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/types.h> 28 #include <sys/param.h> 29 #include <sys/kernel.h> 30 #include <sys/systm.h> 31 #include <sys/proc.h> 32 #include <sys/lock.h> 33 #include <sys/mutex.h> 34 #include <sys/sx.h> 35 #include <sys/malloc.h> 36 #include <sys/queue.h> 37 #include <sys/jail.h> 38 #include <sys/osd.h> 39 #include <sys/priv.h> 40 #include <sys/zone.h> 41 42 #include <sys/policy.h> 43 44 static MALLOC_DEFINE(M_ZONES, "zones_data", "Zones data"); 45 46 /* 47 * Structure to record list of ZFS datasets exported to a zone. 48 */ 49 typedef struct zone_dataset { 50 LIST_ENTRY(zone_dataset) zd_next; 51 char zd_dataset[0]; 52 } zone_dataset_t; 53 54 LIST_HEAD(zone_dataset_head, zone_dataset); 55 56 static int zone_slot; 57 58 int 59 zone_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 = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 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)", 99 error)); 100 } 101 strcpy(zd->zd_dataset, dataset); 102 LIST_INSERT_HEAD(head, zd, zd_next); 103 end: 104 if (dofree) 105 prison_free_locked(pr); 106 else 107 mtx_unlock(&pr->pr_mtx); 108 return (error); 109 } 110 111 int 112 zone_dataset_detach(struct ucred *cred, const char *dataset, int jailid) 113 { 114 struct zone_dataset_head *head; 115 zone_dataset_t *zd; 116 struct prison *pr; 117 int error; 118 119 if ((error = spl_priv_check_cred(cred, PRIV_ZFS_JAIL)) != 0) 120 return (error); 121 122 sx_slock(&allprison_lock); 123 pr = prison_find(jailid); 124 sx_sunlock(&allprison_lock); 125 if (pr == NULL) 126 return (ENOENT); 127 head = osd_jail_get(pr, zone_slot); 128 if (head == NULL) { 129 error = ENOENT; 130 goto end; 131 } 132 LIST_FOREACH(zd, head, zd_next) { 133 if (strcmp(dataset, zd->zd_dataset) == 0) 134 break; 135 } 136 if (zd == NULL) 137 error = ENOENT; 138 else { 139 LIST_REMOVE(zd, zd_next); 140 free(zd, M_ZONES); 141 if (LIST_EMPTY(head)) 142 osd_jail_del(pr, zone_slot); 143 error = 0; 144 } 145 end: 146 mtx_unlock(&pr->pr_mtx); 147 return (error); 148 } 149 150 /* 151 * Returns true if the named dataset is visible in the current zone. 152 * The 'write' parameter is set to 1 if the dataset is also writable. 153 */ 154 int 155 zone_dataset_visible(const char *dataset, int *write) 156 { 157 struct zone_dataset_head *head; 158 zone_dataset_t *zd; 159 struct prison *pr; 160 size_t len; 161 int ret = 0; 162 163 if (dataset[0] == '\0') 164 return (0); 165 if (INGLOBALZONE(curproc)) { 166 if (write != NULL) 167 *write = 1; 168 return (1); 169 } 170 pr = curthread->td_ucred->cr_prison; 171 mtx_lock(&pr->pr_mtx); 172 head = osd_jail_get(pr, zone_slot); 173 if (head == NULL) 174 goto end; 175 176 /* 177 * Walk the list once, looking for datasets which match exactly, or 178 * specify a dataset underneath an exported dataset. If found, return 179 * true and note that it is writable. 180 */ 181 LIST_FOREACH(zd, head, zd_next) { 182 len = strlen(zd->zd_dataset); 183 if (strlen(dataset) >= len && 184 memcmp(dataset, zd->zd_dataset, len) == 0 && 185 (dataset[len] == '\0' || dataset[len] == '/' || 186 dataset[len] == '@')) { 187 if (write) 188 *write = 1; 189 ret = 1; 190 goto end; 191 } 192 } 193 194 /* 195 * Walk the list a second time, searching for datasets which are parents 196 * of exported datasets. These should be visible, but read-only. 197 * 198 * Note that we also have to support forms such as 'pool/dataset/', with 199 * a trailing slash. 200 */ 201 LIST_FOREACH(zd, head, zd_next) { 202 len = strlen(dataset); 203 if (dataset[len - 1] == '/') 204 len--; /* Ignore trailing slash */ 205 if (len < strlen(zd->zd_dataset) && 206 memcmp(dataset, zd->zd_dataset, len) == 0 && 207 zd->zd_dataset[len] == '/') { 208 if (write) 209 *write = 0; 210 ret = 1; 211 goto end; 212 } 213 } 214 end: 215 mtx_unlock(&pr->pr_mtx); 216 return (ret); 217 } 218 219 static void 220 zone_destroy(void *arg) 221 { 222 struct zone_dataset_head *head; 223 zone_dataset_t *zd; 224 225 head = arg; 226 while ((zd = LIST_FIRST(head)) != NULL) { 227 LIST_REMOVE(zd, zd_next); 228 free(zd, M_ZONES); 229 } 230 free(head, M_ZONES); 231 } 232 233 uint32_t 234 zone_get_hostid(void *ptr) 235 { 236 237 KASSERT(ptr == NULL, ("only NULL pointer supported in %s", __func__)); 238 239 return ((uint32_t)curthread->td_ucred->cr_prison->pr_hostid); 240 } 241 242 static void 243 zone_sysinit(void *arg __unused) 244 { 245 246 zone_slot = osd_jail_register(zone_destroy, NULL); 247 } 248 249 static void 250 zone_sysuninit(void *arg __unused) 251 { 252 253 osd_jail_deregister(zone_slot); 254 } 255 256 SYSINIT(zone_sysinit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysinit, NULL); 257 SYSUNINIT(zone_sysuninit, SI_SUB_DRIVERS, SI_ORDER_ANY, zone_sysuninit, NULL); 258