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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* This file is part of libmount from util-linux project.
*
* Copyright (C) 2022 Karel Zak <kzak@redhat.com>
*
* libmount is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
*
* Please, see the comment in libmount/src/hooks.c to understand how hooks work.
*/
#include "mountP.h"
#include "fileutils.h"
static int hookset_deinit(struct libmnt_context *cxt, const struct libmnt_hookset *hs)
{
void *data = NULL;
DBG(HOOK, ul_debugobj(hs, "deinit '%s'", hs->name));
/* remove all our hooks and free hook data */
while (mnt_context_remove_hook(cxt, hs, 0, &data) == 0) {
if (data)
free(data);
data = NULL;
}
return 0;
}
static int is_mkdir_required(struct libmnt_context *cxt, const char *tgt, mode_t *mode, int *rc)
{
struct libmnt_optlist *ol;
struct libmnt_opt *opt;
const char *mstr = NULL;
assert(cxt);
assert(cxt->map_userspace);
assert(tgt);
assert(mode);
assert(rc);
*mode = 0;
*rc = 0;
ol = mnt_context_get_optlist(cxt);
if (!ol)
return -ENOMEM;
opt = mnt_optlist_get_named(ol, "X-mount.mkdir", cxt->map_userspace);
if (!opt)
opt = mnt_optlist_get_named(ol, "x-mount.mkdir", cxt->map_userspace);
if (!opt)
return 0;
if (mnt_is_path(tgt))
return 0;
mstr = mnt_opt_get_value(opt);
if (mstr && *mstr) {
char *end = NULL;
if (*mstr == '"')
mstr++;
errno = 0;
*mode = strtol(mstr, &end, 8);
if (errno || !end || !(*end == '"' || *end == '\0')) {
DBG(HOOK, ul_debug("failed to parse mkdir mode '%s'", mstr));
*rc = -MNT_ERR_MOUNTOPT;
return 0;
}
}
if (!*mode)
*mode = S_IRWXU | /* 0755 */
S_IRGRP | S_IXGRP |
S_IROTH | S_IXOTH;
DBG(HOOK, ul_debug("mkdir %s (%o) wanted", tgt, *mode));
return 1;
}
static int hook_prepare_target(
struct libmnt_context *cxt,
const struct libmnt_hookset *hs,
void *data __attribute__((__unused__)))
{
int rc = 0;
mode_t mode = 0;
const char *tgt;
assert(cxt);
tgt = mnt_fs_get_target(cxt->fs);
if (!tgt)
return 0;
if (cxt->action == MNT_ACT_MOUNT
&& is_mkdir_required(cxt, tgt, &mode, &rc)) {
struct libmnt_cache *cache;
/* supported only for root or non-suid mount(8) */
if (!mnt_context_is_restricted(cxt)) {
rc = ul_mkdir_p(tgt, mode);
if (rc)
DBG(HOOK, ul_debugobj(hs, "mkdir %s failed: %m", tgt));
} else
rc = -EPERM;
if (rc == 0) {
cache = mnt_context_get_cache(cxt);
if (cache) {
char *path = mnt_resolve_path(tgt, cache);
if (path && strcmp(path, tgt) != 0)
rc = mnt_fs_set_target(cxt->fs, path);
}
}
}
return rc;
}
const struct libmnt_hookset hookset_mkdir =
{
.name = "__mkdir",
.firststage = MNT_STAGE_PREP_TARGET,
.firstcall = hook_prepare_target,
.deinit = hookset_deinit
};
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