zfs-builds-mm/zfs-2.0.0/module/os/freebsd/spl/spl_zone.c
2020-12-02 17:25:31 +01:00

260 lines
6.3 KiB
C

/*
* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/jail.h>
#include <sys/osd.h>
#include <sys/priv.h>
#include <sys/zone.h>
#include <sys/policy.h>
static MALLOC_DEFINE(M_ZONES, "zones_data", "Zones data");
/*
* Structure to record list of ZFS datasets exported to a zone.
*/
typedef struct zone_dataset {
LIST_ENTRY(zone_dataset) zd_next;
char zd_dataset[0];
} zone_dataset_t;
LIST_HEAD(zone_dataset_head, zone_dataset);
static int zone_slot;
int
zone_dataset_attach(struct ucred *cred, const char *dataset, int jailid)
{
struct zone_dataset_head *head;
zone_dataset_t *zd, *zd2;
struct prison *pr;
int dofree, error;
if ((error = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 0)
return (error);
/* Allocate memory before we grab prison's mutex. */
zd = malloc(sizeof (*zd) + strlen(dataset) + 1, M_ZONES, M_WAITOK);
sx_slock(&allprison_lock);
pr = prison_find(jailid); /* Locks &pr->pr_mtx. */
sx_sunlock(&allprison_lock);
if (pr == NULL) {
free(zd, M_ZONES);
return (ENOENT);
}
head = osd_jail_get(pr, zone_slot);
if (head != NULL) {
dofree = 0;
LIST_FOREACH(zd2, head, zd_next) {
if (strcmp(dataset, zd2->zd_dataset) == 0) {
free(zd, M_ZONES);
error = EEXIST;
goto end;
}
}
} else {
dofree = 1;
prison_hold_locked(pr);
mtx_unlock(&pr->pr_mtx);
head = malloc(sizeof (*head), M_ZONES, M_WAITOK);
LIST_INIT(head);
mtx_lock(&pr->pr_mtx);
error = osd_jail_set(pr, zone_slot, head);
KASSERT(error == 0, ("osd_jail_set() failed (error=%d)",
error));
}
strcpy(zd->zd_dataset, dataset);
LIST_INSERT_HEAD(head, zd, zd_next);
end:
if (dofree)
prison_free_locked(pr);
else
mtx_unlock(&pr->pr_mtx);
return (error);
}
int
zone_dataset_detach(struct ucred *cred, const char *dataset, int jailid)
{
struct zone_dataset_head *head;
zone_dataset_t *zd;
struct prison *pr;
int error;
if ((error = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 0)
return (error);
sx_slock(&allprison_lock);
pr = prison_find(jailid);
sx_sunlock(&allprison_lock);
if (pr == NULL)
return (ENOENT);
head = osd_jail_get(pr, zone_slot);
if (head == NULL) {
error = ENOENT;
goto end;
}
LIST_FOREACH(zd, head, zd_next) {
if (strcmp(dataset, zd->zd_dataset) == 0)
break;
}
if (zd == NULL)
error = ENOENT;
else {
LIST_REMOVE(zd, zd_next);
free(zd, M_ZONES);
if (LIST_EMPTY(head))
osd_jail_del(pr, zone_slot);
error = 0;
}
end:
mtx_unlock(&pr->pr_mtx);
return (error);
}
/*
* Returns true if the named dataset is visible in the current zone.
* The 'write' parameter is set to 1 if the dataset is also writable.
*/
int
zone_dataset_visible(const char *dataset, int *write)
{
struct zone_dataset_head *head;
zone_dataset_t *zd;
struct prison *pr;
size_t len;
int ret = 0;
if (dataset[0] == '\0')
return (0);
if (INGLOBALZONE(curproc)) {
if (write != NULL)
*write = 1;
return (1);
}
pr = curthread->td_ucred->cr_prison;
mtx_lock(&pr->pr_mtx);
head = osd_jail_get(pr, zone_slot);
if (head == NULL)
goto end;
/*
* Walk the list once, looking for datasets which match exactly, or
* specify a dataset underneath an exported dataset. If found, return
* true and note that it is writable.
*/
LIST_FOREACH(zd, head, zd_next) {
len = strlen(zd->zd_dataset);
if (strlen(dataset) >= len &&
bcmp(dataset, zd->zd_dataset, len) == 0 &&
(dataset[len] == '\0' || dataset[len] == '/' ||
dataset[len] == '@')) {
if (write)
*write = 1;
ret = 1;
goto end;
}
}
/*
* Walk the list a second time, searching for datasets which are parents
* of exported datasets. These should be visible, but read-only.
*
* Note that we also have to support forms such as 'pool/dataset/', with
* a trailing slash.
*/
LIST_FOREACH(zd, head, zd_next) {
len = strlen(dataset);
if (dataset[len - 1] == '/')
len--; /* Ignore trailing slash */
if (len < strlen(zd->zd_dataset) &&
bcmp(dataset, zd->zd_dataset, len) == 0 &&
zd->zd_dataset[len] == '/') {
if (write)
*write = 0;
ret = 1;
goto end;
}
}
end:
mtx_unlock(&pr->pr_mtx);
return (ret);
}
static void
zone_destroy(void *arg)
{
struct zone_dataset_head *head;
zone_dataset_t *zd;
head = arg;
while ((zd = LIST_FIRST(head)) != NULL) {
LIST_REMOVE(zd, zd_next);
free(zd, M_ZONES);
}
free(head, M_ZONES);
}
uint32_t
zone_get_hostid(void *ptr)
{
KASSERT(ptr == NULL, ("only NULL pointer supported in %s", __func__));
return ((uint32_t)curthread->td_ucred->cr_prison->pr_hostid);
}
static void
zone_sysinit(void *arg __unused)
{
zone_slot = osd_jail_register(zone_destroy, NULL);
}
static void
zone_sysuninit(void *arg __unused)
{
osd_jail_deregister(zone_slot);
}
SYSINIT(zone_sysinit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysinit, NULL);
SYSUNINIT(zone_sysuninit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysuninit, NULL);