diff options
Diffstat (limited to 'misc-utils/wipefs.c')
-rw-r--r-- | misc-utils/wipefs.c | 837 |
1 files changed, 837 insertions, 0 deletions
diff --git a/misc-utils/wipefs.c b/misc-utils/wipefs.c new file mode 100644 index 0000000..6be470b --- /dev/null +++ b/misc-utils/wipefs.c @@ -0,0 +1,837 @@ +/* + * 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; +} |