1/*- 2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <sys/param.h> 31#include <sys/kernel.h> 32#include <sys/systm.h> 33#include <sys/proc.h> 34#include <sys/lock.h> 35#include <sys/mutex.h> 36#include <sys/sx.h> 37#include <sys/malloc.h> 38#include <sys/queue.h> 39#include <sys/jail.h> 40#include <sys/osd.h> 41#include <sys/priv.h> 42#include <sys/zone.h> 43 44static MALLOC_DEFINE(M_ZONES, "zones_data", "Zones data"); 45 46/* 47 * Structure to record list of ZFS datasets exported to a zone. 48 */ 49typedef struct zone_dataset { 50 LIST_ENTRY(zone_dataset) zd_next; 51 char zd_dataset[0]; 52} zone_dataset_t; 53 54LIST_HEAD(zone_dataset_head, zone_dataset); 55 56static int zone_slot; 57 58int 59zone_dataset_attach(struct ucred *cred, const char *dataset, int jailid) 60{ 61 struct zone_dataset_head *head; 62 zone_dataset_t *zd, *zd2; 63 struct prison *pr; 64 int dofree, error; 65 66 if ((error = priv_check_cred(cred, PRIV_ZFS_JAIL, 0)) != 0) 67 return (error); 68 69 /* Allocate memory before we grab prison's mutex. */ 70 zd = malloc(sizeof(*zd) + strlen(dataset) + 1, M_ZONES, M_WAITOK); 71 72 sx_slock(&allprison_lock); 73 pr = prison_find(jailid); /* Locks &pr->pr_mtx. */ 74 sx_sunlock(&allprison_lock); 75 if (pr == NULL) { 76 free(zd, M_ZONES); 77 return (ENOENT); 78 } 79 80 head = osd_jail_get(pr, zone_slot); 81 if (head != NULL) { 82 dofree = 0; 83 LIST_FOREACH(zd2, head, zd_next) { 84 if (strcmp(dataset, zd2->zd_dataset) == 0) { 85 free(zd, M_ZONES); 86 error = EEXIST; 87 goto end; 88 } 89 } 90 } else { 91 dofree = 1; 92 prison_hold_locked(pr); 93 mtx_unlock(&pr->pr_mtx); 94 head = malloc(sizeof(*head), M_ZONES, M_WAITOK); 95 LIST_INIT(head); 96 mtx_lock(&pr->pr_mtx); 97 error = osd_jail_set(pr, zone_slot, head); 98 KASSERT(error == 0, ("osd_jail_set() failed (error=%d)", error)); 99 } 100 strcpy(zd->zd_dataset, dataset); 101 LIST_INSERT_HEAD(head, zd, zd_next); 102end: 103 if (dofree) 104 prison_free_locked(pr); 105 else 106 mtx_unlock(&pr->pr_mtx); 107 return (error); 108} 109 110int 111zone_dataset_detach(struct ucred *cred, const char *dataset, int jailid) 112{ 113 struct zone_dataset_head *head; 114 zone_dataset_t *zd; 115 struct prison *pr; 116 int error; 117 118 if ((error = priv_check_cred(cred, PRIV_ZFS_JAIL, 0)) != 0) 119 return (error); 120 121 sx_slock(&allprison_lock); 122 pr = prison_find(jailid); 123 sx_sunlock(&allprison_lock); 124 if (pr == NULL) 125 return (ENOENT); 126 head = osd_jail_get(pr, zone_slot); 127 if (head == NULL) { 128 error = ENOENT; 129 goto end; 130 } 131 LIST_FOREACH(zd, head, zd_next) { 132 if (strcmp(dataset, zd->zd_dataset) == 0) 133 break; 134 } 135 if (zd == NULL) 136 error = ENOENT; 137 else { 138 LIST_REMOVE(zd, zd_next); 139 free(zd, M_ZONES); 140 if (LIST_EMPTY(head)) 141 osd_jail_del(pr, zone_slot); 142 error = 0; 143 } 144end: 145 mtx_unlock(&pr->pr_mtx); 146 return (error); 147} 148 149/* 150 * Returns true if the named dataset is visible in the current zone. 151 * The 'write' parameter is set to 1 if the dataset is also writable. 152 */ 153int 154zone_dataset_visible(const char *dataset, int *write) 155{ 156 struct zone_dataset_head *head; 157 zone_dataset_t *zd; 158 struct prison *pr; 159 size_t len; 160 int ret = 0; 161 162 if (dataset[0] == '\0') 163 return (0); 164 if (INGLOBALZONE(curthread)) { 165 if (write != NULL) 166 *write = 1; 167 return (1); 168 } 169 pr = curthread->td_ucred->cr_prison; 170 mtx_lock(&pr->pr_mtx); 171 head = osd_jail_get(pr, zone_slot); 172 if (head == NULL) 173 goto end; 174 175 /* 176 * Walk the list once, looking for datasets which match exactly, or 177 * specify a dataset underneath an exported dataset. If found, return 178 * true and note that it is writable. 179 */ 180 LIST_FOREACH(zd, head, zd_next) { 181 len = strlen(zd->zd_dataset); 182 if (strlen(dataset) >= len && 183 bcmp(dataset, zd->zd_dataset, len) == 0 && 184 (dataset[len] == '\0' || dataset[len] == '/' || 185 dataset[len] == '@')) { 186 if (write) 187 *write = 1; 188 ret = 1; 189 goto end; 190 } 191 } 192 193 /* 194 * Walk the list a second time, searching for datasets which are parents 195 * of exported datasets. These should be visible, but read-only. 196 * 197 * Note that we also have to support forms such as 'pool/dataset/', with 198 * a trailing slash. 199 */ 200 LIST_FOREACH(zd, head, zd_next) { 201 len = strlen(dataset); 202 if (dataset[len - 1] == '/') 203 len--; /* Ignore trailing slash */ 204 if (len < strlen(zd->zd_dataset) && 205 bcmp(dataset, zd->zd_dataset, len) == 0 && 206 zd->zd_dataset[len] == '/') { 207 if (write) 208 *write = 0; 209 ret = 1; 210 goto end; 211 } 212 } 213end: 214 mtx_unlock(&pr->pr_mtx); 215 return (ret); 216} 217 218static void 219zone_destroy(void *arg) 220{ 221 struct zone_dataset_head *head; 222 zone_dataset_t *zd; 223 224 head = arg; 225 while ((zd = LIST_FIRST(head)) != NULL) { 226 LIST_REMOVE(zd, zd_next); 227 free(zd, M_ZONES); 228 } 229 free(head, M_ZONES); 230} 231 232uint32_t 233zone_get_hostid(void *ptr) 234{ 235 236 KASSERT(ptr == NULL, ("only NULL pointer supported in %s", __func__)); 237 238 return ((uint32_t)curthread->td_ucred->cr_prison->pr_hostid); 239} 240 241static void 242zone_sysinit(void *arg __unused) 243{ 244 245 zone_slot = osd_jail_register(zone_destroy, NULL); 246} 247 248static void 249zone_sysuninit(void *arg __unused) 250{ 251 252 osd_jail_deregister(zone_slot); 253} 254 255SYSINIT(zone_sysinit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysinit, NULL); 256SYSUNINIT(zone_sysuninit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysuninit, NULL); 257