freebsd-dev/sys/cddl/compat/opensolaris/kern/opensolaris_zone.c
Jamie Gritton b38ff370e4 Introduce the extensible jail framework, using the same "name=value"
interface as nmount(2).  Three new system calls are added:
* jail_set, to create jails and change the parameters of existing jails.
  This replaces jail(2).
* jail_get, to read the parameters of existing jails.  This replaces the
  security.jail.list sysctl.
* jail_remove to kill off a jail's processes and remove the jail.
Most jail parameters may now be changed after creation, and jails may be
set to exist without any attached processes.  The current jail(2) system
call still exists, though it is now a stub to jail_set(2).

Approved by:	bz (mentor)
2009-04-29 21:14:15 +00:00

248 lines
6.2 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/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>
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 = priv_check_cred(cred, PRIV_ZFS_JAIL, 0)) != 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 = priv_check_cred(cred, PRIV_ZFS_JAIL, 0)) != 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(curthread)) {
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);
}
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);