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
valid_char(char c)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
zfs_component_namecheck(const char * path,namecheck_err_t * why,char * what)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
permset_namecheck(const char * path,namecheck_err_t * why,char * what)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 * Dataset 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
dataset_namecheck(const char * path,namecheck_err_t * why,char * what)136 dataset_namecheck(const char *path, namecheck_err_t *why, char *what)
137 {
138 const char *loc, *end;
139 int found_snapshot;
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 loc = path;
165 found_snapshot = 0;
166 for (;;) {
167 /* Find the end of this component */
168 end = loc;
169 while (*end != '/' && *end != '@' && *end != '\0')
170 end++;
171
172 if (*end == '\0' && end[-1] == '/') {
173 /* trailing slashes are not allowed */
174 if (why)
175 *why = NAME_ERR_TRAILING_SLASH;
176 return (-1);
177 }
178
179 /* Zero-length components are not allowed */
180 if (loc == end) {
181 if (why) {
182 /*
183 * Make sure this is really a zero-length
184 * component and not a '@@'.
185 */
186 if (*end == '@' && found_snapshot) {
187 *why = NAME_ERR_MULTIPLE_AT;
188 } else {
189 *why = NAME_ERR_EMPTY_COMPONENT;
190 }
191 }
192
193 return (-1);
194 }
195
196 /* Validate the contents of this component */
197 while (loc != end) {
198 if (!valid_char(*loc) && *loc != '%') {
199 if (why) {
200 *why = NAME_ERR_INVALCHAR;
201 *what = *loc;
202 }
203 return (-1);
204 }
205 loc++;
206 }
207
208 /* If we've reached the end of the string, we're OK */
209 if (*end == '\0')
210 return (0);
211
212 if (*end == '@') {
213 /*
214 * If we've found an @ symbol, indicate that we're in
215 * the snapshot component, and report a second '@'
216 * character as an error.
217 */
218 if (found_snapshot) {
219 if (why)
220 *why = NAME_ERR_MULTIPLE_AT;
221 return (-1);
222 }
223
224 found_snapshot = 1;
225 }
226
227 /*
228 * If there is a '/' in a snapshot name
229 * then report an error
230 */
231 if (*end == '/' && found_snapshot) {
232 if (why)
233 *why = NAME_ERR_TRAILING_SLASH;
234 return (-1);
235 }
236
237 /* Update to the next component */
238 loc = end + 1;
239 }
240 }
241
242
243 /*
244 * mountpoint names must be of the following form:
245 *
246 * /[component][/]*[component][/]
247 */
248 int
mountpoint_namecheck(const char * path,namecheck_err_t * why)249 mountpoint_namecheck(const char *path, namecheck_err_t *why)
250 {
251 const char *start, *end;
252
253 /*
254 * Make sure none of the mountpoint component names are too long.
255 * If a component name is too long then the mkdir of the mountpoint
256 * will fail but then the mountpoint property will be set to a value
257 * that can never be mounted. Better to fail before setting the prop.
258 * Extra slashes are OK, they will be tossed by the mountpoint mkdir.
259 */
260
261 if (path == NULL || *path != '/') {
262 if (why)
263 *why = NAME_ERR_LEADING_SLASH;
264 return (-1);
265 }
266
267 /* Skip leading slash */
268 start = &path[1];
269 do {
270 end = start;
271 while (*end != '/' && *end != '\0')
272 end++;
273
274 if (end - start >= ZFS_MAX_DATASET_NAME_LEN) {
275 if (why)
276 *why = NAME_ERR_TOOLONG;
277 return (-1);
278 }
279 start = end + 1;
280
281 } while (*end != '\0');
282
283 return (0);
284 }
285
286 /*
287 * For pool names, we have the same set of valid characters as described in
288 * dataset names, with the additional restriction that the pool name must begin
289 * with a letter. The pool names 'raidz' and 'mirror' are also reserved names
290 * that cannot be used.
291 */
292 int
pool_namecheck(const char * pool,namecheck_err_t * why,char * what)293 pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
294 {
295 const char *c;
296
297 /*
298 * Make sure the name is not too long.
299 */
300 if (strlen(pool) >= ZFS_MAX_DATASET_NAME_LEN) {
301 if (why)
302 *why = NAME_ERR_TOOLONG;
303 return (-1);
304 }
305
306 c = pool;
307 while (*c != '\0') {
308 if (!valid_char(*c)) {
309 if (why) {
310 *why = NAME_ERR_INVALCHAR;
311 *what = *c;
312 }
313 return (-1);
314 }
315 c++;
316 }
317
318 if (!(*pool >= 'a' && *pool <= 'z') &&
319 !(*pool >= 'A' && *pool <= 'Z')) {
320 if (why)
321 *why = NAME_ERR_NOLETTER;
322 return (-1);
323 }
324
325 if (strcmp(pool, "mirror") == 0 || strcmp(pool, "raidz") == 0) {
326 if (why)
327 *why = NAME_ERR_RESERVED;
328 return (-1);
329 }
330
331 if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
332 if (why)
333 *why = NAME_ERR_DISKLIKE;
334 return (-1);
335 }
336
337 return (0);
338 }
339