[mirror_zfs.git] / module / zcommon / zfs_namecheck.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Common name validation routines for ZFS.  These routines are shared by the
 * userland code as well as the ioctl() layer to ensure that we don't
 * inadvertently expose a hole through direct ioctl()s that never gets tested.
 * In userland, however, we want significantly more information about _why_ the
 * name is invalid.  In the kernel, we only care whether it's valid or not.
 * Each routine therefore takes a 'namecheck_err_t' which describes exactly why
 * the name failed to validate.
 *
 * Each function returns 0 on success, -1 on error.
 */

#if defined(_KERNEL)
#include <sys/systm.h>
#else
#include <string.h>
#endif

#include <sys/param.h>
#include <sys/nvpair.h>
#include "zfs_namecheck.h"
#include "zfs_deleg.h"

static int
valid_char(char c)
{
	return ((c >= 'a' && c <= 'z') ||
	    (c >= 'A' && c <= 'Z') ||
	    (c >= '0' && c <= '9') ||
	    c == '-' || c == '_' || c == '.' || c == ':' || c == ' ');
}

/*
 * Snapshot names must be made up of alphanumeric characters plus the following
 * characters:
 *
 * 	[-_.: ]
 */
int
snapshot_namecheck(const char *path, namecheck_err_t *why, char *what)
{
	const char *loc;

	if (strlen(path) >= MAXNAMELEN) {
		if (why)
			*why = NAME_ERR_TOOLONG;
		return (-1);
	}

	if (path[0] == '\0') {
		if (why)
			*why = NAME_ERR_EMPTY_COMPONENT;
		return (-1);
	}

	for (loc = path; *loc; loc++) {
		if (!valid_char(*loc)) {
			if (why) {
				*why = NAME_ERR_INVALCHAR;
				*what = *loc;
			}
			return (-1);
		}
	}
	return (0);
}


/*
 * Permissions set name must start with the letter '@' followed by the
 * same character restrictions as snapshot names, except that the name
 * cannot exceed 64 characters.
 */
int
permset_namecheck(const char *path, namecheck_err_t *why, char *what)
{
	if (strlen(path) >= ZFS_PERMSET_MAXLEN) {
		if (why)
			*why = NAME_ERR_TOOLONG;
		return (-1);
	}

	if (path[0] != '@') {
		if (why) {
			*why = NAME_ERR_NO_AT;
			*what = path[0];
		}
		return (-1);
	}

	return (snapshot_namecheck(&path[1], why, what));
}

/*
 * Dataset names must be of the following form:
 *
 * 	[component][/]*[component][@component]
 *
 * Where each component is made up of alphanumeric characters plus the following
 * characters:
 *
 * 	[-_.:%]
 *
 * We allow '%' here as we use that character internally to create unique
 * names for temporary clones (for online recv).
 */
int
dataset_namecheck(const char *path, namecheck_err_t *why, char *what)
{
	const char *loc, *end;
	int found_snapshot;

	/*
	 * Make sure the name is not too long.
	 *
	 * ZFS_MAXNAMELEN is the maximum dataset length used in the userland
	 * which is the same as MAXNAMELEN used in the kernel.
	 * If ZFS_MAXNAMELEN value is changed, make sure to cleanup all
	 * places using MAXNAMELEN.
	 *
	 * When HAVE_KOBJ_NAME_LEN is defined the maximum safe kobject name
	 * length is 20 bytes.  This 20 bytes is broken down as follows to
	 * provide a maximum safe <pool>/<dataset>[@snapshot] length of only
	 * 18 bytes.  To ensure bytes are left for <dataset>[@snapshot] the
	 * <pool> portition is futher limited to 9 bytes.  For 2.6.27 and
	 * newer kernels this limit is set to MAXNAMELEN.
	 *
	 *   <pool>/<dataset> + <partition> + <newline>
	 *   (18)             + (1)         + (1)
	 */
#ifdef HAVE_KOBJ_NAME_LEN
	if (strlen(path) > 18) {
#else
	if (strlen(path) >= MAXNAMELEN) {
#endif /* HAVE_KOBJ_NAME_LEN */
		if (why)
			*why = NAME_ERR_TOOLONG;
		return (-1);
	}

	/* Explicitly check for a leading slash.  */
	if (path[0] == '/') {
		if (why)
			*why = NAME_ERR_LEADING_SLASH;
		return (-1);
	}

	if (path[0] == '\0') {
		if (why)
			*why = NAME_ERR_EMPTY_COMPONENT;
		return (-1);
	}

	loc = path;
	found_snapshot = 0;
	for (;;) {
		/* Find the end of this component */
		end = loc;
		while (*end != '/' && *end != '@' && *end != '\0')
			end++;

		if (*end == '\0' && end[-1] == '/') {
			/* trailing slashes are not allowed */
			if (why)
				*why = NAME_ERR_TRAILING_SLASH;
			return (-1);
		}

		/* Zero-length components are not allowed */
		if (loc == end) {
			if (why) {
				/*
				 * Make sure this is really a zero-length
				 * component and not a '@@'.
				 */
				if (*end == '@' && found_snapshot) {
					*why = NAME_ERR_MULTIPLE_AT;
				} else {
					*why = NAME_ERR_EMPTY_COMPONENT;
				}
			}

			return (-1);
		}

		/* Validate the contents of this component */
		while (loc != end) {
			if (!valid_char(*loc) && *loc != '%') {
				if (why) {
					*why = NAME_ERR_INVALCHAR;
					*what = *loc;
				}
				return (-1);
			}
			loc++;
		}

		/* If we've reached the end of the string, we're OK */
		if (*end == '\0')
			return (0);

		if (*end == '@') {
			/*
			 * If we've found an @ symbol, indicate that we're in
			 * the snapshot component, and report a second '@'
			 * character as an error.
			 */
			if (found_snapshot) {
				if (why)
					*why = NAME_ERR_MULTIPLE_AT;
				return (-1);
			}

			found_snapshot = 1;
		}

		/*
		 * If there is a '/' in a snapshot name
		 * then report an error
		 */
		if (*end == '/' && found_snapshot) {
			if (why)
				*why = NAME_ERR_TRAILING_SLASH;
			return (-1);
		}

		/* Update to the next component */
		loc = end + 1;
	}
}


/*
 * mountpoint names must be of the following form:
 *
 *	/[component][/]*[component][/]
 */
int
mountpoint_namecheck(const char *path, namecheck_err_t *why)
{
	const char *start, *end;

	/*
	 * Make sure none of the mountpoint component names are too long.
	 * If a component name is too long then the mkdir of the mountpoint
	 * will fail but then the mountpoint property will be set to a value
	 * that can never be mounted.  Better to fail before setting the prop.
	 * Extra slashes are OK, they will be tossed by the mountpoint mkdir.
	 */

	if (path == NULL || *path != '/') {
		if (why)
			*why = NAME_ERR_LEADING_SLASH;
		return (-1);
	}

	/* Skip leading slash  */
	start = &path[1];
	do {
		end = start;
		while (*end != '/' && *end != '\0')
			end++;

		if (end - start >= MAXNAMELEN) {
			if (why)
				*why = NAME_ERR_TOOLONG;
			return (-1);
		}
		start = end + 1;

	} while (*end != '\0');

	return (0);
}

/*
 * For pool names, we have the same set of valid characters as described in
 * dataset names, with the additional restriction that the pool name must begin
 * with a letter.  The pool names 'raidz' and 'mirror' are also reserved names
 * that cannot be used.
 */
int
pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
{
	const char *c;

	/*
	 * Make sure the name is not too long.
	 *
	 * ZPOOL_MAXNAMELEN is the maximum pool length used in the userland
	 * which is the same as MAXNAMELEN used in the kernel.
	 * If ZPOOL_MAXNAMELEN value is changed, make sure to cleanup all
	 * places using MAXNAMELEN.
	 *
	 * When HAVE_KOBJ_NAME_LEN is defined the maximum safe kobject name
	 * length is 20 bytes.  This 20 bytes is broken down as follows to
	 * provide a maximum safe <pool>/<dataset>[@snapshot] length of only
	 * 18 bytes.  To ensure bytes are left for <dataset>[@snapshot] the
	 * <pool> portition is futher limited to 8 bytes.  For 2.6.27 and
	 * newer kernels this limit is set to MAXNAMELEN.
	 *
	 *   <pool>/<dataset> + <partition> + <newline>
	 *   (18)             + (1)         + (1)
	 */
#ifdef HAVE_KOBJ_NAME_LEN
	if (strlen(pool) > 8) {
#else
	if (strlen(pool) >= MAXNAMELEN) {
#endif /* HAVE_KOBJ_NAME_LEN */
		if (why)
			*why = NAME_ERR_TOOLONG;
		return (-1);
	}

	c = pool;
	while (*c != '\0') {
		if (!valid_char(*c)) {
			if (why) {
				*why = NAME_ERR_INVALCHAR;
				*what = *c;
			}
			return (-1);
		}
		c++;
	}

	if (!(*pool >= 'a' && *pool <= 'z') &&
	    !(*pool >= 'A' && *pool <= 'Z')) {
		if (why)
			*why = NAME_ERR_NOLETTER;
		return (-1);
	}

	if (strcmp(pool, "mirror") == 0 || strcmp(pool, "raidz") == 0) {
		if (why)
			*why = NAME_ERR_RESERVED;
		return (-1);
	}

	if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
		if (why)
			*why = NAME_ERR_DISKLIKE;
		return (-1);
	}

	return (0);
}

#if defined(_KERNEL) && defined(HAVE_SPL)
EXPORT_SYMBOL(snapshot_namecheck);
EXPORT_SYMBOL(pool_namecheck);
EXPORT_SYMBOL(dataset_namecheck);
#endif
Commit	Line	Data
34dc7c2f BB	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	/*
9babb374	22	* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
34dc7c2f BB	23	* Use is subject to license terms.
	24	*/
	25
34dc7c2f BB	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
	49	static int
	50	valid_char(char c)
	51	{
	52	return ((c >= 'a' && c <= 'z') \|\|
	53	(c >= 'A' && c <= 'Z') \|\|
	54	(c >= '0' && c <= '9') \|\|
b128c09f	55	c == '-' \|\| c == '_' \|\| c == '.' \|\| c == ':' \|\| c == ' ');
34dc7c2f BB	56	}
	57
	58	/*
	59	* Snapshot names must be made up of alphanumeric characters plus the following
	60	* characters:
	61	*
45d1cae3	62	* [-_.: ]
34dc7c2f BB	63	*/
	64	int
	65	snapshot_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	*/
	99	int
	100	permset_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	*/
132	int
133	dataset_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.
60101509 BB	145	*
	146	* When HAVE_KOBJ_NAME_LEN is defined the maximum safe kobject name
	147	* length is 20 bytes. This 20 bytes is broken down as follows to
	148	* provide a maximum safe <pool>/<dataset>[@snapshot] length of only
	149	* 18 bytes. To ensure bytes are left for <dataset>[@snapshot] the
	150	* <pool> portition is futher limited to 9 bytes. For 2.6.27 and
	151	* newer kernels this limit is set to MAXNAMELEN.
	152	*
	153	* <pool>/<dataset> + <partition> + <newline>
	154	* (18) + (1) + (1)
34dc7c2f	155	*/
60101509 BB	156	#ifdef HAVE_KOBJ_NAME_LEN
	157	if (strlen(path) > 18) {
	158	#else
34dc7c2f	159	if (strlen(path) >= MAXNAMELEN) {
60101509	160	#endif /* HAVE_KOBJ_NAME_LEN */
34dc7c2f BB	161	if (why)
	162	*why = NAME_ERR_TOOLONG;
	163	return (-1);
	164	}
	165
	166	/* Explicitly check for a leading slash. */
	167	if (path[0] == '/') {
	168	if (why)
	169	*why = NAME_ERR_LEADING_SLASH;
	170	return (-1);
	171	}
	172
	173	if (path[0] == '\0') {
	174	if (why)
	175	*why = NAME_ERR_EMPTY_COMPONENT;
	176	return (-1);
	177	}
	178
	179	loc = path;
	180	found_snapshot = 0;
	181	for (;;) {
	182	/* Find the end of this component */
	183	end = loc;
	184	while (end != '/' && end != '@' && *end != '\0')
	185	end++;
	186
	187	if (*end == '\0' && end[-1] == '/') {
	188	/* trailing slashes are not allowed */
	189	if (why)
	190	*why = NAME_ERR_TRAILING_SLASH;
	191	return (-1);
	192	}
	193
	194	/* Zero-length components are not allowed */
	195	if (loc == end) {
	196	if (why) {
	197	/*
	198	* Make sure this is really a zero-length
	199	* component and not a '@@'.
	200	*/
	201	if (*end == '@' && found_snapshot) {
	202	*why = NAME_ERR_MULTIPLE_AT;
	203	} else {
	204	*why = NAME_ERR_EMPTY_COMPONENT;
	205	}
	206	}
	207
	208	return (-1);
	209	}
	210
	211	/* Validate the contents of this component */
	212	while (loc != end) {
	213	if (!valid_char(loc) && loc != '%') {
	214	if (why) {
	215	*why = NAME_ERR_INVALCHAR;
	216	what = loc;
	217	}
	218	return (-1);
	219	}
	220	loc++;
	221	}
	222
	223	/* If we've reached the end of the string, we're OK */
	224	if (*end == '\0')
225	return (0);
226
227	if (*end == '@') {
228	/*
229	* If we've found an @ symbol, indicate that we're in
230	* the snapshot component, and report a second '@'
231	* character as an error.
232	*/
233	if (found_snapshot) {
234	if (why)
235	*why = NAME_ERR_MULTIPLE_AT;
236	return (-1);
237	}
238
239	found_snapshot = 1;
240	}
241
242	/*
243	* If there is a '/' in a snapshot name
244	* then report an error
245	*/
246	if (*end == '/' && found_snapshot) {
247	if (why)
248	*why = NAME_ERR_TRAILING_SLASH;
249	return (-1);
250	}
251
252	/* Update to the next component */
253	loc = end + 1;
254	}
255	}
256
257
258	/*
259	* mountpoint names must be of the following form:
260	*
261	* /[component][/]*[component][/]
262	*/
263	int
264	mountpoint_namecheck(const char path, namecheck_err_t why)
265	{
266	const char start, end;
267
268	/*
269	* Make sure none of the mountpoint component names are too long.
270	* If a component name is too long then the mkdir of the mountpoint
271	* will fail but then the mountpoint property will be set to a value
272	* that can never be mounted. Better to fail before setting the prop.
273	* Extra slashes are OK, they will be tossed by the mountpoint mkdir.
274	*/
275
276	if (path == NULL \|\| *path != '/') {
277	if (why)
278	*why = NAME_ERR_LEADING_SLASH;
279	return (-1);
280	}
281
282	/* Skip leading slash */
283	start = &path[1];
284	do {
285	end = start;
286	while (end != '/' && end != '\0')
287	end++;
288
289	if (end - start >= MAXNAMELEN) {
290	if (why)
291	*why = NAME_ERR_TOOLONG;
292	return (-1);
293	}
294	start = end + 1;
295
296	} while (*end != '\0');
297
298	return (0);
299	}
300
301	/*
302	* For pool names, we have the same set of valid characters as described in
303	* dataset names, with the additional restriction that the pool name must begin
304	* with a letter. The pool names 'raidz' and 'mirror' are also reserved names
305	* that cannot be used.
306	*/
307	int
308	pool_namecheck(const char pool, namecheck_err_t why, char *what)
309	{
310	const char *c;
311
312	/*
313	* Make sure the name is not too long.
314	*
315	* ZPOOL_MAXNAMELEN is the maximum pool length used in the userland
316	* which is the same as MAXNAMELEN used in the kernel.
317	* If ZPOOL_MAXNAMELEN value is changed, make sure to cleanup all
318	* places using MAXNAMELEN.
60101509 BB	319	*
	320	* When HAVE_KOBJ_NAME_LEN is defined the maximum safe kobject name
	321	* length is 20 bytes. This 20 bytes is broken down as follows to
	322	* provide a maximum safe <pool>/<dataset>[@snapshot] length of only
	323	* 18 bytes. To ensure bytes are left for <dataset>[@snapshot] the
	324	* <pool> portition is futher limited to 8 bytes. For 2.6.27 and
	325	* newer kernels this limit is set to MAXNAMELEN.
	326	*
	327	* <pool>/<dataset> + <partition> + <newline>
	328	* (18) + (1) + (1)
34dc7c2f	329	*/
60101509 BB	330	#ifdef HAVE_KOBJ_NAME_LEN
	331	if (strlen(pool) > 8) {
	332	#else
34dc7c2f	333	if (strlen(pool) >= MAXNAMELEN) {
60101509	334	#endif /* HAVE_KOBJ_NAME_LEN */
34dc7c2f BB	335	if (why)
	336	*why = NAME_ERR_TOOLONG;
	337	return (-1);
	338	}
	339
	340	c = pool;
	341	while (*c != '\0') {
	342	if (!valid_char(*c)) {
	343	if (why) {
	344	*why = NAME_ERR_INVALCHAR;
	345	what = c;
	346	}
	347	return (-1);
	348	}
	349	c++;
	350	}
	351
	352	if (!(pool >= 'a' && pool <= 'z') &&
	353	!(pool >= 'A' && pool <= 'Z')) {
	354	if (why)
	355	*why = NAME_ERR_NOLETTER;
	356	return (-1);
	357	}
	358
	359	if (strcmp(pool, "mirror") == 0 \|\| strcmp(pool, "raidz") == 0) {
	360	if (why)
	361	*why = NAME_ERR_RESERVED;
	362	return (-1);
	363	}
	364
	365	if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
	366	if (why)
	367	*why = NAME_ERR_DISKLIKE;
	368	return (-1);
	369	}
	370
	371	return (0);
	372	}
c28b2279 BB	373
	374	#if defined(_KERNEL) && defined(HAVE_SPL)
	375	EXPORT_SYMBOL(snapshot_namecheck);
	376	EXPORT_SYMBOL(pool_namecheck);
	377	EXPORT_SYMBOL(dataset_namecheck);
	378	#endif