usr/src/common/zfs/zfs_namecheck.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright (c) 2013 by Delphix. All rights reserved.
  27  */
  28
  29 /*
  30  * Common name validation routines for ZFS.  These routines are shared by the
  31  * userland code as well as the ioctl() layer to ensure that we don't
  32  * inadvertently expose a hole through direct ioctl()s that never gets tested.
  33  * In userland, however, we want significantly more information about _why_ the
  34  * name is invalid.  In the kernel, we only care whether it's valid or not.
  35  * Each routine therefore takes a 'namecheck_err_t' which describes exactly why
  36  * the name failed to validate.
  37  *
  38  * Each function returns 0 on success, -1 on error.
  39  */
  40
  41 #if defined(_KERNEL)
  42 #include <sys/systm.h>
  43 #else
  44 #include <string.h>
  45 #endif
  46
  47 #include <sys/param.h>
  48 #include <sys/nvpair.h>
  49 #include "zfs_namecheck.h"
  50 #include "zfs_deleg.h"
  51
  52 static int
  53 valid_char(char c)
  54 {
  55         return ((c >= 'a' && c <= 'z') ||
  56             (c >= 'A' && c <= 'Z') ||
  57             (c >= '0' && c <= '9') ||
  58             c == '-' || c == '_' || c == '.' || c == ':' || c == ' ');
  59 }
  60
  61 /*
  62  * Snapshot names must be made up of alphanumeric characters plus the following
  63  * characters:
  64  *
  65  *      [-_.: ]
  66  */
  67 int
  68 zfs_component_namecheck(const char *path, namecheck_err_t *why, char *what)
  69 {
  70         const char *loc;
  71
  72         if (strlen(path) >= ZFS_MAX_DATASET_NAME_LEN) {
  73                 if (why)
  74                         *why = NAME_ERR_TOOLONG;
  75                 return (-1);
  76         }
  77
  78         if (path[0] == '\0') {
  79                 if (why)
  80                         *why = NAME_ERR_EMPTY_COMPONENT;
  81                 return (-1);
  82         }
  83
  84         for (loc = path; *loc; loc++) {
  85                 if (!valid_char(*loc)) {
  86                         if (why) {
  87                                 *why = NAME_ERR_INVALCHAR;
  88                                 *what = *loc;
  89                         }
  90                         return (-1);
  91                 }
  92         }
  93         return (0);
  94 }
  95
  96
  97 /*
  98  * Permissions set name must start with the letter '@' followed by the
  99  * same character restrictions as snapshot names, except that the name
 100  * cannot exceed 64 characters.
 101  */
 102 int
 103 permset_namecheck(const char *path, namecheck_err_t *why, char *what)
 104 {
 105         if (strlen(path) >= ZFS_PERMSET_MAXLEN) {
 106                 if (why)
 107                         *why = NAME_ERR_TOOLONG;
 108                 return (-1);
 109         }
 110
 111         if (path[0] != '@') {
 112                 if (why) {
 113                         *why = NAME_ERR_NO_AT;
 114                         *what = path[0];
 115                 }
 116                 return (-1);
 117         }
 118
 119         return (zfs_component_namecheck(&path[1], why, what));
 120 }
 121
 122 /*
 123  * Entity names must be of the following form:
 124  *
 125  *      [component/]*[component][(@|#)component]?
 126  *
 127  * Where each component is made up of alphanumeric characters plus the following
 128  * characters:
 129  *
 130  *      [-_.:%]
 131  *
 132  * We allow '%' here as we use that character internally to create unique
 133  * names for temporary clones (for online recv).
 134  */
 135 int
 136 entity_namecheck(const char *path, namecheck_err_t *why, char *what)
 137 {
 138         const char *start, *end;
 139         int found_delim;
 140
 141         /*
 142          * Make sure the name is not too long.
 143          */
 144
 145         if (strlen(path) >= ZFS_MAX_DATASET_NAME_LEN) {
 146                 if (why)
 147                         *why = NAME_ERR_TOOLONG;
 148                 return (-1);
 149         }
 150
 151         /* Explicitly check for a leading slash.  */
 152         if (path[0] == '/') {
 153                 if (why)
 154                         *why = NAME_ERR_LEADING_SLASH;
 155                 return (-1);
 156         }
 157
 158         if (path[0] == '\0') {
 159                 if (why)
 160                         *why = NAME_ERR_EMPTY_COMPONENT;
 161                 return (-1);
 162         }
 163
 164         start = path;
 165         found_delim = 0;
 166         for (;;) {
 167                 /* Find the end of this component */
 168                 end = start;
 169                 while (*end != '/' && *end != '@' && *end != '#' &&
 170                     *end != '\0')
 171                         end++;
 172
 173                 if (*end == '\0' && end[-1] == '/') {
 174                         /* trailing slashes are not allowed */
 175                         if (why)
 176                                 *why = NAME_ERR_TRAILING_SLASH;
 177                         return (-1);
 178                 }
 179
 180                 /* Validate the contents of this component */
 181                 for (const char *loc = start; loc != end; loc++) {
 182                         if (!valid_char(*loc) && *loc != '%') {
 183                                 if (why) {
 184                                         *why = NAME_ERR_INVALCHAR;
 185                                         *what = *loc;
 186                                 }
 187                                 return (-1);
 188                         }
 189                 }
 190
 191                 /* Snapshot or bookmark delimiter found */
 192                 if (*end == '@' || *end == '#') {
 193                         /* Multiple delimiters are not allowed */
 194                         if (found_delim != 0) {
 195                                 if (why)
 196                                         *why = NAME_ERR_MULTIPLE_DELIMITERS;
 197                                 return (-1);
 198                         }
 199
 200                         found_delim = 1;
 201                 }
 202
 203                 /* Zero-length components are not allowed */
 204                 if (start == end) {
 205                         if (why)
 206                                 *why = NAME_ERR_EMPTY_COMPONENT;
 207                         return (-1);
 208                 }
 209
 210                 /* If we've reached the end of the string, we're OK */
 211                 if (*end == '\0')
 212                         return (0);
 213
 214                 /*
 215                  * If there is a '/' in a snapshot or bookmark name
 216                  * then report an error
 217                  */
 218                 if (*end == '/' && found_delim != 0) {
 219                         if (why)
 220                                 *why = NAME_ERR_TRAILING_SLASH;
 221                         return (-1);
 222                 }
 223
 224                 /* Update to the next component */
 225                 start = end + 1;
 226         }
 227 }
 228
 229 /*
 230  * Dataset is any entity, except bookmark
 231  */
 232 int
 233 dataset_namecheck(const char *path, namecheck_err_t *why, char *what)
 234 {
 235         int ret = entity_namecheck(path, why, what);
 236
 237         if (ret == 0 && strchr(path, '#') != NULL) {
 238                 if (why != NULL) {
 239                         *why = NAME_ERR_INVALCHAR;
 240                         *what = '#';
 241                 }
 242                 return (-1);
 243         }
 244
 245         return (ret);
 246 }
 247
 248 /*
 249  * mountpoint names must be of the following form:
 250  *
 251  *      /[component][/]*[component][/]
 252  */
 253 int
 254 mountpoint_namecheck(const char *path, namecheck_err_t *why)
 255 {
 256         const char *start, *end;
 257
 258         /*
 259          * Make sure none of the mountpoint component names are too long.
 260          * If a component name is too long then the mkdir of the mountpoint
 261          * will fail but then the mountpoint property will be set to a value
 262          * that can never be mounted.  Better to fail before setting the prop.
 263          * Extra slashes are OK, they will be tossed by the mountpoint mkdir.
 264          */
 265
 266         if (path == NULL || *path != '/') {
 267                 if (why)
 268                         *why = NAME_ERR_LEADING_SLASH;
 269                 return (-1);
 270         }
 271
 272         /* Skip leading slash  */
 273         start = &path[1];
 274         do {
 275                 end = start;
 276                 while (*end != '/' && *end != '\0')
 277                         end++;
 278
 279                 if (end - start >= ZFS_MAX_DATASET_NAME_LEN) {
 280                         if (why)
 281                                 *why = NAME_ERR_TOOLONG;
 282                         return (-1);
 283                 }
 284                 start = end + 1;
 285
 286         } while (*end != '\0');
 287
 288         return (0);
 289 }
 290
 291 /*
 292  * For pool names, we have the same set of valid characters as described in
 293  * dataset names, with the additional restriction that the pool name must begin
 294  * with a letter.  The pool names 'raidz' and 'mirror' are also reserved names
 295  * that cannot be used.
 296  */
 297 int
 298 pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
 299 {
 300         const char *c;
 301
 302         /*
 303          * Make sure the name is not too long.
 304          */
 305         if (strlen(pool) >= ZFS_MAX_DATASET_NAME_LEN) {
 306                 if (why)
 307                         *why = NAME_ERR_TOOLONG;
 308                 return (-1);
 309         }
 310
 311         c = pool;
 312         while (*c != '\0') {
 313                 if (!valid_char(*c)) {
 314                         if (why) {
 315                                 *why = NAME_ERR_INVALCHAR;
 316                                 *what = *c;
 317                         }
 318                         return (-1);
 319                 }
 320                 c++;
 321         }
 322
 323         if (!(*pool >= 'a' && *pool <= 'z') &&
 324             !(*pool >= 'A' && *pool <= 'Z')) {
 325                 if (why)
 326                         *why = NAME_ERR_NOLETTER;
 327                 return (-1);
 328         }
 329
 330         if (strcmp(pool, "mirror") == 0 || strcmp(pool, "raidz") == 0) {
 331                 if (why)
 332                         *why = NAME_ERR_RESERVED;
 333                 return (-1);
 334         }
 335
 336         if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
 337                 if (why)
 338                         *why = NAME_ERR_DISKLIKE;
 339                 return (-1);
 340         }
 341
 342         return (0);
 343 }