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/*
* wipefs - utility to wipe filesystems from device
*
* Copyright (C) 2009 Red Hat, Inc. All rights reserved.
* Written by Karel Zak <kzak@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <sys/stat.h>
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include <limits.h>
#include <libgen.h>
#include <blkid.h>
#include <libsmartcols.h>
#include "nls.h"
#include "xalloc.h"
#include "strutils.h"
#include "all-io.h"
#include "match.h"
#include "c.h"
#include "closestream.h"
#include "optutils.h"
#include "blkdev.h"
struct wipe_desc {
loff_t offset; /* magic string offset */
size_t len; /* length of magic string */
unsigned char *magic; /* magic string */
char *usage; /* raid, filesystem, ... */
char *type; /* FS type */
char *label; /* FS label */
char *uuid; /* FS uuid */
struct wipe_desc *next;
unsigned int on_disk : 1,
is_parttable : 1;
};
struct wipe_control {
char *devname;
const char *type_pattern; /* -t <pattern> */
const char *lockmode;
struct libscols_table *outtab;
struct wipe_desc *offsets; /* -o <offset> -o <offset> ... */
size_t ndevs; /* number of devices to probe */
char **reread; /* devices to BLKRRPART */
size_t nrereads; /* size of reread */
unsigned int noact : 1,
all : 1,
quiet : 1,
backup : 1,
force : 1,
json : 1,
no_headings : 1,
parsable : 1;
};
/* column IDs */
enum {
COL_UUID = 0,
COL_LABEL,
COL_LEN,
COL_TYPE,
COL_OFFSET,
COL_USAGE,
COL_DEVICE
};
/* column names */
struct colinfo {
const char *name; /* header */
double whint; /* width hint (N < 1 is in percent of termwidth) */
int flags; /* SCOLS_FL_* */
const char *help;
};
/* columns descriptions */
static const struct colinfo infos[] = {
[COL_UUID] = {"UUID", 4, 0, N_("partition/filesystem UUID")},
[COL_LABEL] = {"LABEL", 5, 0, N_("filesystem LABEL")},
[COL_LEN] = {"LENGTH", 6, 0, N_("magic string length")},
[COL_TYPE] = {"TYPE", 4, 0, N_("superblok type")},
[COL_OFFSET] = {"OFFSET", 5, 0, N_("magic string offset")},
[COL_USAGE] = {"USAGE", 5, 0, N_("type description")},
[COL_DEVICE] = {"DEVICE", 5, 0, N_("block device name")}
};
static int columns[ARRAY_SIZE(infos) * 2];
static size_t ncolumns;
static int column_name_to_id(const char *name, size_t namesz)
{
size_t i;
assert(name);
for (i = 0; i < ARRAY_SIZE(infos); i++) {
const char *cn = infos[i].name;
if (!strncasecmp(name, cn, namesz) && !*(cn + namesz))
return i;
}
warnx(_("unknown column: %s"), name);
return -1;
}
static int get_column_id(size_t num)
{
assert(num < ncolumns);
assert(columns[num] < (int)ARRAY_SIZE(infos));
return columns[num];
}
static const struct colinfo *get_column_info(int num)
{
return &infos[get_column_id(num)];
}
static void init_output(struct wipe_control *ctl)
{
struct libscols_table *tb;
size_t i;
scols_init_debug(0);
tb = scols_new_table();
if (!tb)
err(EXIT_FAILURE, _("failed to allocate output table"));
if (ctl->json) {
scols_table_enable_json(tb, 1);
scols_table_set_name(tb, "signatures");
}
scols_table_enable_noheadings(tb, ctl->no_headings);
if (ctl->parsable) {
scols_table_enable_raw(tb, 1);
scols_table_set_column_separator(tb, ",");
}
for (i = 0; i < ncolumns; i++) {
const struct colinfo *col = get_column_info(i);
struct libscols_column *cl;
cl = scols_table_new_column(tb, col->name, col->whint,
col->flags);
if (!cl)
err(EXIT_FAILURE,
_("failed to initialize output column"));
if (ctl->json) {
int id = get_column_id(i);
if (id == COL_LEN)
scols_column_set_json_type(cl, SCOLS_JSON_NUMBER);
}
}
ctl->outtab = tb;
}
static void finalize_output(struct wipe_control *ctl)
{
scols_print_table(ctl->outtab);
scols_unref_table(ctl->outtab);
}
static void fill_table_row(struct wipe_control *ctl, struct wipe_desc *wp)
{
static struct libscols_line *ln;
size_t i;
ln = scols_table_new_line(ctl->outtab, NULL);
if (!ln)
errx(EXIT_FAILURE, _("failed to allocate output line"));
for (i = 0; i < ncolumns; i++) {
char *str = NULL;
switch (get_column_id(i)) {
case COL_UUID:
if (wp->uuid)
str = xstrdup(wp->uuid);
break;
case COL_LABEL:
if (wp->label)
str = xstrdup(wp->label);
break;
case COL_OFFSET:
xasprintf(&str, "0x%jx", (intmax_t)wp->offset);
break;
case COL_LEN:
xasprintf(&str, "%zu", wp->len);
break;
case COL_USAGE:
if (wp->usage)
str = xstrdup(wp->usage);
break;
case COL_TYPE:
if (wp->type)
str = xstrdup(wp->type);
break;
case COL_DEVICE:
if (ctl->devname) {
char *dev = xstrdup(ctl->devname);
str = xstrdup(basename(dev));
free(dev);
}
break;
default:
abort();
}
if (str && scols_line_refer_data(ln, i, str))
errx(EXIT_FAILURE, _("failed to add output data"));
}
}
static void add_to_output(struct wipe_control *ctl, struct wipe_desc *wp)
{
for (/*nothing*/; wp; wp = wp->next)
fill_table_row(ctl, wp);
}
/* Allocates a new wipe_desc and add to the wp0 if not NULL */
static struct wipe_desc *add_offset(struct wipe_desc **wp0, loff_t offset)
{
struct wipe_desc *wp, *last = NULL;
if (wp0) {
/* check if already exists */
for (wp = *wp0; wp; wp = wp->next) {
if (wp->offset == offset)
return wp;
last = wp;
}
}
wp = xcalloc(1, sizeof(struct wipe_desc));
wp->offset = offset;
wp->next = NULL;
if (last)
last->next = wp;
if (wp0 && !*wp0)
*wp0 = wp;
return wp;
}
/* Read data from libblkid and if detected type pass -t and -o filters than:
* - allocates a new wipe_desc
* - add the new wipe_desc to wp0 list (if not NULL)
*
* The function always returns offset and len if libblkid detected something.
*/
static struct wipe_desc *get_desc_for_probe(struct wipe_control *ctl,
struct wipe_desc **wp0,
blkid_probe pr,
loff_t *offset,
size_t *len)
{
const char *off, *type, *mag, *p, *use = NULL;
struct wipe_desc *wp;
int rc, ispt = 0;
*len = 0;
/* superblocks */
if (blkid_probe_lookup_value(pr, "TYPE", &type, NULL) == 0) {
rc = blkid_probe_lookup_value(pr, "SBMAGIC_OFFSET", &off, NULL);
if (!rc)
rc = blkid_probe_lookup_value(pr, "SBMAGIC", &mag, len);
if (rc)
return NULL;
/* partitions */
} else if (blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL) == 0) {
rc = blkid_probe_lookup_value(pr, "PTMAGIC_OFFSET", &off, NULL);
if (!rc)
rc = blkid_probe_lookup_value(pr, "PTMAGIC", &mag, len);
if (rc)
return NULL;
use = N_("partition-table");
ispt = 1;
} else
return NULL;
errno = 0;
*offset = strtoll(off, NULL, 10);
if (errno)
return NULL;
/* Filter out by -t <type> */
if (ctl->type_pattern && !match_fstype(type, ctl->type_pattern))
return NULL;
/* Filter out by -o <offset> */
if (ctl->offsets) {
struct wipe_desc *w = NULL;
for (w = ctl->offsets; w; w = w->next) {
if (w->offset == *offset)
break;
}
if (!w)
return NULL;
w->on_disk = 1; /* mark as "found" */
}
wp = add_offset(wp0, *offset);
if (!wp)
return NULL;
if (use || blkid_probe_lookup_value(pr, "USAGE", &use, NULL) == 0)
wp->usage = xstrdup(use);
wp->type = xstrdup(type);
wp->on_disk = 1;
wp->is_parttable = ispt ? 1 : 0;
wp->magic = xmalloc(*len);
memcpy(wp->magic, mag, *len);
wp->len = *len;
if (blkid_probe_lookup_value(pr, "LABEL", &p, NULL) == 0)
wp->label = xstrdup(p);
if (blkid_probe_lookup_value(pr, "UUID", &p, NULL) == 0)
wp->uuid = xstrdup(p);
return wp;
}
static blkid_probe
new_probe(const char *devname, int mode)
{
blkid_probe pr = NULL;
if (!devname)
return NULL;
if (mode) {
int fd = open(devname, mode | O_NONBLOCK);
if (fd < 0)
goto error;
pr = blkid_new_probe();
if (!pr || blkid_probe_set_device(pr, fd, 0, 0) != 0) {
close(fd);
goto error;
}
} else
pr = blkid_new_probe_from_filename(devname);
if (!pr)
goto error;
blkid_probe_enable_superblocks(pr, 1);
blkid_probe_set_superblocks_flags(pr,
BLKID_SUBLKS_MAGIC | /* return magic string and offset */
BLKID_SUBLKS_TYPE | /* return superblock type */
BLKID_SUBLKS_USAGE | /* return USAGE= */
BLKID_SUBLKS_LABEL | /* return LABEL= */
BLKID_SUBLKS_UUID | /* return UUID= */
BLKID_SUBLKS_BADCSUM); /* accept bad checksums */
blkid_probe_enable_partitions(pr, 1);
blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC |
BLKID_PARTS_FORCE_GPT);
return pr;
error:
blkid_free_probe(pr);
err(EXIT_FAILURE, _("error: %s: probing initialization failed"), devname);
}
static struct wipe_desc *read_offsets(struct wipe_control *ctl)
{
blkid_probe pr = new_probe(ctl->devname, 0);
struct wipe_desc *wp0 = NULL;
if (!pr)
return NULL;
while (blkid_do_probe(pr) == 0) {
size_t len = 0;
loff_t offset = 0;
/* add a new offset to wp0 */
get_desc_for_probe(ctl, &wp0, pr, &offset, &len);
/* hide last detected signature and scan again */
if (len) {
blkid_probe_hide_range(pr, offset, len);
blkid_probe_step_back(pr);
}
}
blkid_free_probe(pr);
return wp0;
}
static void free_wipe(struct wipe_desc *wp)
{
while (wp) {
struct wipe_desc *next = wp->next;
free(wp->usage);
free(wp->type);
free(wp->magic);
free(wp->label);
free(wp->uuid);
free(wp);
wp = next;
}
}
static void do_wipe_real(struct wipe_control *ctl, blkid_probe pr,
struct wipe_desc *w)
{
size_t i;
if (blkid_do_wipe(pr, ctl->noact) != 0)
err(EXIT_FAILURE, _("%s: failed to erase %s magic string at offset 0x%08jx"),
ctl->devname, w->type, (intmax_t)w->offset);
if (ctl->quiet)
return;
printf(P_("%s: %zd byte was erased at offset 0x%08jx (%s): ",
"%s: %zd bytes were erased at offset 0x%08jx (%s): ",
w->len),
ctl->devname, w->len, (intmax_t)w->offset, w->type);
for (i = 0; i < w->len; i++) {
printf("%02x", w->magic[i]);
if (i + 1 < w->len)
fputc(' ', stdout);
}
putchar('\n');
}
static void do_backup(struct wipe_desc *wp, const char *base)
{
char *fname = NULL;
int fd;
xasprintf(&fname, "%s0x%08jx.bak", base, (intmax_t)wp->offset);
fd = open(fname, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
if (fd < 0)
goto err;
if (write_all(fd, wp->magic, wp->len) != 0)
goto err;
close(fd);
free(fname);
return;
err:
err(EXIT_FAILURE, _("%s: failed to create a signature backup"), fname);
}
#ifdef BLKRRPART
static void rereadpt(int fd, const char *devname)
{
struct stat st;
int try = 0;
if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
return;
do {
/*
* Unfortunately, it's pretty common that the first re-read
* without delay is uncuccesful. The reason is probably kernel
* and/or udevd. Let's wait a moment and try more attempts.
*/
xusleep(250000);
errno = 0;
ioctl(fd, BLKRRPART);
if (errno != EBUSY)
break;
} while (try++ < 4);
printf(_("%s: calling ioctl to re-read partition table: %m\n"), devname);
}
#endif
static int do_wipe(struct wipe_control *ctl)
{
int mode = O_RDWR, reread = 0, need_force = 0;
blkid_probe pr;
char *backup = NULL;
struct wipe_desc *w;
if (!ctl->force)
mode |= O_EXCL;
pr = new_probe(ctl->devname, mode);
if (!pr)
return -errno;
if (blkdev_lock(blkid_probe_get_fd(pr),
ctl->devname, ctl->lockmode) != 0) {
blkid_free_probe(pr);
return -1;
}
if (ctl->backup) {
const char *home = getenv ("HOME");
char *tmp = xstrdup(ctl->devname);
if (!home)
errx(EXIT_FAILURE, _("failed to create a signature backup, $HOME undefined"));
xasprintf (&backup, "%s/wipefs-%s-", home, basename(tmp));
free(tmp);
}
while (blkid_do_probe(pr) == 0) {
int wiped = 0;
size_t len = 0;
loff_t offset = 0;
struct wipe_desc *wp;
wp = get_desc_for_probe(ctl, NULL, pr, &offset, &len);
if (!wp)
goto done;
if (!ctl->force
&& wp->is_parttable
&& !blkid_probe_is_wholedisk(pr)) {
warnx(_("%s: ignoring nested \"%s\" partition table "
"on non-whole disk device"), ctl->devname, wp->type);
need_force = 1;
goto done;
}
if (backup)
do_backup(wp, backup);
do_wipe_real(ctl, pr, wp);
if (wp->is_parttable)
reread = 1;
wiped = 1;
done:
if (!wiped && len) {
/* if the offset has not been wiped (probably because
* filtered out by -t or -o) we need to hide it for
* libblkid to try another magic string for the same
* superblock, otherwise libblkid will continue with
* another superblock. Don't forget that the same
* superblock could be detected by more magic strings
* */
blkid_probe_hide_range(pr, offset, len);
blkid_probe_step_back(pr);
}
free_wipe(wp);
}
for (w = ctl->offsets; w; w = w->next) {
if (!w->on_disk && !ctl->quiet)
warnx(_("%s: offset 0x%jx not found"),
ctl->devname, (uintmax_t)w->offset);
}
if (need_force)
warnx(_("Use the --force option to force erase."));
if (fsync(blkid_probe_get_fd(pr)) != 0)
err(EXIT_FAILURE, _("%s: cannot flush modified buffers"),
ctl->devname);
#ifdef BLKRRPART
if (reread && (mode & O_EXCL)) {
if (ctl->ndevs > 1) {
/*
* We're going to probe more device, let's postpone
* re-read PT ioctl until all is erased to avoid
* situation we erase PT on /dev/sda before /dev/sdaN
* devices are processed.
*/
if (!ctl->reread)
ctl->reread = xcalloc(ctl->ndevs, sizeof(char *));
ctl->reread[ctl->nrereads++] = ctl->devname;
} else
rereadpt(blkid_probe_get_fd(pr), ctl->devname);
}
#endif
if (close(blkid_probe_get_fd(pr)) != 0)
err(EXIT_FAILURE, _("%s: close device failed"), ctl->devname);
blkid_free_probe(pr);
free(backup);
return 0;
}
static void __attribute__((__noreturn__))
usage(void)
{
size_t i;
fputs(USAGE_HEADER, stdout);
printf(_(" %s [options] <device>\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, stdout);
puts(_("Wipe signatures from a device."));
fputs(USAGE_OPTIONS, stdout);
puts(_(" -a, --all wipe all magic strings (BE CAREFUL!)"));
puts(_(" -b, --backup create a signature backup in $HOME"));
puts(_(" -f, --force force erasure"));
puts(_(" -i, --noheadings don't print headings"));
puts(_(" -J, --json use JSON output format"));
puts(_(" -n, --no-act do everything except the actual write() call"));
puts(_(" -o, --offset <num> offset to erase, in bytes"));
puts(_(" -O, --output <list> COLUMNS to display (see below)"));
puts(_(" -p, --parsable print out in parsable instead of printable format"));
puts(_(" -q, --quiet suppress output messages"));
puts(_(" -t, --types <list> limit the set of filesystem, RAIDs or partition tables"));
printf(
_(" --lock[=<mode>] use exclusive device lock (%s, %s or %s)\n"), "yes", "no", "nonblock");
printf(USAGE_HELP_OPTIONS(21));
fputs(USAGE_ARGUMENTS, stdout);
printf(USAGE_ARG_SIZE(_("<num>")));
fputs(USAGE_COLUMNS, stdout);
for (i = 0; i < ARRAY_SIZE(infos); i++)
fprintf(stdout, " %8s %s\n", infos[i].name, _(infos[i].help));
printf(USAGE_MAN_TAIL("wipefs(8)"));
exit(EXIT_SUCCESS);
}
int
main(int argc, char **argv)
{
struct wipe_control ctl = { .devname = NULL };
int c;
size_t i;
char *outarg = NULL;
enum {
OPT_LOCK = CHAR_MAX + 1,
};
static const struct option longopts[] = {
{ "all", no_argument, NULL, 'a' },
{ "backup", no_argument, NULL, 'b' },
{ "force", no_argument, NULL, 'f' },
{ "help", no_argument, NULL, 'h' },
{ "lock", optional_argument, NULL, OPT_LOCK },
{ "no-act", no_argument, NULL, 'n' },
{ "offset", required_argument, NULL, 'o' },
{ "parsable", no_argument, NULL, 'p' },
{ "quiet", no_argument, NULL, 'q' },
{ "types", required_argument, NULL, 't' },
{ "version", no_argument, NULL, 'V' },
{ "json", no_argument, NULL, 'J'},
{ "noheadings",no_argument, NULL, 'i'},
{ "output", required_argument, NULL, 'O'},
{ NULL, 0, NULL, 0 }
};
static const ul_excl_t excl[] = { /* rows and cols in ASCII order */
{ 'O','a','o' },
{ 0 }
};
int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
while ((c = getopt_long(argc, argv, "abfhiJnO:o:pqt:V", longopts, NULL)) != -1) {
err_exclusive_options(c, longopts, excl, excl_st);
switch(c) {
case 'a':
ctl.all = 1;
break;
case 'b':
ctl.backup = 1;
break;
case 'f':
ctl.force = 1;
break;
case 'J':
ctl.json = 1;
break;
case 'i':
ctl.no_headings = 1;
break;
case 'O':
outarg = optarg;
break;
case 'n':
ctl.noact = 1;
break;
case 'o':
add_offset(&ctl.offsets, strtosize_or_err(optarg,
_("invalid offset argument")));
break;
case 'p':
ctl.parsable = 1;
ctl.no_headings = 1;
break;
case 'q':
ctl.quiet = 1;
break;
case 't':
ctl.type_pattern = optarg;
break;
case OPT_LOCK:
ctl.lockmode = "1";
if (optarg) {
if (*optarg == '=')
optarg++;
ctl.lockmode = optarg;
}
break;
case 'h':
usage();
case 'V':
print_version(EXIT_SUCCESS);
default:
errtryhelp(EXIT_FAILURE);
}
}
if (optind == argc) {
warnx(_("no device specified"));
errtryhelp(EXIT_FAILURE);
}
if (ctl.backup && !(ctl.all || ctl.offsets))
warnx(_("The --backup option is meaningless in this context"));
if (!ctl.all && !ctl.offsets) {
/*
* Print only
*/
if (ctl.parsable) {
/* keep it backward compatible */
columns[ncolumns++] = COL_OFFSET;
columns[ncolumns++] = COL_UUID;
columns[ncolumns++] = COL_LABEL;
columns[ncolumns++] = COL_TYPE;
} else {
/* default, may be modified by -O <list> */
columns[ncolumns++] = COL_DEVICE;
columns[ncolumns++] = COL_OFFSET;
columns[ncolumns++] = COL_TYPE;
columns[ncolumns++] = COL_UUID;
columns[ncolumns++] = COL_LABEL;
}
if (outarg
&& string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
&ncolumns, column_name_to_id) < 0)
return EXIT_FAILURE;
init_output(&ctl);
while (optind < argc) {
struct wipe_desc *wp;
ctl.devname = argv[optind++];
wp = read_offsets(&ctl);
if (wp)
add_to_output(&ctl, wp);
free_wipe(wp);
}
finalize_output(&ctl);
} else {
/*
* Erase
*/
ctl.ndevs = argc - optind;
while (optind < argc) {
ctl.devname = argv[optind++];
do_wipe(&ctl);
ctl.ndevs--;
}
#ifdef BLKRRPART
/* Re-read partition tables on whole-disk devices. This is
* postponed until all is done to avoid conflicts.
*/
for (i = 0; i < ctl.nrereads; i++) {
char *devname = ctl.reread[i];
int fd = open(devname, O_RDONLY);
if (fd >= 0) {
rereadpt(fd, devname);
close(fd);
}
}
free(ctl.reread);
#endif
}
return EXIT_SUCCESS;
}