linux/fs/cifs/xattr.c
Christian Brauner c39c07fce7
cifs: use stub posix acl handlers
Now that cifs supports the get and set acl inode operations and the vfs
has been switched to the new posi api, cifs can simply rely on the stub
posix acl handlers. The custom xattr handlers and associated unused
helpers can be removed.

Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:32 +02:00

496 lines
13 KiB
C

// SPDX-License-Identifier: LGPL-2.1
/*
*
* Copyright (c) International Business Machines Corp., 2003, 2007
* Author(s): Steve French (sfrench@us.ibm.com)
*
*/
#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"
#include "cifs_ioctl.h"
#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
#define CIFS_XATTR_ATTRIB "cifs.dosattrib" /* full name: user.cifs.dosattrib */
#define CIFS_XATTR_CREATETIME "cifs.creationtime" /* user.cifs.creationtime */
/*
* Although these three are just aliases for the above, need to move away from
* confusing users and using the 20+ year old term 'cifs' when it is no longer
* secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
*/
#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
#define SMB3_XATTR_ATTRIB "smb3.dosattrib" /* full name: user.smb3.dosattrib */
#define SMB3_XATTR_CREATETIME "smb3.creationtime" /* user.smb3.creationtime */
/* 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,
XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
struct inode *inode, const char *full_path,
const void *value, size_t size)
{
ssize_t rc = -EOPNOTSUPP;
__u32 *pattrib = (__u32 *)value;
__u32 attrib;
FILE_BASIC_INFO info_buf;
if ((value == NULL) || (size != sizeof(__u32)))
return -ERANGE;
memset(&info_buf, 0, sizeof(info_buf));
attrib = *pattrib;
info_buf.Attributes = cpu_to_le32(attrib);
if (pTcon->ses->server->ops->set_file_info)
rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
&info_buf, xid);
if (rc == 0)
CIFS_I(inode)->cifsAttrs = attrib;
return rc;
}
static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
struct inode *inode, const char *full_path,
const void *value, size_t size)
{
ssize_t rc = -EOPNOTSUPP;
__u64 *pcreation_time = (__u64 *)value;
__u64 creation_time;
FILE_BASIC_INFO info_buf;
if ((value == NULL) || (size != sizeof(__u64)))
return -ERANGE;
memset(&info_buf, 0, sizeof(info_buf));
creation_time = *pcreation_time;
info_buf.CreationTime = cpu_to_le64(creation_time);
if (pTcon->ses->server->ops->set_file_info)
rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
&info_buf, xid);
if (rc == 0)
CIFS_I(inode)->createtime = creation_time;
return rc;
}
static int cifs_xattr_set(const struct xattr_handler *handler,
struct user_namespace *mnt_userns,
struct dentry *dentry, struct inode *inode,
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;
const char *full_path;
void *page;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
page = alloc_dentry_path();
full_path = build_path_from_dentry(dentry, page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
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:
cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
(strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
rc = cifs_attrib_set(xid, pTcon, inode, full_path,
value, size);
if (rc == 0) /* force revalidate of the inode */
CIFS_I(inode)->time = 0;
break;
} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
(strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
rc = cifs_creation_time_set(xid, pTcon, inode,
full_path, value, size);
if (rc == 0) /* force revalidate of the inode */
CIFS_I(inode)->time = 0;
break;
}
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_sb);
break;
case XATTR_CIFS_ACL:
case XATTR_CIFS_NTSD:
case XATTR_CIFS_NTSD_FULL: {
struct cifs_ntsd *pacl;
if (!value)
goto out;
pacl = kmalloc(size, GFP_KERNEL);
if (!pacl) {
rc = -ENOMEM;
} else {
memcpy(pacl, value, size);
if (pTcon->ses->server->ops->set_acl) {
int aclflags = 0;
rc = 0;
switch (handler->flags) {
case XATTR_CIFS_NTSD_FULL:
aclflags = (CIFS_ACL_OWNER |
CIFS_ACL_GROUP |
CIFS_ACL_DACL |
CIFS_ACL_SACL);
break;
case XATTR_CIFS_NTSD:
aclflags = (CIFS_ACL_OWNER |
CIFS_ACL_GROUP |
CIFS_ACL_DACL);
break;
case XATTR_CIFS_ACL:
default:
aclflags = CIFS_ACL_DACL;
}
rc = pTcon->ses->server->ops->set_acl(pacl,
size, inode, full_path, aclflags);
} else {
rc = -EOPNOTSUPP;
}
if (rc == 0) /* force revalidate of the inode */
CIFS_I(inode)->time = 0;
kfree(pacl);
}
break;
}
}
out:
free_dentry_path(page);
free_xid(xid);
cifs_put_tlink(tlink);
return rc;
}
static int cifs_attrib_get(struct dentry *dentry,
struct inode *inode, void *value,
size_t size)
{
ssize_t rc;
__u32 *pattribute;
rc = cifs_revalidate_dentry_attr(dentry);
if (rc)
return rc;
if ((value == NULL) || (size == 0))
return sizeof(__u32);
else if (size < sizeof(__u32))
return -ERANGE;
/* return dos attributes as pseudo xattr */
pattribute = (__u32 *)value;
*pattribute = CIFS_I(inode)->cifsAttrs;
return sizeof(__u32);
}
static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
void *value, size_t size)
{
ssize_t rc;
__u64 *pcreatetime;
rc = cifs_revalidate_dentry_attr(dentry);
if (rc)
return rc;
if ((value == NULL) || (size == 0))
return sizeof(__u64);
else if (size < sizeof(__u64))
return -ERANGE;
/* return dos attributes as pseudo xattr */
pcreatetime = (__u64 *)value;
*pcreatetime = CIFS_I(inode)->createtime;
return sizeof(__u64);
}
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;
const char *full_path;
void *page;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
page = alloc_dentry_path();
full_path = build_path_from_dentry(dentry, page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
goto out;
}
/* return alt name if available as pseudo attr */
switch (handler->flags) {
case XATTR_USER:
cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
(strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
rc = cifs_attrib_get(dentry, inode, value, size);
break;
} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
(strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
rc = cifs_creation_time_get(dentry, inode, value, size);
break;
}
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);
break;
case XATTR_CIFS_ACL:
case XATTR_CIFS_NTSD:
case XATTR_CIFS_NTSD_FULL: {
/*
* fetch owner, DACL, and SACL if asked for full descriptor,
* fetch owner and DACL otherwise
*/
u32 acllen, extra_info;
struct cifs_ntsd *pacl;
if (pTcon->ses->server->ops->get_acl == NULL)
goto out; /* rc already EOPNOTSUPP */
if (handler->flags == XATTR_CIFS_NTSD_FULL) {
extra_info = SACL_SECINFO;
} else {
extra_info = 0;
}
pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
inode, full_path, &acllen, extra_info);
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);
}
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:
free_dentry_path(page);
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;
const char *full_path;
void *page;
if (unlikely(cifs_forced_shutdown(cifs_sb)))
return -EIO;
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();
page = alloc_dentry_path();
full_path = build_path_from_dentry(direntry, page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
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);
list_ea_exit:
free_dentry_path(page);
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,
};
/*
* Although this is just an alias for the above, need to move away from
* confusing users and using the 20 year old term 'cifs' when it is no
* longer secure and was replaced by SMB2/SMB3 a long time ago, and
* SMB3 and later are highly secure.
*/
static const struct xattr_handler smb3_acl_xattr_handler = {
.name = SMB3_XATTR_CIFS_ACL,
.flags = XATTR_CIFS_ACL,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
.name = CIFS_XATTR_CIFS_NTSD,
.flags = XATTR_CIFS_NTSD,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
/*
* Although this is just an alias for the above, need to move away from
* confusing users and using the 20 year old term 'cifs' when it is no
* longer secure and was replaced by SMB2/SMB3 a long time ago, and
* SMB3 and later are highly secure.
*/
static const struct xattr_handler smb3_ntsd_xattr_handler = {
.name = SMB3_XATTR_CIFS_NTSD,
.flags = XATTR_CIFS_NTSD,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
.name = CIFS_XATTR_CIFS_NTSD_FULL,
.flags = XATTR_CIFS_NTSD_FULL,
.get = cifs_xattr_get,
.set = cifs_xattr_set,
};
/*
* Although this is just an alias for the above, need to move away from
* confusing users and using the 20 year old term 'cifs' when it is no
* longer secure and was replaced by SMB2/SMB3 a long time ago, and
* SMB3 and later are highly secure.
*/
static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
.name = SMB3_XATTR_CIFS_NTSD_FULL,
.flags = XATTR_CIFS_NTSD_FULL,
.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,
&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
&cifs_cifs_ntsd_xattr_handler,
&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
&cifs_cifs_ntsd_full_xattr_handler,
&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
#ifdef CONFIG_FS_POSIX_ACL
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
#endif
NULL
};