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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
commit | cfe5e3905201349e9cf3f95d52ff4bd100bde37d (patch) | |
tree | d0baf160cbee3195249d095f85e52d20c21acf02 /sys-utils/umount.c | |
parent | Initial commit. (diff) | |
download | util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.tar.xz util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.zip |
Adding upstream version 2.39.3.upstream/2.39.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sys-utils/umount.c')
-rw-r--r-- | sys-utils/umount.c | 659 |
1 files changed, 659 insertions, 0 deletions
diff --git a/sys-utils/umount.c b/sys-utils/umount.c new file mode 100644 index 0000000..3a740ae --- /dev/null +++ b/sys-utils/umount.c @@ -0,0 +1,659 @@ +/* + * umount(8) -- mount a filesystem + * + * Copyright (C) 2011 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 <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <getopt.h> +#include <unistd.h> +#include <sys/types.h> + +#include <libmount.h> + +#include "nls.h" +#include "c.h" +#include "env.h" +#include "closestream.h" +#include "pathnames.h" +#include "canonicalize.h" + +#define XALLOC_EXIT_CODE MNT_EX_SYSERR +#include "xalloc.h" + +#define OPTUTILS_EXIT_CODE MNT_EX_USAGE +#include "optutils.h" + +static int quiet; +static struct ul_env_list *envs_removed; + +static int table_parser_errcb(struct libmnt_table *tb __attribute__((__unused__)), + const char *filename, int line) +{ + if (filename) + warnx(_("%s: parse error at line %d -- ignored"), filename, line); + return 1; +} + + +static void __attribute__((__noreturn__)) umount_print_version(void) +{ + const char *ver = NULL; + const char **features = NULL, **p; + + mnt_get_library_version(&ver); + mnt_get_library_features(&features); + + printf(_("%s from %s (libmount %s"), + program_invocation_short_name, + PACKAGE_STRING, + ver); + p = features; + while (p && *p) { + fputs(p == features ? ": " : ", ", stdout); + fputs(*p++, stdout); + } + fputs(")\n", stdout); + exit(MNT_EX_SUCCESS); +} +static void __attribute__((__noreturn__)) usage(void) +{ + FILE *out = stdout; + fputs(USAGE_HEADER, out); + fprintf(out, _( + " %1$s [-hV]\n" + " %1$s -a [options]\n" + " %1$s [options] <source> | <directory>\n"), + program_invocation_short_name); + + fputs(USAGE_SEPARATOR, out); + fputs(_("Unmount filesystems.\n"), out); + + fputs(USAGE_OPTIONS, out); + fputs(_(" -a, --all unmount all filesystems\n"), out); + fputs(_(" -A, --all-targets unmount all mountpoints for the given device in the\n" + " current namespace\n"), out); + fputs(_(" -c, --no-canonicalize don't canonicalize paths\n"), out); + fputs(_(" -d, --detach-loop if mounted loop device, also free this loop device\n"), out); + fputs(_(" --fake dry run; skip the umount(2) syscall\n"), out); + fputs(_(" -f, --force force unmount (in case of an unreachable NFS system)\n"), out); + fputs(_(" -i, --internal-only don't call the umount.<type> helpers\n"), out); + fputs(_(" -n, --no-mtab don't write to /etc/mtab\n"), out); + fputs(_(" -l, --lazy detach the filesystem now, clean up things later\n"), out); + fputs(_(" -O, --test-opts <list> limit the set of filesystems (use with -a)\n"), out); + fputs(_(" -R, --recursive recursively unmount a target with all its children\n"), out); + fputs(_(" -r, --read-only in case unmounting fails, try to remount read-only\n"), out); + fputs(_(" -t, --types <list> limit the set of filesystem types\n"), out); + fputs(_(" -v, --verbose say what is being done\n"), out); + fputs(_(" -q, --quiet suppress 'not mounted' error messages\n"), out); + fputs(_(" -N, --namespace <ns> perform umount in another namespace\n"), out); + + fputs(USAGE_SEPARATOR, out); + printf(USAGE_HELP_OPTIONS(25)); + printf(USAGE_MAN_TAIL("umount(8)")); + + exit(MNT_EX_SUCCESS); +} + +static void suid_drop(struct libmnt_context *cxt) +{ + const uid_t ruid = getuid(); + const uid_t euid = geteuid(); + + if (ruid != 0 && euid == 0 && drop_permissions() != 0) + err(MNT_EX_FAIL, _("drop permissions failed")); + + /* be paranoid and check it, setuid(0) has to fail */ + if (ruid != 0 && setuid(0) == 0) + errx(MNT_EX_FAIL, _("drop permissions failed.")); + + mnt_context_force_unrestricted(cxt); + + /* restore "bad" environment variables */ + if (envs_removed) { + env_list_setenv(envs_removed); + env_list_free(envs_removed); + envs_removed = NULL; + } +} + +static void success_message(struct libmnt_context *cxt) +{ + const char *tgt, *src; + + if (mnt_context_helper_executed(cxt) + || mnt_context_get_status(cxt) != 1) + return; + + tgt = mnt_context_get_target(cxt); + if (!tgt) + return; + + src = mnt_context_get_source(cxt); + if (src) + warnx(_("%s (%s) unmounted"), tgt, src); + else + warnx(_("%s unmounted"), tgt); +} + +static int mk_exit_code(struct libmnt_context *cxt, int api_rc) +{ + char buf[BUFSIZ] = { 0 }; + int rc; + + rc = mnt_context_get_excode(cxt, api_rc, buf, sizeof(buf)); + + /* suppress "not mounted" error message */ + if (quiet) { + switch (rc) { + case MNT_EX_USAGE: + if (api_rc == -EPERM) /* non-root user */ + return rc; + break; + case MNT_EX_FAIL: + if (mnt_context_syscall_called(cxt) && + mnt_context_get_syscall_errno(cxt) == EINVAL) + return rc; + break; + } + } + + /* print errors/warnings */ + if (*buf) { + const char *spec = mnt_context_get_target(cxt); + if (!spec) + spec = mnt_context_get_source(cxt); + if (!spec) + spec = "???"; + warnx("%s: %s.", spec, buf); + } + return rc; +} + +static int umount_all(struct libmnt_context *cxt) +{ + struct libmnt_iter *itr; + struct libmnt_fs *fs; + int mntrc, ignored, rc = 0; + + itr = mnt_new_iter(MNT_ITER_BACKWARD); + if (!itr) { + warn(_("failed to initialize libmount iterator")); + return MNT_EX_SYSERR; + } + + while (mnt_context_next_umount(cxt, itr, &fs, &mntrc, &ignored) == 0) { + + const char *tgt = mnt_fs_get_target(fs); + + if (ignored) { + if (mnt_context_is_verbose(cxt)) + printf(_("%-25s: ignored\n"), tgt); + } else { + int xrc = mk_exit_code(cxt, mntrc); + + if (xrc == MNT_EX_SUCCESS + && mnt_context_is_verbose(cxt)) + printf("%-25s: successfully unmounted\n", tgt); + rc |= xrc; + } + } + + mnt_free_iter(itr); + return rc; +} + +static int umount_one(struct libmnt_context *cxt, const char *spec) +{ + int rc; + + if (!spec) + return MNT_EX_SOFTWARE; + + if (mnt_context_set_target(cxt, spec)) + err(MNT_EX_SYSERR, _("failed to set umount target")); + + rc = mnt_context_umount(cxt); + + if (rc == -EPERM + && mnt_context_is_restricted(cxt) + && mnt_context_tab_applied(cxt) + && !mnt_context_syscall_called(cxt)) { + /* Mountpoint exists, but failed something else in libmount, + * drop perms and try it again */ + suid_drop(cxt); + rc = mnt_context_umount(cxt); + } + + rc = mk_exit_code(cxt, rc); + + if (rc == MNT_EX_SUCCESS && mnt_context_is_verbose(cxt)) + success_message(cxt); + + mnt_reset_context(cxt); + return rc; +} + +static struct libmnt_table *new_mountinfo(struct libmnt_context *cxt) +{ + struct libmnt_table *tb; + struct libmnt_ns *ns_old = mnt_context_switch_target_ns(cxt); + + if (!ns_old) + err(MNT_EX_SYSERR, _("failed to switch namespace")); + + tb = mnt_new_table(); + if (!tb) + err(MNT_EX_SYSERR, _("libmount table allocation failed")); + + mnt_table_set_parser_errcb(tb, table_parser_errcb); + mnt_table_set_cache(tb, mnt_context_get_cache(cxt)); + + if (mnt_table_parse_file(tb, _PATH_PROC_MOUNTINFO)) { + warn(_("failed to parse %s"), _PATH_PROC_MOUNTINFO); + mnt_unref_table(tb); + tb = NULL; + } + + if (!mnt_context_switch_ns(cxt, ns_old)) + err(MNT_EX_SYSERR, _("failed to switch namespace")); + + return tb; +} + +/* + * like umount_one() but does not return error is @spec not mounted + */ +static int umount_one_if_mounted(struct libmnt_context *cxt, const char *spec) +{ + int rc; + struct libmnt_fs *fs; + + rc = mnt_context_find_umount_fs(cxt, spec, &fs); + if (rc == 1) { + rc = MNT_EX_SUCCESS; /* already unmounted */ + mnt_reset_context(cxt); + } else if (rc < 0) { + rc = mk_exit_code(cxt, rc); /* error */ + mnt_reset_context(cxt); + } else + rc = umount_one(cxt, mnt_fs_get_target(fs)); + + return rc; +} + +static int umount_do_recurse(struct libmnt_context *cxt, + struct libmnt_table *tb, struct libmnt_fs *fs) +{ + struct libmnt_fs *child, *over = NULL; + struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_BACKWARD); + int rc; + + if (!itr) + err(MNT_EX_SYSERR, _("libmount iterator allocation failed")); + + /* first try overmount */ + if (mnt_table_over_fs(tb, fs, &over) == 0 && over) { + rc = umount_do_recurse(cxt, tb, over); + if (rc != MNT_EX_SUCCESS) + goto done; + } + + /* umount all children */ + for (;;) { + rc = mnt_table_next_child_fs(tb, itr, fs, &child); + if (rc < 0) { + warnx(_("failed to get child fs of %s"), + mnt_fs_get_target(fs)); + rc = MNT_EX_SOFTWARE; + goto done; + } else if (rc == 1) + break; /* no more children */ + + if (over && child == over) + continue; + + rc = umount_do_recurse(cxt, tb, child); + if (rc != MNT_EX_SUCCESS) + goto done; + } + + rc = umount_one_if_mounted(cxt, mnt_fs_get_target(fs)); +done: + mnt_free_iter(itr); + return rc; +} + +static int umount_recursive(struct libmnt_context *cxt, const char *spec) +{ + struct libmnt_table *tb; + struct libmnt_fs *fs; + int rc; + + tb = new_mountinfo(cxt); + if (!tb) + return MNT_EX_SOFTWARE; + + /* it's always real mountpoint, don't assume that the target maybe a device */ + mnt_context_disable_swapmatch(cxt, 1); + + fs = mnt_table_find_target(tb, spec, MNT_ITER_FORWARD); + if (fs) + rc = umount_do_recurse(cxt, tb, fs); + else { + rc = MNT_EX_USAGE; + if (!quiet) + warnx(access(spec, F_OK) == 0 ? + _("%s: not mounted") : + _("%s: not found"), spec); + } + + mnt_unref_table(tb); + return rc; +} + +static int umount_alltargets(struct libmnt_context *cxt, const char *spec, int rec) +{ + struct libmnt_fs *fs; + struct libmnt_table *tb; + struct libmnt_iter *itr = NULL; + dev_t devno = 0; + int rc; + + /* Convert @spec to device name, Use the same logic like regular + * "umount <spec>". + */ + rc = mnt_context_find_umount_fs(cxt, spec, &fs); + if (rc == 1) { + rc = MNT_EX_USAGE; + if (!quiet) + warnx(access(spec, F_OK) == 0 ? + _("%s: not mounted") : + _("%s: not found"), spec); + return rc; + } + if (rc < 0) + return mk_exit_code(cxt, rc); /* error */ + + if (!mnt_fs_get_srcpath(fs) || !mnt_fs_get_devno(fs)) + errx(MNT_EX_USAGE, _("%s: failed to determine source " + "(--all-targets is unsupported on systems with " + "regular mtab file)."), spec); + + itr = mnt_new_iter(MNT_ITER_BACKWARD); + if (!itr) + err(MNT_EX_SYSERR, _("libmount iterator allocation failed")); + + /* get on @cxt independent mountinfo */ + tb = new_mountinfo(cxt); + if (!tb) { + rc = MNT_EX_SOFTWARE; + goto done; + } + + /* Note that @fs is from mount context and the context will be reset + * after each umount() call */ + devno = mnt_fs_get_devno(fs); + fs = NULL; + + mnt_reset_context(cxt); + + while (mnt_table_next_fs(tb, itr, &fs) == 0) { + if (mnt_fs_get_devno(fs) != devno) + continue; + mnt_context_disable_swapmatch(cxt, 1); + if (rec) + rc = umount_do_recurse(cxt, tb, fs); + else + rc = umount_one_if_mounted(cxt, mnt_fs_get_target(fs)); + + if (rc != MNT_EX_SUCCESS) + break; + } + +done: + mnt_free_iter(itr); + mnt_unref_table(tb); + + return rc; +} + +/* + * Check path -- non-root user should not be able to resolve path which is + * unreadable for them. + */ +static char *sanitize_path(const char *path) +{ + char *p; + + if (!path) + return NULL; + + p = canonicalize_path_restricted(path); + if (!p) + err(MNT_EX_USAGE, "%s", path); + + return p; +} + +static pid_t parse_pid(const char *str) +{ + char *end; + pid_t ret; + + errno = 0; + ret = strtoul(str, &end, 10); + + if (ret < 0 || errno || end == str || (end && *end)) + return 0; + return ret; +} + +int main(int argc, char **argv) +{ + int c, rc = 0, all = 0, recursive = 0, alltargets = 0; + struct libmnt_context *cxt; + char *types = NULL; + + enum { + UMOUNT_OPT_FAKE = CHAR_MAX + 1, + }; + + static const struct option longopts[] = { + { "all", no_argument, NULL, 'a' }, + { "all-targets", no_argument, NULL, 'A' }, + { "detach-loop", no_argument, NULL, 'd' }, + { "fake", no_argument, NULL, UMOUNT_OPT_FAKE }, + { "force", no_argument, NULL, 'f' }, + { "help", no_argument, NULL, 'h' }, + { "internal-only", no_argument, NULL, 'i' }, + { "lazy", no_argument, NULL, 'l' }, + { "no-canonicalize", no_argument, NULL, 'c' }, + { "no-mtab", no_argument, NULL, 'n' }, + { "quiet", no_argument, NULL, 'q' }, + { "read-only", no_argument, NULL, 'r' }, + { "recursive", no_argument, NULL, 'R' }, + { "test-opts", required_argument, NULL, 'O' }, + { "types", required_argument, NULL, 't' }, + { "verbose", no_argument, NULL, 'v' }, + { "version", no_argument, NULL, 'V' }, + { "namespace", required_argument, NULL, 'N' }, + { NULL, 0, NULL, 0 } + }; + + static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ + { 'A','a' }, /* all-targets,all */ + { 'R','a' }, /* recursive,all */ + { 'O','R','t'}, /* options,recursive,types */ + { 'R','r' }, /* recursive,read-only */ + { 0 } + }; + int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; + + __sanitize_env(&envs_removed); + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + close_stdout_atexit(); + + mnt_init_debug(0); + cxt = mnt_new_context(); + if (!cxt) + err(MNT_EX_SYSERR, _("libmount context allocation failed")); + + mnt_context_set_tables_errcb(cxt, table_parser_errcb); + + while ((c = getopt_long(argc, argv, "aAcdfhilnqRrO:t:vVN:", + longopts, NULL)) != -1) { + + + /* only few options are allowed for non-root users */ + if (mnt_context_is_restricted(cxt) && !strchr("hdilqVv", c)) { + + /* Silently ignore options without direct impact to the + * umount operation, but with security sensitive + * side-effects */ + if (strchr("c", c)) + continue; /* ignore */ + + /* drop permissions, continue as regular user */ + suid_drop(cxt); + } + + err_exclusive_options(c, longopts, excl, excl_st); + + switch(c) { + case 'a': + all = 1; + break; + case 'A': + alltargets = 1; + break; + case 'c': + mnt_context_disable_canonicalize(cxt, TRUE); + break; + case 'd': + mnt_context_enable_loopdel(cxt, TRUE); + break; + case UMOUNT_OPT_FAKE: + mnt_context_enable_fake(cxt, TRUE); + break; + case 'f': + mnt_context_enable_force(cxt, TRUE); + break; + case 'i': + mnt_context_disable_helpers(cxt, TRUE); + break; + case 'l': + mnt_context_enable_lazy(cxt, TRUE); + break; + case 'n': + mnt_context_disable_mtab(cxt, TRUE); + break; + case 'q': + quiet = 1; + break; + case 'r': + mnt_context_enable_rdonly_umount(cxt, TRUE); + break; + case 'R': + recursive = TRUE; + break; + case 'O': + if (mnt_context_set_options_pattern(cxt, optarg)) + err(MNT_EX_SYSERR, _("failed to set options pattern")); + break; + case 't': + types = optarg; + break; + case 'v': + mnt_context_enable_verbose(cxt, TRUE); + break; + case 'N': + { + char path[PATH_MAX]; + pid_t pid = parse_pid(optarg); + + if (pid) + snprintf(path, sizeof(path), "/proc/%i/ns/mnt", pid); + + if (mnt_context_set_target_ns(cxt, pid ? path : optarg)) + err(MNT_EX_SYSERR, _("failed to set target namespace to %s"), pid ? path : optarg); + break; + } + + case 'h': + mnt_free_context(cxt); + usage(); + case 'V': + mnt_free_context(cxt); + umount_print_version(); + default: + errtryhelp(MNT_EX_USAGE); + } + } + + argc -= optind; + argv += optind; + + if (all) { + if (argc) { + warnx(_("unexpected number of arguments")); + errtryhelp(MNT_EX_USAGE); + } + if (!types) + types = "noproc,nodevfs,nodevpts,nosysfs,norpc_pipefs,nonfsd,noselinuxfs"; + + mnt_context_set_fstype_pattern(cxt, types); + rc = umount_all(cxt); + + } else if (argc < 1) { + warnx(_("bad usage")); + errtryhelp(MNT_EX_USAGE); + + } else if (alltargets) { + while (argc--) + rc += umount_alltargets(cxt, *argv++, recursive); + } else if (recursive) { + while (argc--) + rc += umount_recursive(cxt, *argv++); + } else { + while (argc--) { + char *path = *argv; + + if (mnt_context_is_restricted(cxt) + && !mnt_tag_is_valid(path)) + path = sanitize_path(path); + + rc += umount_one(cxt, path); + + if (path != *argv) + free(path); + argv++; + } + } + + mnt_free_context(cxt); + env_list_free(envs_removed); + + return (rc < 256) ? rc : 255; +} + |