[mirror_ubuntu-zesty-kernel.git] / fs / xfs / xfs_xattr.c

/*
 * Copyright (C) 2008 Christoph Hellwig.
 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "xfs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_inode.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_acl.h"

#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>


static int
xfs_xattr_get(const struct xattr_handler *handler, struct dentry *dentry,
		const char *name, void *value, size_t size)
{
	int xflags = handler->flags;
	struct xfs_inode *ip = XFS_I(d_inode(dentry));
	int error, asize = size;

	if (strcmp(name, "") == 0)
		return -EINVAL;

	/* Convert Linux syscall to XFS internal ATTR flags */
	if (!size) {
		xflags |= ATTR_KERNOVAL;
		value = NULL;
	}

	error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
	if (error)
		return error;
	return asize;
}

void
xfs_forget_acl(
	struct inode		*inode,
	const char		*name,
	int			xflags)
{
	/*
	 * Invalidate any cached ACLs if the user has bypassed the ACL
	 * interface. We don't validate the content whatsoever so it is caller
	 * responsibility to provide data in valid format and ensure i_mode is
	 * consistent.
	 */
	if (xflags & ATTR_ROOT) {
#ifdef CONFIG_XFS_POSIX_ACL
		if (!strcmp(name, SGI_ACL_FILE))
			forget_cached_acl(inode, ACL_TYPE_ACCESS);
		else if (!strcmp(name, SGI_ACL_DEFAULT))
			forget_cached_acl(inode, ACL_TYPE_DEFAULT);
#endif
	}
}

static int
xfs_xattr_set(const struct xattr_handler *handler, struct dentry *dentry,
		const char *name, const void *value, size_t size, int flags)
{
	int			xflags = handler->flags;
	struct xfs_inode	*ip = XFS_I(d_inode(dentry));
	int			error;

	if (strcmp(name, "") == 0)
		return -EINVAL;

	/* Convert Linux syscall to XFS internal ATTR flags */
	if (flags & XATTR_CREATE)
		xflags |= ATTR_CREATE;
	if (flags & XATTR_REPLACE)
		xflags |= ATTR_REPLACE;

	if (!value)
		return xfs_attr_remove(ip, (unsigned char *)name, xflags);
	error = xfs_attr_set(ip, (unsigned char *)name,
				(void *)value, size, xflags);
	if (!error)
		xfs_forget_acl(d_inode(dentry), name, xflags);

	return error;
}

static const struct xattr_handler xfs_xattr_user_handler = {
	.prefix	= XATTR_USER_PREFIX,
	.flags	= 0, /* no flags implies user namespace */
	.get	= xfs_xattr_get,
	.set	= xfs_xattr_set,
};

static const struct xattr_handler xfs_xattr_trusted_handler = {
	.prefix	= XATTR_TRUSTED_PREFIX,
	.flags	= ATTR_ROOT,
	.get	= xfs_xattr_get,
	.set	= xfs_xattr_set,
};

static const struct xattr_handler xfs_xattr_security_handler = {
	.prefix	= XATTR_SECURITY_PREFIX,
	.flags	= ATTR_SECURE,
	.get	= xfs_xattr_get,
	.set	= xfs_xattr_set,
};

const struct xattr_handler *xfs_xattr_handlers[] = {
	&xfs_xattr_user_handler,
	&xfs_xattr_trusted_handler,
	&xfs_xattr_security_handler,
#ifdef CONFIG_XFS_POSIX_ACL
	&posix_acl_access_xattr_handler,
	&posix_acl_default_xattr_handler,
#endif
	NULL
};

static unsigned int xfs_xattr_prefix_len(int flags)
{
	if (flags & XFS_ATTR_SECURE)
		return sizeof("security");
	else if (flags & XFS_ATTR_ROOT)
		return sizeof("trusted");
	else
		return sizeof("user");
}

static const char *xfs_xattr_prefix(int flags)
{
	if (flags & XFS_ATTR_SECURE)
		return xfs_xattr_security_handler.prefix;
	else if (flags & XFS_ATTR_ROOT)
		return xfs_xattr_trusted_handler.prefix;
	else
		return xfs_xattr_user_handler.prefix;
}

static int
xfs_xattr_put_listent(
	struct xfs_attr_list_context *context,
	int		flags,
	unsigned char	*name,
	int		namelen,
	int		valuelen,
	unsigned char	*value)
{
	unsigned int prefix_len = xfs_xattr_prefix_len(flags);
	char *offset;
	int arraytop;

	ASSERT(context->count >= 0);

	/*
	 * Only show root namespace entries if we are actually allowed to
	 * see them.
	 */
	if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN))
		return 0;

	arraytop = context->count + prefix_len + namelen + 1;
	if (arraytop > context->firstu) {
		context->count = -1;	/* insufficient space */
		return 1;
	}
	offset = (char *)context->alist + context->count;
	strncpy(offset, xfs_xattr_prefix(flags), prefix_len);
	offset += prefix_len;
	strncpy(offset, (char *)name, namelen);			/* real name */
	offset += namelen;
	*offset = '\0';
	context->count += prefix_len + namelen + 1;
	return 0;
}

static int
xfs_xattr_put_listent_sizes(
	struct xfs_attr_list_context *context,
	int		flags,
	unsigned char	*name,
	int		namelen,
	int		valuelen,
	unsigned char	*value)
{
	context->count += xfs_xattr_prefix_len(flags) + namelen + 1;
	return 0;
}

static int
list_one_attr(const char *name, const size_t len, void *data,
		size_t size, ssize_t *result)
{
	char *p = data + *result;

	*result += len;
	if (!size)
		return 0;
	if (*result > size)
		return -ERANGE;

	strcpy(p, name);
	return 0;
}

ssize_t
xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)
{
	struct xfs_attr_list_context context;
	struct attrlist_cursor_kern cursor = { 0 };
	struct inode		*inode = d_inode(dentry);
	int			error;

	/*
	 * First read the regular on-disk attributes.
	 */
	memset(&context, 0, sizeof(context));
	context.dp = XFS_I(inode);
	context.cursor = &cursor;
	context.resynch = 1;
	context.alist = data;
	context.bufsize = size;
	context.firstu = context.bufsize;

	if (size)
		context.put_listent = xfs_xattr_put_listent;
	else
		context.put_listent = xfs_xattr_put_listent_sizes;

	xfs_attr_list_int(&context);
	if (context.count < 0)
		return -ERANGE;

	/*
	 * Then add the two synthetic ACL attributes.
	 */
	if (posix_acl_access_exists(inode)) {
		error = list_one_attr(XATTR_NAME_POSIX_ACL_ACCESS,
				strlen(XATTR_NAME_POSIX_ACL_ACCESS) + 1,
				data, size, &context.count);
		if (error)
			return error;
	}

	if (posix_acl_default_exists(inode)) {
		error = list_one_attr(XATTR_NAME_POSIX_ACL_DEFAULT,
				strlen(XATTR_NAME_POSIX_ACL_DEFAULT) + 1,
				data, size, &context.count);
		if (error)
			return error;
	}

	return context.count;
}
Commit	Line	Data
f9e09f09 LM	1	/*
	2	* Copyright (C) 2008 Christoph Hellwig.
	3	* Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	17	*/
	18
	19	#include "xfs.h"
a4fbe6ab	20	#include "xfs_format.h"
69432832	21	#include "xfs_log_format.h"
239880ef	22	#include "xfs_trans_resv.h"
57062787 DC	23	#include "xfs_mount.h"
57062787 DC	24	#include "xfs_da_format.h"
f9e09f09 LM	25	#include "xfs_inode.h"
	26	#include "xfs_attr.h"
	27	#include "xfs_attr_leaf.h"
	28	#include "xfs_acl.h"
f9e09f09 LM	29
	30	#include <linux/posix_acl_xattr.h>
	31	#include <linux/xattr.h>
	32
	33
f9e09f09	34	static int
d9a82a04 AG	35	xfs_xattr_get(const struct xattr_handler handler, struct dentry dentry,
d9a82a04 AG	36	const char name, void value, size_t size)
f9e09f09	37	{
d9a82a04	38	int xflags = handler->flags;
2b0143b5	39	struct xfs_inode *ip = XFS_I(d_inode(dentry));
f9e09f09 LM	40	int error, asize = size;
	41
	42	if (strcmp(name, "") == 0)
	43	return -EINVAL;
	44
	45	/* Convert Linux syscall to XFS internal ATTR flags */
	46	if (!size) {
	47	xflags \|= ATTR_KERNOVAL;
	48	value = NULL;
	49	}
	50
2451337d	51	error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
f9e09f09 LM	52	if (error)
	53	return error;
	54	return asize;
	55	}
	56
47e1bf64 AG	57	void
	58	xfs_forget_acl(
	59	struct inode *inode,
	60	const char *name,
	61	int xflags)
	62	{
	63	/*
	64	* Invalidate any cached ACLs if the user has bypassed the ACL
	65	* interface. We don't validate the content whatsoever so it is caller
	66	* responsibility to provide data in valid format and ensure i_mode is
	67	* consistent.
	68	*/
	69	if (xflags & ATTR_ROOT) {
	70	#ifdef CONFIG_XFS_POSIX_ACL
	71	if (!strcmp(name, SGI_ACL_FILE))
	72	forget_cached_acl(inode, ACL_TYPE_ACCESS);
	73	else if (!strcmp(name, SGI_ACL_DEFAULT))
	74	forget_cached_acl(inode, ACL_TYPE_DEFAULT);
	75	#endif
	76	}
	77	}
	78
f9e09f09	79	static int
d9a82a04 AG	80	xfs_xattr_set(const struct xattr_handler handler, struct dentry dentry,
d9a82a04 AG	81	const char name, const void value, size_t size, int flags)
f9e09f09	82	{
5d2eb548	83	int xflags = handler->flags;
67d8e04e BF	84	struct xfs_inode *ip = XFS_I(d_inode(dentry));
67d8e04e BF	85	int error;
f9e09f09 LM	86
	87	if (strcmp(name, "") == 0)
	88	return -EINVAL;
	89
	90	/* Convert Linux syscall to XFS internal ATTR flags */
	91	if (flags & XATTR_CREATE)
	92	xflags \|= ATTR_CREATE;
	93	if (flags & XATTR_REPLACE)
	94	xflags \|= ATTR_REPLACE;
	95
	96	if (!value)
2451337d	97	return xfs_attr_remove(ip, (unsigned char *)name, xflags);
67d8e04e	98	error = xfs_attr_set(ip, (unsigned char *)name,
a9273ca5	99	(void *)value, size, xflags);
47e1bf64 AG	100	if (!error)
47e1bf64 AG	101	xfs_forget_acl(d_inode(dentry), name, xflags);
67d8e04e BF	102
67d8e04e BF	103	return error;
f9e09f09 LM	104	}
f9e09f09 LM	105
46e58764	106	static const struct xattr_handler xfs_xattr_user_handler = {
f9e09f09	107	.prefix = XATTR_USER_PREFIX,
431547b3 CH	108	.flags = 0, /* no flags implies user namespace */
	109	.get = xfs_xattr_get,
	110	.set = xfs_xattr_set,
f9e09f09 LM	111	};
f9e09f09 LM	112
46e58764	113	static const struct xattr_handler xfs_xattr_trusted_handler = {
f9e09f09	114	.prefix = XATTR_TRUSTED_PREFIX,
431547b3 CH	115	.flags = ATTR_ROOT,
	116	.get = xfs_xattr_get,
	117	.set = xfs_xattr_set,
f9e09f09 LM	118	};
f9e09f09 LM	119
46e58764	120	static const struct xattr_handler xfs_xattr_security_handler = {
f9e09f09	121	.prefix = XATTR_SECURITY_PREFIX,
431547b3 CH	122	.flags = ATTR_SECURE,
	123	.get = xfs_xattr_get,
	124	.set = xfs_xattr_set,
f9e09f09 LM	125	};
f9e09f09 LM	126
46e58764	127	const struct xattr_handler *xfs_xattr_handlers[] = {
f9e09f09 LM	128	&xfs_xattr_user_handler,
	129	&xfs_xattr_trusted_handler,
	130	&xfs_xattr_security_handler,
ef14f0c1	131	#ifdef CONFIG_XFS_POSIX_ACL
2401dc29 CH	132	&posix_acl_access_xattr_handler,
2401dc29 CH	133	&posix_acl_default_xattr_handler,
ef14f0c1	134	#endif
f9e09f09 LM	135	NULL
	136	};
	137
	138	static unsigned int xfs_xattr_prefix_len(int flags)
	139	{
	140	if (flags & XFS_ATTR_SECURE)
	141	return sizeof("security");
	142	else if (flags & XFS_ATTR_ROOT)
	143	return sizeof("trusted");
	144	else
	145	return sizeof("user");
	146	}
	147
	148	static const char *xfs_xattr_prefix(int flags)
	149	{
	150	if (flags & XFS_ATTR_SECURE)
	151	return xfs_xattr_security_handler.prefix;
	152	else if (flags & XFS_ATTR_ROOT)
	153	return xfs_xattr_trusted_handler.prefix;
	154	else
	155	return xfs_xattr_user_handler.prefix;
	156	}
	157
	158	static int
a9273ca5 DC	159	xfs_xattr_put_listent(
	160	struct xfs_attr_list_context *context,
	161	int flags,
	162	unsigned char *name,
	163	int namelen,
	164	int valuelen,
	165	unsigned char *value)
f9e09f09 LM	166	{
	167	unsigned int prefix_len = xfs_xattr_prefix_len(flags);
	168	char *offset;
	169	int arraytop;
	170
	171	ASSERT(context->count >= 0);
	172
	173	/*
	174	* Only show root namespace entries if we are actually allowed to
	175	* see them.
	176	*/
	177	if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN))
	178	return 0;
	179
	180	arraytop = context->count + prefix_len + namelen + 1;
	181	if (arraytop > context->firstu) {
	182	context->count = -1; /* insufficient space */
	183	return 1;
	184	}
	185	offset = (char *)context->alist + context->count;
	186	strncpy(offset, xfs_xattr_prefix(flags), prefix_len);
	187	offset += prefix_len;
a9273ca5	188	strncpy(offset, (char )name, namelen); / real name */
f9e09f09 LM	189	offset += namelen;
	190	*offset = '\0';
	191	context->count += prefix_len + namelen + 1;
	192	return 0;
	193	}
	194
	195	static int
a9273ca5 DC	196	xfs_xattr_put_listent_sizes(
	197	struct xfs_attr_list_context *context,
	198	int flags,
	199	unsigned char *name,
	200	int namelen,
	201	int valuelen,
	202	unsigned char *value)
f9e09f09 LM	203	{
	204	context->count += xfs_xattr_prefix_len(flags) + namelen + 1;
	205	return 0;
	206	}
	207
	208	static int
	209	list_one_attr(const char name, const size_t len, void data,
	210	size_t size, ssize_t *result)
	211	{
	212	char p = data + result;
	213
	214	*result += len;
	215	if (!size)
	216	return 0;
	217	if (*result > size)
	218	return -ERANGE;
	219
	220	strcpy(p, name);
	221	return 0;
	222	}
	223
	224	ssize_t
	225	xfs_vn_listxattr(struct dentry dentry, char data, size_t size)
	226	{
	227	struct xfs_attr_list_context context;
	228	struct attrlist_cursor_kern cursor = { 0 };
2b0143b5	229	struct inode *inode = d_inode(dentry);
f9e09f09 LM	230	int error;
	231
	232	/*
	233	* First read the regular on-disk attributes.
	234	*/
	235	memset(&context, 0, sizeof(context));
	236	context.dp = XFS_I(inode);
	237	context.cursor = &cursor;
	238	context.resynch = 1;
	239	context.alist = data;
	240	context.bufsize = size;
	241	context.firstu = context.bufsize;
	242
	243	if (size)
	244	context.put_listent = xfs_xattr_put_listent;
	245	else
	246	context.put_listent = xfs_xattr_put_listent_sizes;
	247
	248	xfs_attr_list_int(&context);
	249	if (context.count < 0)
	250	return -ERANGE;
	251
	252	/*
	253	* Then add the two synthetic ACL attributes.
	254	*/
ef14f0c1	255	if (posix_acl_access_exists(inode)) {
97d79299 AG	256	error = list_one_attr(XATTR_NAME_POSIX_ACL_ACCESS,
97d79299 AG	257	strlen(XATTR_NAME_POSIX_ACL_ACCESS) + 1,
f9e09f09 LM	258	data, size, &context.count);
	259	if (error)
	260	return error;
	261	}
	262
ef14f0c1	263	if (posix_acl_default_exists(inode)) {
97d79299 AG	264	error = list_one_attr(XATTR_NAME_POSIX_ACL_DEFAULT,
97d79299 AG	265	strlen(XATTR_NAME_POSIX_ACL_DEFAULT) + 1,
f9e09f09 LM	266	data, size, &context.count);
	267	if (error)
	268	return error;
	269	}
	270
	271	return context.count;
	272	}