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/types.h> 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/systm.h> 34 #include <sys/proc.h> 35 #include <sys/lock.h> 36 #include <sys/mutex.h> 37 #include <sys/sx.h> 38 #include <sys/malloc.h> 39 #include <sys/queue.h> 40 #include <sys/jail.h> 41 #include <sys/osd.h> 42 #include <sys/priv.h> 43 #include <sys/zone.h> 44 45 #include <sys/policy.h> 46 47 static MALLOC_DEFINE(M_ZONES, "zones_data", "Zones data"); 48 49 /* 50 * Structure to record list of ZFS datasets exported to a zone. 51 */ 52 typedef struct zone_dataset { 53 LIST_ENTRY(zone_dataset) zd_next; 54 char zd_dataset[0]; 55 } zone_dataset_t; 56 57 LIST_HEAD(zone_dataset_head, zone_dataset); 58 59 static int zone_slot; 60 61 int 62 zone_dataset_attach(struct ucred *cred, const char *dataset, int jailid) 63 { 64 struct zone_dataset_head *head; 65 zone_dataset_t *zd, *zd2; 66 struct prison *pr; 67 int dofree, error; 68 69 if ((error = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 0) 70 return (error); 71 72 /* Allocate memory before we grab prison's mutex. */ 73 zd = malloc(sizeof (*zd) + strlen(dataset) + 1, M_ZONES, M_WAITOK); 74 75 sx_slock(&allprison_lock); 76 pr = prison_find(jailid); /* Locks &pr->pr_mtx. */ 77 sx_sunlock(&allprison_lock); 78 if (pr == NULL) { 79 free(zd, M_ZONES); 80 return (ENOENT); 81 } 82 83 head = osd_jail_get(pr, zone_slot); 84 if (head != NULL) { 85 dofree = 0; 86 LIST_FOREACH(zd2, head, zd_next) { 87 if (strcmp(dataset, zd2->zd_dataset) == 0) { 88 free(zd, M_ZONES); 89 error = EEXIST; 90 goto end; 91 } 92 } 93 } else { 94 dofree = 1; 95 prison_hold_locked(pr); 96 mtx_unlock(&pr->pr_mtx); 97 head = malloc(sizeof (*head), M_ZONES, M_WAITOK); 98 LIST_INIT(head); 99 mtx_lock(&pr->pr_mtx); 100 error = osd_jail_set(pr, zone_slot, head); 101 KASSERT(error == 0, ("osd_jail_set() failed (error=%d)", 102 error)); 103 } 104 strcpy(zd->zd_dataset, dataset); 105 LIST_INSERT_HEAD(head, zd, zd_next); 106 end: 107 if (dofree) 108 prison_free_locked(pr); 109 else 110 mtx_unlock(&pr->pr_mtx); 111 return (error); 112 } 113 114 int 115 zone_dataset_detach(struct ucred *cred, const char *dataset, int jailid) 116 { 117 struct zone_dataset_head *head; 118 zone_dataset_t *zd; 119 struct prison *pr; 120 int error; 121 122 if ((error = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 0) 123 return (error); 124 125 sx_slock(&allprison_lock); 126 pr = prison_find(jailid); 127 sx_sunlock(&allprison_lock); 128 if (pr == NULL) 129 return (ENOENT); 130 head = osd_jail_get(pr, zone_slot); 131 if (head == NULL) { 132 error = ENOENT; 133 goto end; 134 } 135 LIST_FOREACH(zd, head, zd_next) { 136 if (strcmp(dataset, zd->zd_dataset) == 0) 137 break; 138 } 139 if (zd == NULL) 140 error = ENOENT; 141 else { 142 LIST_REMOVE(zd, zd_next); 143 free(zd, M_ZONES); 144 if (LIST_EMPTY(head)) 145 osd_jail_del(pr, zone_slot); 146 error = 0; 147 } 148 end: 149 mtx_unlock(&pr->pr_mtx); 150 return (error); 151 } 152 153 /* 154 * Returns true if the named dataset is visible in the current zone. 155 * The 'write' parameter is set to 1 if the dataset is also writable. 156 */ 157 int 158 zone_dataset_visible(const char *dataset, int *write) 159 { 160 struct zone_dataset_head *head; 161 zone_dataset_t *zd; 162 struct prison *pr; 163 size_t len; 164 int ret = 0; 165 166 if (dataset[0] == '\0') 167 return (0); 168 if (INGLOBALZONE(curproc)) { 169 if (write != NULL) 170 *write = 1; 171 return (1); 172 } 173 pr = curthread->td_ucred->cr_prison; 174 mtx_lock(&pr->pr_mtx); 175 head = osd_jail_get(pr, zone_slot); 176 if (head == NULL) 177 goto end; 178 179 /* 180 * Walk the list once, looking for datasets which match exactly, or 181 * specify a dataset underneath an exported dataset. If found, return 182 * true and note that it is writable. 183 */ 184 LIST_FOREACH(zd, head, zd_next) { 185 len = strlen(zd->zd_dataset); 186 if (strlen(dataset) >= len && 187 memcmp(dataset, zd->zd_dataset, len) == 0 && 188 (dataset[len] == '\0' || dataset[len] == '/' || 189 dataset[len] == '@')) { 190 if (write) 191 *write = 1; 192 ret = 1; 193 goto end; 194 } 195 } 196 197 /* 198 * Walk the list a second time, searching for datasets which are parents 199 * of exported datasets. These should be visible, but read-only. 200 * 201 * Note that we also have to support forms such as 'pool/dataset/', with 202 * a trailing slash. 203 */ 204 LIST_FOREACH(zd, head, zd_next) { 205 len = strlen(dataset); 206 if (dataset[len - 1] == '/') 207 len--; /* Ignore trailing slash */ 208 if (len < strlen(zd->zd_dataset) && 209 memcmp(dataset, zd->zd_dataset, len) == 0 && 210 zd->zd_dataset[len] == '/') { 211 if (write) 212 *write = 0; 213 ret = 1; 214 goto end; 215 } 216 } 217 end: 218 mtx_unlock(&pr->pr_mtx); 219 return (ret); 220 } 221 222 static void 223 zone_destroy(void *arg) 224 { 225 struct zone_dataset_head *head; 226 zone_dataset_t *zd; 227 228 head = arg; 229 while ((zd = LIST_FIRST(head)) != NULL) { 230 LIST_REMOVE(zd, zd_next); 231 free(zd, M_ZONES); 232 } 233 free(head, M_ZONES); 234 } 235 236 uint32_t 237 zone_get_hostid(void *ptr) 238 { 239 240 KASSERT(ptr == NULL, ("only NULL pointer supported in %s", __func__)); 241 242 return ((uint32_t)curthread->td_ucred->cr_prison->pr_hostid); 243 } 244 245 static void 246 zone_sysinit(void *arg __unused) 247 { 248 249 zone_slot = osd_jail_register(zone_destroy, NULL); 250 } 251 252 static void 253 zone_sysuninit(void *arg __unused) 254 { 255 256 osd_jail_deregister(zone_slot); 257 } 258 259 SYSINIT(zone_sysinit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysinit, NULL); 260 SYSUNINIT(zone_sysuninit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysuninit, NULL); 261