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-rw-r--r--sys-utils/umount.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/sys-utils/umount.c b/sys-utils/umount.c
new file mode 100644
index 0000000..f593176
--- /dev/null
+++ b/sys-utils/umount.c
@@ -0,0 +1,650 @@
+/*
+ * 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 rc)
+{
+ char buf[BUFSIZ] = { 0 };
+
+ rc = mnt_context_get_excode(cxt, rc, buf, sizeof(buf));
+
+ /* suppress "not mounted" error message */
+ if (quiet &&
+ rc == MNT_EX_FAIL &&
+ mnt_context_syscall_called(cxt) &&
+ mnt_context_get_syscall_errno(cxt) == EINVAL)
+ return rc;
+
+ /* 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_BACKWARD);
+ 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;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 17:40:06 +0000