[deliverable/linux.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 *unused,
		struct inode *inode, const char *name, void *value, size_t size)
{
	int xflags = handler->flags;
	struct xfs_inode *ip = XFS_I(inode);
	int error, asize = size;

	/* 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 *unused,
		struct inode *inode, const char *name, const void *value,
		size_t size, int flags)
{
	int			xflags = handler->flags;
	struct xfs_inode	*ip = XFS_I(inode);
	int			error;

	/* 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(inode, 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 int
__xfs_xattr_put_listent(
	struct xfs_attr_list_context *context,
	char *prefix,
	int prefix_len,
	unsigned char *name,
	int namelen)
{
	char *offset;
	int arraytop;

	if (!context->alist)
		goto compute_size;

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

compute_size:
	context->count += prefix_len + namelen + 1;
	return 0;
}

static int
xfs_xattr_put_listent(
	struct xfs_attr_list_context *context,
	int		flags,
	unsigned char	*name,
	int		namelen,
	int		valuelen)
{
	char *prefix;
	int prefix_len;

	ASSERT(context->count >= 0);

	if (flags & XFS_ATTR_ROOT) {
#ifdef CONFIG_XFS_POSIX_ACL
		if (namelen == SGI_ACL_FILE_SIZE &&
		    strncmp(name, SGI_ACL_FILE,
			    SGI_ACL_FILE_SIZE) == 0) {
			int ret = __xfs_xattr_put_listent(
					context, XATTR_SYSTEM_PREFIX,
					XATTR_SYSTEM_PREFIX_LEN,
					XATTR_POSIX_ACL_ACCESS,
					strlen(XATTR_POSIX_ACL_ACCESS));
			if (ret)
				return ret;
		} else if (namelen == SGI_ACL_DEFAULT_SIZE &&
			 strncmp(name, SGI_ACL_DEFAULT,
				 SGI_ACL_DEFAULT_SIZE) == 0) {
			int ret = __xfs_xattr_put_listent(
					context, XATTR_SYSTEM_PREFIX,
					XATTR_SYSTEM_PREFIX_LEN,
					XATTR_POSIX_ACL_DEFAULT,
					strlen(XATTR_POSIX_ACL_DEFAULT));
			if (ret)
				return ret;
		}
#endif

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

		prefix = XATTR_TRUSTED_PREFIX;
		prefix_len = XATTR_TRUSTED_PREFIX_LEN;
	} else if (flags & XFS_ATTR_SECURE) {
		prefix = XATTR_SECURITY_PREFIX;
		prefix_len = XATTR_SECURITY_PREFIX_LEN;
	} else {
		prefix = XATTR_USER_PREFIX;
		prefix_len = XATTR_USER_PREFIX_LEN;
	}

	return __xfs_xattr_put_listent(context, prefix, prefix_len, name,
				       namelen);
}

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 = size ? data : NULL;
	context.bufsize = size;
	context.firstu = context.bufsize;
	context.put_listent = xfs_xattr_put_listent;

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

	return context.count;
}
Commit	Line	Data
	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"
	20	#include "xfs_format.h"
	21	#include "xfs_log_format.h"
	22	#include "xfs_trans_resv.h"
	23	#include "xfs_mount.h"
	24	#include "xfs_da_format.h"
	25	#include "xfs_inode.h"
	26	#include "xfs_attr.h"
	27	#include "xfs_attr_leaf.h"
	28	#include "xfs_acl.h"
	29
	30	#include <linux/posix_acl_xattr.h>
	31	#include <linux/xattr.h>
	32
	33
	34	static int
	35	xfs_xattr_get(const struct xattr_handler handler, struct dentry unused,
	36	struct inode inode, const char name, void *value, size_t size)
	37	{
	38	int xflags = handler->flags;
	39	struct xfs_inode *ip = XFS_I(inode);
	40	int error, asize = size;
	41
	42	/* Convert Linux syscall to XFS internal ATTR flags */
	43	if (!size) {
	44	xflags \|= ATTR_KERNOVAL;
	45	value = NULL;
	46	}
	47
	48	error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags);
	49	if (error)
	50	return error;
	51	return asize;
	52	}
	53
	54	void
	55	xfs_forget_acl(
	56	struct inode *inode,
	57	const char *name,
	58	int xflags)
	59	{
	60	/*
	61	* Invalidate any cached ACLs if the user has bypassed the ACL
	62	* interface. We don't validate the content whatsoever so it is caller
	63	* responsibility to provide data in valid format and ensure i_mode is
	64	* consistent.
	65	*/
	66	if (xflags & ATTR_ROOT) {
	67	#ifdef CONFIG_XFS_POSIX_ACL
	68	if (!strcmp(name, SGI_ACL_FILE))
	69	forget_cached_acl(inode, ACL_TYPE_ACCESS);
	70	else if (!strcmp(name, SGI_ACL_DEFAULT))
	71	forget_cached_acl(inode, ACL_TYPE_DEFAULT);
	72	#endif
	73	}
	74	}
	75
	76	static int
	77	xfs_xattr_set(const struct xattr_handler handler, struct dentry unused,
	78	struct inode inode, const char name, const void *value,
	79	size_t size, int flags)
	80	{
	81	int xflags = handler->flags;
	82	struct xfs_inode *ip = XFS_I(inode);
	83	int error;
	84
	85	/* Convert Linux syscall to XFS internal ATTR flags */
	86	if (flags & XATTR_CREATE)
	87	xflags \|= ATTR_CREATE;
	88	if (flags & XATTR_REPLACE)
	89	xflags \|= ATTR_REPLACE;
	90
	91	if (!value)
	92	return xfs_attr_remove(ip, (unsigned char *)name, xflags);
	93	error = xfs_attr_set(ip, (unsigned char *)name,
	94	(void *)value, size, xflags);
	95	if (!error)
	96	xfs_forget_acl(inode, name, xflags);
	97
	98	return error;
	99	}
	100
	101	static const struct xattr_handler xfs_xattr_user_handler = {
	102	.prefix = XATTR_USER_PREFIX,
	103	.flags = 0, /* no flags implies user namespace */
	104	.get = xfs_xattr_get,
	105	.set = xfs_xattr_set,
	106	};
	107
	108	static const struct xattr_handler xfs_xattr_trusted_handler = {
	109	.prefix = XATTR_TRUSTED_PREFIX,
	110	.flags = ATTR_ROOT,
	111	.get = xfs_xattr_get,
	112	.set = xfs_xattr_set,
	113	};
	114
	115	static const struct xattr_handler xfs_xattr_security_handler = {
	116	.prefix = XATTR_SECURITY_PREFIX,
	117	.flags = ATTR_SECURE,
	118	.get = xfs_xattr_get,
	119	.set = xfs_xattr_set,
	120	};
	121
	122	const struct xattr_handler *xfs_xattr_handlers[] = {
	123	&xfs_xattr_user_handler,
	124	&xfs_xattr_trusted_handler,
	125	&xfs_xattr_security_handler,
	126	#ifdef CONFIG_XFS_POSIX_ACL
	127	&posix_acl_access_xattr_handler,
	128	&posix_acl_default_xattr_handler,
	129	#endif
	130	NULL
	131	};
	132
	133	static int
	134	__xfs_xattr_put_listent(
	135	struct xfs_attr_list_context *context,
	136	char *prefix,
	137	int prefix_len,
	138	unsigned char *name,
	139	int namelen)
	140	{
	141	char *offset;
	142	int arraytop;
	143
	144	if (!context->alist)
	145	goto compute_size;
	146
	147	arraytop = context->count + prefix_len + namelen + 1;
	148	if (arraytop > context->firstu) {
	149	context->count = -1; /* insufficient space */
	150	return 0;
	151	}
	152	offset = (char *)context->alist + context->count;
	153	strncpy(offset, prefix, prefix_len);
	154	offset += prefix_len;
	155	strncpy(offset, (char )name, namelen); / real name */
	156	offset += namelen;
	157	*offset = '\0';
	158
	159	compute_size:
	160	context->count += prefix_len + namelen + 1;
	161	return 0;
	162	}
	163
	164	static int
	165	xfs_xattr_put_listent(
	166	struct xfs_attr_list_context *context,
	167	int flags,
	168	unsigned char *name,
	169	int namelen,
	170	int valuelen)
	171	{
	172	char *prefix;
	173	int prefix_len;
	174
	175	ASSERT(context->count >= 0);
	176
	177	if (flags & XFS_ATTR_ROOT) {
	178	#ifdef CONFIG_XFS_POSIX_ACL
	179	if (namelen == SGI_ACL_FILE_SIZE &&
	180	strncmp(name, SGI_ACL_FILE,
	181	SGI_ACL_FILE_SIZE) == 0) {
	182	int ret = __xfs_xattr_put_listent(
	183	context, XATTR_SYSTEM_PREFIX,
	184	XATTR_SYSTEM_PREFIX_LEN,
	185	XATTR_POSIX_ACL_ACCESS,
	186	strlen(XATTR_POSIX_ACL_ACCESS));
	187	if (ret)
	188	return ret;
	189	} else if (namelen == SGI_ACL_DEFAULT_SIZE &&
	190	strncmp(name, SGI_ACL_DEFAULT,
	191	SGI_ACL_DEFAULT_SIZE) == 0) {
	192	int ret = __xfs_xattr_put_listent(
	193	context, XATTR_SYSTEM_PREFIX,
	194	XATTR_SYSTEM_PREFIX_LEN,
	195	XATTR_POSIX_ACL_DEFAULT,
	196	strlen(XATTR_POSIX_ACL_DEFAULT));
	197	if (ret)
	198	return ret;
	199	}
	200	#endif
	201
	202	/*
	203	* Only show root namespace entries if we are actually allowed to
	204	* see them.
	205	*/
	206	if (!capable(CAP_SYS_ADMIN))
	207	return 0;
	208
	209	prefix = XATTR_TRUSTED_PREFIX;
	210	prefix_len = XATTR_TRUSTED_PREFIX_LEN;
	211	} else if (flags & XFS_ATTR_SECURE) {
	212	prefix = XATTR_SECURITY_PREFIX;
	213	prefix_len = XATTR_SECURITY_PREFIX_LEN;
	214	} else {
	215	prefix = XATTR_USER_PREFIX;
	216	prefix_len = XATTR_USER_PREFIX_LEN;
	217	}
	218
	219	return __xfs_xattr_put_listent(context, prefix, prefix_len, name,
	220	namelen);
	221	}
	222
	223	ssize_t
	224	xfs_vn_listxattr(
	225	struct dentry *dentry,
	226	char *data,
	227	size_t size)
	228	{
	229	struct xfs_attr_list_context context;
	230	struct attrlist_cursor_kern cursor = { 0 };
	231	struct inode *inode = d_inode(dentry);
	232	int error;
	233
	234	/*
	235	* First read the regular on-disk attributes.
	236	*/
	237	memset(&context, 0, sizeof(context));
	238	context.dp = XFS_I(inode);
	239	context.cursor = &cursor;
	240	context.resynch = 1;
	241	context.alist = size ? data : NULL;
	242	context.bufsize = size;
	243	context.firstu = context.bufsize;
	244	context.put_listent = xfs_xattr_put_listent;
	245
	246	error = xfs_attr_list_int(&context);
	247	if (error)
	248	return error;
	249	if (context.count < 0)
	250	return -ERANGE;
	251
	252	return context.count;
	253	}