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/*
27 * Common name validation routines for ZFS.  These routines are shared by the
28 * userland code as well as the ioctl() layer to ensure that we don't
29 * inadvertently expose a hole through direct ioctl()s that never gets tested.
30 * In userland, however, we want significantly more information about _why_ the
31 * name is invalid.  In the kernel, we only care whether it's valid or not.
32 * Each routine therefore takes a 'namecheck_err_t' which describes exactly why
33 * the name failed to validate.
34 *
35 * Each function returns 0 on success, -1 on error.
36 */
37
38#if defined(_KERNEL)
39#include <sys/systm.h>
40#else
41#include <string.h>
42#endif
43
44#include <sys/param.h>
45#include <sys/nvpair.h>
46#include "zfs_namecheck.h"
47#include "zfs_deleg.h"
48
49static int
50valid_char(char c)
51{
52	return ((c >= 'a' && c <= 'z') ||
53	    (c >= 'A' && c <= 'Z') ||
54	    (c >= '0' && c <= '9') ||
55	    c == '-' || c == '_' || c == '.' || c == ':' || c == ' ');
56}
57
58/*
59 * Snapshot names must be made up of alphanumeric characters plus the following
60 * characters:
61 *
62 * 	[-_.: ]
63 */
64int
65snapshot_namecheck(const char *path, namecheck_err_t *why, char *what)
66{
67	const char *loc;
68
69	if (strlen(path) >= MAXNAMELEN) {
70		if (why)
71			*why = NAME_ERR_TOOLONG;
72		return (-1);
73	}
74
75	if (path[0] == '\0') {
76		if (why)
77			*why = NAME_ERR_EMPTY_COMPONENT;
78		return (-1);
79	}
80
81	for (loc = path; *loc; loc++) {
82		if (!valid_char(*loc)) {
83			if (why) {
84				*why = NAME_ERR_INVALCHAR;
85				*what = *loc;
86			}
87			return (-1);
88		}
89	}
90	return (0);
91}
92
93
94/*
95 * Permissions set name must start with the letter '@' followed by the
96 * same character restrictions as snapshot names, except that the name
97 * cannot exceed 64 characters.
98 */
99int
100permset_namecheck(const char *path, namecheck_err_t *why, char *what)
101{
102	if (strlen(path) >= ZFS_PERMSET_MAXLEN) {
103		if (why)
104			*why = NAME_ERR_TOOLONG;
105		return (-1);
106	}
107
108	if (path[0] != '@') {
109		if (why) {
110			*why = NAME_ERR_NO_AT;
111			*what = path[0];
112		}
113		return (-1);
114	}
115
116	return (snapshot_namecheck(&path[1], why, what));
117}
118
119/*
120 * Dataset names must be of the following form:
121 *
122 * 	[component][/]*[component][@component]
123 *
124 * Where each component is made up of alphanumeric characters plus the following
125 * characters:
126 *
127 * 	[-_.:%]
128 *
129 * We allow '%' here as we use that character internally to create unique
130 * names for temporary clones (for online recv).
131 */
132int
133dataset_namecheck(const char *path, namecheck_err_t *why, char *what)
134{
135	const char *loc, *end;
136	int found_snapshot;
137
138	/*
139	 * Make sure the name is not too long.
140	 *
141	 * ZFS_MAXNAMELEN is the maximum dataset length used in the userland
142	 * which is the same as MAXNAMELEN used in the kernel.
143	 * If ZFS_MAXNAMELEN value is changed, make sure to cleanup all
144	 * places using MAXNAMELEN.
145	 */
146
147	if (strlen(path) >= MAXNAMELEN) {
148		if (why)
149			*why = NAME_ERR_TOOLONG;
150		return (-1);
151	}
152
153	/* Explicitly check for a leading slash.  */
154	if (path[0] == '/') {
155		if (why)
156			*why = NAME_ERR_LEADING_SLASH;
157		return (-1);
158	}
159
160	if (path[0] == '\0') {
161		if (why)
162			*why = NAME_ERR_EMPTY_COMPONENT;
163		return (-1);
164	}
165
166	loc = path;
167	found_snapshot = 0;
168	for (;;) {
169		/* Find the end of this component */
170		end = loc;
171		while (*end != '/' && *end != '@' && *end != '\0')
172			end++;
173
174		if (*end == '\0' && end[-1] == '/') {
175			/* trailing slashes are not allowed */
176			if (why)
177				*why = NAME_ERR_TRAILING_SLASH;
178			return (-1);
179		}
180
181		/* Zero-length components are not allowed */
182		if (loc == end) {
183			if (why) {
184				/*
185				 * Make sure this is really a zero-length
186				 * component and not a '@@'.
187				 */
188				if (*end == '@' && found_snapshot) {
189					*why = NAME_ERR_MULTIPLE_AT;
190				} else {
191					*why = NAME_ERR_EMPTY_COMPONENT;
192				}
193			}
194
195			return (-1);
196		}
197
198		/* Validate the contents of this component */
199		while (loc != end) {
200			if (!valid_char(*loc) && *loc != '%') {
201				if (why) {
202					*why = NAME_ERR_INVALCHAR;
203					*what = *loc;
204				}
205				return (-1);
206			}
207			loc++;
208		}
209
210		/* If we've reached the end of the string, we're OK */
211		if (*end == '\0')
212			return (0);
213
214		if (*end == '@') {
215			/*
216			 * If we've found an @ symbol, indicate that we're in
217			 * the snapshot component, and report a second '@'
218			 * character as an error.
219			 */
220			if (found_snapshot) {
221				if (why)
222					*why = NAME_ERR_MULTIPLE_AT;
223				return (-1);
224			}
225
226			found_snapshot = 1;
227		}
228
229		/*
230		 * If there is a '/' in a snapshot name
231		 * then report an error
232		 */
233		if (*end == '/' && found_snapshot) {
234			if (why)
235				*why = NAME_ERR_TRAILING_SLASH;
236			return (-1);
237		}
238
239		/* Update to the next component */
240		loc = end + 1;
241	}
242}
243
244
245/*
246 * mountpoint names must be of the following form:
247 *
248 *	/[component][/]*[component][/]
249 */
250int
251mountpoint_namecheck(const char *path, namecheck_err_t *why)
252{
253	const char *start, *end;
254
255	/*
256	 * Make sure none of the mountpoint component names are too long.
257	 * If a component name is too long then the mkdir of the mountpoint
258	 * will fail but then the mountpoint property will be set to a value
259	 * that can never be mounted.  Better to fail before setting the prop.
260	 * Extra slashes are OK, they will be tossed by the mountpoint mkdir.
261	 */
262
263	if (path == NULL || *path != '/') {
264		if (why)
265			*why = NAME_ERR_LEADING_SLASH;
266		return (-1);
267	}
268
269	/* Skip leading slash  */
270	start = &path[1];
271	do {
272		end = start;
273		while (*end != '/' && *end != '\0')
274			end++;
275
276		if (end - start >= MAXNAMELEN) {
277			if (why)
278				*why = NAME_ERR_TOOLONG;
279			return (-1);
280		}
281		start = end + 1;
282
283	} while (*end != '\0');
284
285	return (0);
286}
287
288/*
289 * For pool names, we have the same set of valid characters as described in
290 * dataset names, with the additional restriction that the pool name must begin
291 * with a letter.  The pool names 'raidz' and 'mirror' are also reserved names
292 * that cannot be used.
293 */
294int
295pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
296{
297	const char *c;
298
299	/*
300	 * Make sure the name is not too long.
301	 *
302	 * ZPOOL_MAXNAMELEN is the maximum pool length used in the userland
303	 * which is the same as MAXNAMELEN used in the kernel.
304	 * If ZPOOL_MAXNAMELEN value is changed, make sure to cleanup all
305	 * places using MAXNAMELEN.
306	 */
307	if (strlen(pool) >= MAXNAMELEN) {
308		if (why)
309			*why = NAME_ERR_TOOLONG;
310		return (-1);
311	}
312
313	c = pool;
314	while (*c != '\0') {
315		if (!valid_char(*c)) {
316			if (why) {
317				*why = NAME_ERR_INVALCHAR;
318				*what = *c;
319			}
320			return (-1);
321		}
322		c++;
323	}
324
325	if (!(*pool >= 'a' && *pool <= 'z') &&
326	    !(*pool >= 'A' && *pool <= 'Z')) {
327		if (why)
328			*why = NAME_ERR_NOLETTER;
329		return (-1);
330	}
331
332	if (strcmp(pool, "mirror") == 0 || strcmp(pool, "raidz") == 0) {
333		if (why)
334			*why = NAME_ERR_RESERVED;
335		return (-1);
336	}
337
338	if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
339		if (why)
340			*why = NAME_ERR_DISKLIKE;
341		return (-1);
342	}
343
344	return (0);
345}
346