/*
* 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_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_acl.h"
#include "xfs_vnodeops.h"
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
/*
* ACL handling. Should eventually be moved into xfs_acl.c
*/
static int
xfs_decode_acl(const char *name)
{
if (strcmp(name, "posix_acl_access") == 0)
return _ACL_TYPE_ACCESS;
else if (strcmp(name, "posix_acl_default") == 0)
return _ACL_TYPE_DEFAULT;
return -EINVAL;
}
/*
* Get system extended attributes which at the moment only
* includes Posix ACLs.
*/
static int
xfs_xattr_system_get(struct inode *inode, const char *name,
void *buffer, size_t size)
{
int acl;
acl = xfs_decode_acl(name);
if (acl < 0)
return acl;
return xfs_acl_vget(inode, buffer, size, acl);
}
static int
xfs_xattr_system_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
int acl;
acl = xfs_decode_acl(name);
if (acl < 0)
return acl;
if (flags & XATTR_CREATE)
return -EINVAL;
if (!value)
return xfs_acl_vremove(inode, acl);
return xfs_acl_vset(inode, (void *)value, size, acl);
}
static struct xattr_handler xfs_xattr_system_handler = {
.prefix = XATTR_SYSTEM_PREFIX,
.get = xfs_xattr_system_get,
.set = xfs_xattr_system_set,
};
/*
* Real xattr handling. The only difference between the namespaces is
* a flag passed to the low-level attr code.
*/
static int
__xfs_xattr_get(struct inode *inode, const char *name,
void *value, size_t size, int xflags)
{
struct xfs_inode *ip = XFS_I(inode);
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, name, value, &asize, xflags);
if (error)
return error;
return asize;
}
static int
__xfs_xattr_set(struct inode *inode, const char *name, const void *value,
size_t size, int flags, int xflags)
{
struct xfs_inode *ip = XFS_I(inode);
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, name, xflags);
return -xfs_attr_set(ip, name, (void *)value, size, xflags);
}
static int
xfs_xattr_user_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, 0);
}
static int
xfs_xattr_user_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, 0);
}
static struct xattr_handler xfs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.get = xfs_xattr_user_get,
.set = xfs_xattr_user_set,
};
static int
xfs_xattr_trusted_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT);
}
static int
xfs_xattr_trusted_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT);
}
static struct xattr_handler xfs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.get = xfs_xattr_trusted_get,
.set = xfs_xattr_trusted_set,
};
static int
xfs_xattr_secure_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE);
}
static int
xfs_xattr_secure_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE);
}
static struct xattr_handler xfs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.get = xfs_xattr_secure_get,
.set = xfs_xattr_secure_set,
};
struct xattr_handler *xfs_xattr_handlers[] = {
&xfs_xattr_user_handler,
&xfs_xattr_trusted_handler,
&xfs_xattr_security_handler,
&xfs_xattr_system_handler,
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,
char *name, int namelen, int valuelen, 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, 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,
char *name, int namelen, int valuelen, 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 = dentry->d_inode;
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 (xfs_acl_vhasacl_access(inode)) {
error = list_one_attr(POSIX_ACL_XATTR_ACCESS,
strlen(POSIX_ACL_XATTR_ACCESS) + 1,
data, size, &context.count);
if (error)
return error;
}
if (xfs_acl_vhasacl_default(inode)) {
error = list_one_attr(POSIX_ACL_XATTR_DEFAULT,
strlen(POSIX_ACL_XATTR_DEFAULT) + 1,
data, size, &context.count);
if (error)
return error;
}
return context.count;
}
