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 * 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
entity_namecheck(const char * path,namecheck_err_t * why,char * what)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
dataset_namecheck(const char * path,namecheck_err_t * why,char * what)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
mountpoint_namecheck(const char * path,namecheck_err_t * why)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
pool_namecheck(const char * pool,namecheck_err_t * why,char * what)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 }
344