 char *tmp = xstrdup(devname);
 383
 384                 if (!home)
 385                         errx(EXIT_FAILURE, _("failed to create a signature backup, $HOME undefined"));
 386                 xasprintf (&backup, "%s/wipefs-%s-", home, basename(tmp));
 387                 free(tmp);
 388         }
 389
 390         wp0 = clone_offset(wp);
 391
 392         while (blkid_do_probe(pr) == 0) {
 393                 wp = get_desc_for_probe(wp, pr);
 394                 if (!wp)
 395                         break;
 396
 397                 /* Check if offset is in provided list */
 398                 w = wp0;
 399                 while(w && w->offset != wp->offset)
 400                         w = w->next;
 401                 if (wp0 && !w)
 402                         continue;
 403
 404                 /* Mark done if found in provided list */
 405                 if (w)
 406                         w->on_disk = wp->on_disk;
 407
 408                 if (!wp->on_disk)
 409                         continue;
 410
 411                 if (!(flags & WP_FL_FORCE)
 412                     && wp->is_parttable
 413                     && !blkid_probe_is_wholedisk(pr)) {
 414                         warnx(_("%s: ignoring nested \"%s\" partition table "
 415                                 "on non-whole disk device"), devname, wp->type);
 416                         need_force = 1;
 417                         continue;
 418                 }
 419
 420                 if (zap) {
 421                         if (backup)
 422                                 do_backup(wp, backup);
 423                         do_wipe_real(pr, devname, wp, flags);
 424                         if (wp->is_parttable)
 425                                 reread = 1;
 426                 }
 427         }
 428
 429         for (w = wp0; w != NULL; w = w->next) {
 430                 if (!w->on_disk && !(flags & WP_FL_QUIET))
 431                         warnx(_("%s: offset 0x%jx not found"), devname, (uintmax_t)w->offset);
 432         }
 433
 434         if (need_force)
 435                 warnx(_("Use the --force option to force erase."));
 436
 437         fsync(blkid_probe_get_fd(pr));
 438
 439 #ifdef BLKRRPART
 440         if (reread && (mode & O_EXCL))
 441                 rereadpt(blkid_probe_get_fd(pr), devname);
 442 #endif
 443
 444         close(blkid_probe_get_fd(pr));
 445         blkid_free_probe(pr);
 446         free_wipe(wp0);
 447         free(backup);
 448
 449         return wp;
 450 }
 451
 452
 453 static void __attribute__((__noreturn__))
 454 usage(FILE *out)
 455 {
 456         fputs(USAGE_HEADER, out);
 457         fprintf(out,
 458               _(" %s [options] <device>\n"), program_invocation_short_name);
 459
 460         fputs(USAGE_SEPARATOR, out);
 461         fputs(_("Wipe signatures from a device.\n"), out);
 462
 463         fputs(USAGE_OPTIONS, out);
 464         fputs(_(" -a, --all           wipe all magic strings (BE CAREFUL!)\n"
 465                 " -b, --backup        create a signature backup in $HOME\n"
 466                 " -f, --force         force erasure\n"
 467                 " -h, --help          show this help text\n"
 468                 " -n, --no-act        do everything except the actual write() call\n"
 469                 " -o, --offset <num>  offset to erase, in bytes\n"
 470                 " -p, --parsable      print out in parsable instead of printable format\n"
 471                 " -q, --quiet         suppress output messages\n"
 472                 " -t, --types <list>  limit the set of filesystem, RAIDs or partition tables\n"
 473                 " -V, --version       output version information and exit\n"), out);
 474
 475         fprintf(out, USAGE_MAN_TAIL("wipefs(8)"));
 476
 477         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 478 }
 479
 480
 481 int
 482 main(int argc, char **argv)
 483 {
 484         struct wipe_desc *wp0 = NULL, *wp;
 485         int c, has_offset = 0, flags = 0;
 486         int mode = WP_MODE_PRETTY;
 487
 488         static const struct option longopts[] = {
 489             { "all",       0, 0, 'a' },
 490             { "backup",    0, 0, 'b' },
 491             { "force",     0, 0, 'f' },
 492             { "help",      0, 0, 'h' },
 493             { "no-act",    0, 0, 'n' },
 494             { "offset",    1, 0, 'o' },
 495             { "parsable",  0, 0, 'p' },
 496             { "quiet",     0, 0, 'q' },
 497             { "types",     1, 0, 't' },
 498             { "version",   0, 0, 'V' },
 499             { NULL,        0, 0, 0 }
 500         };
 501
 502         static const ul_excl_t excl[] = {       /* rows and cols in in ASCII order */
 503                 { 'a','o' },
 504                 { 0 }
 505         };
 506         int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
 507
 508         setlocale(LC_ALL, "");
 509         bindtextdomain(PACKAGE, LOCALEDIR);
 510         textdomain(PACKAGE);
 511         atexit(close_stdout);
 512
 513         while ((c = getopt_long(argc, argv, "abfhno:pqt:V", longopts, NULL)) != -1) {
 514
 515                 err_exclusive_options(c, longopts, excl, excl_st);
 516
 517                 switch(c) {
 518                 case 'a':
 519                         flags |= WP_FL_ALL;
 520                         break;
 521                 case 'b':
 522                         flags |= WP_FL_BACKUP;
 523                         break;
 524                 case 'f':
 525                         flags |= WP_FL_FORCE;
 526                         break;
 527                 case 'h':
 528                         usage(stdout);
 529                         break;
 530                 case 'n':
 531                         flags |= WP_FL_NOACT;
 532                         break;
 533                 case 'o':
 534                         wp0 = add_offset(wp0, strtosize_or_err(optarg,
 535                                          _("invalid offset argument")), 1);
 536                         has_offset++;
 537                         break;
 538                 case 'p':
 539                         mode = WP_MODE_PARSABLE;
 540                         break;
 541                 case 'q':
 542                         flags |= WP_FL_QUIET;
 543                         break;
 544                 case 't':
 545                         type_pattern = optarg;
 546                         break;
 547                 case 'V':
 548                         printf(UTIL_LINUX_VERSION);
 549                         return EXIT_SUCCESS;
 550                 default:
 551                         errtryhelp(EXIT_FAILURE);
 552                 }
 553         }
 554
 555         if (optind == argc)
 556                 usage(stderr);
 557
 558         if ((flags & WP_FL_BACKUP) && !((flags & WP_FL_ALL) || has_offset))
 559                 warnx(_("The --backup option is meaningless in this context"));
 560
 561         if (!(flags & WP_FL_ALL) && !has_offset) {
 562                 /*
 563                  * Print only
 564                  */
 565                 while (optind < argc) {
 566                         wp0 = read_offsets(NULL, argv[optind++]);
 567                         if (wp0)
 568                                 print_all(wp0, mode);
 569                         free_wipe(wp0);
 570                 }
 571         } else {
 572                 /*
 573                  * Erase
 574                  */
 575                 while (optind < argc) {
 576                         wp = clone_offset(wp0);
 577                         wp = do_wipe(wp, argv[optind++], flags);
 578                         free_wipe(wp);
 579                 }
 580         }
 581
 582         return EXIT_SUCCESS;
 583 }