linux/fs/cifs/xattr.c

333 lines
8.3 KiB
C

/*
* fs/cifs/xattr.c
*
* Copyright (c) International Business Machines Corp., 2003, 2007
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/posix_acl_xattr.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#define MAX_EA_VALUE_SIZE 65535
#define CIFS_XATTR_CIFS_ACL "system.cifs_acl"
/* BB need to add server (Samba e.g) support for security and trusted prefix */
enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT };
static int cifs_xattr_set(const struct xattr_handler *handler,
struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
int rc = -EOPNOTSUPP;
unsigned int xid;
struct super_block *sb = dentry->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
char *full_path;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
full_path = build_path_from_dentry(dentry);
if (full_path == NULL) {
rc = -ENOMEM;
goto out;
}
/* return dos attributes as pseudo xattr */
/* return alt name if available as pseudo attr */
/* if proc/fs/cifs/streamstoxattr is set then
search server for EAs or streams to
returns as xattrs */
if (size > MAX_EA_VALUE_SIZE) {
cifs_dbg(FYI, "size of EA value too large\n");
rc = -EOPNOTSUPP;
goto out;
}
switch (handler->flags) {
case XATTR_USER:
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto out;
if (pTcon->ses->server->ops->set_EA)
rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
full_path, name, value, (__u16)size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
break;
case XATTR_CIFS_ACL: {
#ifdef CONFIG_CIFS_ACL
struct cifs_ntsd *pacl;
if (!value)
goto out;
pacl = kmalloc(size, GFP_KERNEL);
if (!pacl) {
rc = -ENOMEM;
} else {
memcpy(pacl, value, size);
if (value &&
pTcon->ses->server->ops->set_acl)
rc = pTcon->ses->server->ops->set_acl(pacl,
size, d_inode(dentry),
full_path, CIFS_ACL_DACL);
else
rc = -EOPNOTSUPP;
if (rc == 0) /* force revalidate of the inode */
CIFS_I(d_inode(dentry))->time = 0;
kfree(pacl);
}
#endif /* CONFIG_CIFS_ACL */
break;
}
case XATTR_ACL_ACCESS:
#ifdef CONFIG_CIFS_POSIX
if (!value)
goto out;
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
value, (const int)size,
ACL_TYPE_ACCESS, cifs_sb->local_nls,
cifs_remap(cifs_sb));
#endif /* CONFIG_CIFS_POSIX */
break;
case XATTR_ACL_DEFAULT:
#ifdef CONFIG_CIFS_POSIX
if (!value)
goto out;
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
value, (const int)size,
ACL_TYPE_DEFAULT, cifs_sb->local_nls,
cifs_remap(cifs_sb));
#endif /* CONFIG_CIFS_POSIX */
break;
}
out:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
return rc;
}
static int cifs_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *value, size_t size)
{
ssize_t rc = -EOPNOTSUPP;
unsigned int xid;
struct super_block *sb = dentry->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
char *full_path;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
full_path = build_path_from_dentry(dentry);
if (full_path == NULL) {
rc = -ENOMEM;
goto out;
}
/* return dos attributes as pseudo xattr */
/* return alt name if available as pseudo attr */
switch (handler->flags) {
case XATTR_USER:
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto out;
if (pTcon->ses->server->ops->query_all_EAs)
rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
full_path, name, value, size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
break;
case XATTR_CIFS_ACL: {
#ifdef CONFIG_CIFS_ACL
u32 acllen;
struct cifs_ntsd *pacl;
if (pTcon->ses->server->ops->get_acl == NULL)
goto out; /* rc already EOPNOTSUPP */
pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
inode, full_path, &acllen);
if (IS_ERR(pacl)) {
rc = PTR_ERR(pacl);
cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
__func__, rc);
} else {
if (value) {
if (acllen > size)
acllen = -ERANGE;
else
memcpy(value, pacl, acllen);
}
rc = acllen;
kfree(pacl);
}
#endif /* CONFIG_CIFS_ACL */
break;
}
case XATTR_ACL_ACCESS:
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
value, size, ACL_TYPE_ACCESS,
cifs_sb->local_nls,
cifs_remap(cifs_sb));
#endif /* CONFIG_CIFS_POSIX */
break;
case XATTR_ACL_DEFAULT:
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
value, size, ACL_TYPE_DEFAULT,
cifs_sb->local_nls,
cifs_remap(cifs_sb));
#endif /* CONFIG_CIFS_POSIX */
break;
}
/* We could add an additional check for streams ie
if proc/fs/cifs/streamstoxattr is set then
search server for EAs or streams to
returns as xattrs */
if (rc == -EINVAL)
rc = -EOPNOTSUPP;
out:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
return rc;
}
ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
{
ssize_t rc = -EOPNOTSUPP;
unsigned int xid;
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
char *full_path;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
return -EOPNOTSUPP;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
full_path = build_path_from_dentry(direntry);
if (full_path == NULL) {
rc = -ENOMEM;
goto list_ea_exit;
}
/* return dos attributes as pseudo xattr */
/* return alt name if available as pseudo attr */
/* if proc/fs/cifs/streamstoxattr is set then
search server for EAs or streams to
returns as xattrs */
if (pTcon->ses->server->ops->query_all_EAs)
rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
full_path, NULL, data, buf_size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
list_ea_exit:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
return rc;
}
static const struct xattr_handler cifs_user_xattr_handler = {
.prefix = XATTR_USER_PREFIX,
.flags = XATTR_USER,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
/* os2.* attributes are treated like user.* attributes */
static const struct xattr_handler cifs_os2_xattr_handler = {
.prefix = XATTR_OS2_PREFIX,
.flags = XATTR_USER,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
.name = CIFS_XATTR_CIFS_ACL,
.flags = XATTR_CIFS_ACL,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
.name = XATTR_NAME_POSIX_ACL_ACCESS,
.flags = XATTR_ACL_ACCESS,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
.name = XATTR_NAME_POSIX_ACL_DEFAULT,
.flags = XATTR_ACL_DEFAULT,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
const struct xattr_handler *cifs_xattr_handlers[] = {
&cifs_user_xattr_handler,
&cifs_os2_xattr_handler,
&cifs_cifs_acl_xattr_handler,
&cifs_posix_acl_access_xattr_handler,
&cifs_posix_acl_default_xattr_handler,
NULL
};