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linux-hardened/fs/cifs/xattr.c
Steve French 2baa268253 Remap reserved posix characters by default (part 3/3) 
This is a bigger patch, but its size is mostly due to
a single change for how we check for remapping illegal characters
in file names - a lot of repeated, small changes to
the way callers request converting file names.

The final patch in the series does the following:

1) changes default behavior for cifs to be more intuitive.
Currently we do not map by default to seven reserved characters,
ie those valid in POSIX but not in NTFS/CIFS/SMB3/Windows,
unless a mount option (mapchars) is specified.  Change this
to by default always map and map using the SFM maping
(like the Mac uses) unless the server negotiates the CIFS Unix
Extensions (like Samba does when mounting with the cifs protocol)
when the remapping of the characters is unnecessary.  This should
help SMB3 mounts in particular since Samba will likely be
able to implement this mapping with its new "vfs_fruit" module
as it will be doing for the Mac.
2) if the user specifies the existing "mapchars" mount option then
use the "SFU" (Microsoft Services for Unix, SUA) style mapping of
the seven characters instead.
3) if the user specifies "nomapposix" then disable SFM/MAC style mapping
(so no character remapping would be used unless the user specifies
"mapchars" on mount as well, as above).
4) change all the places in the code that check for the superblock
flag on the mount which is set by mapchars and passed in on all
path based operation and change it to use a small function call
instead to set the mapping type properly (and check for the
mapping type in the cifs unicode functions)

Signed-off-by: Steve French <smfrench@gmail.com>
2014-10-16 15:20:20 -05:00

424 lines
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/*
* 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_DOS_ATTRIB "user.DosAttrib"
#define CIFS_XATTR_CIFS_ACL "system.cifs_acl"
/* BB need to add server (Samba e.g) support for security and trusted prefix */
int cifs_removexattr(struct dentry *direntry, const char *ea_name)
{
int rc = -EOPNOTSUPP;
#ifdef CONFIG_CIFS_XATTR
unsigned int xid;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct super_block *sb;
char *full_path = NULL;
if (direntry == NULL)
return -EIO;
if (direntry->d_inode == NULL)
return -EIO;
sb = direntry->d_inode->i_sb;
if (sb == NULL)
return -EIO;
cifs_sb = CIFS_SB(sb);
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 remove_ea_exit;
}
if (ea_name == NULL) {
cifs_dbg(FYI, "Null xattr names not supported\n");
} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
&& (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))) {
cifs_dbg(FYI,
"illegal xattr request %s (only user namespace supported)\n",
ea_name);
/* BB what if no namespace prefix? */
/* Should we just pass them to server, except for
system and perhaps security prefixes? */
} else {
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto remove_ea_exit;
ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
if (pTcon->ses->server->ops->set_EA)
rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
full_path, ea_name, NULL, (__u16)0,
cifs_sb->local_nls, cifs_remap(cifs_sb));
}
remove_ea_exit:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
#endif
return rc;
}
int cifs_setxattr(struct dentry *direntry, const char *ea_name,
const void *ea_value, size_t value_size, int flags)
{
int rc = -EOPNOTSUPP;
#ifdef CONFIG_CIFS_XATTR
unsigned int xid;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct super_block *sb;
char *full_path;
if (direntry == NULL)
return -EIO;
if (direntry->d_inode == NULL)
return -EIO;
sb = direntry->d_inode->i_sb;
if (sb == NULL)
return -EIO;
cifs_sb = CIFS_SB(sb);
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 set_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 (value_size > MAX_EA_VALUE_SIZE) {
cifs_dbg(FYI, "size of EA value too large\n");
rc = -EOPNOTSUPP;
goto set_ea_exit;
}
if (ea_name == NULL) {
cifs_dbg(FYI, "Null xattr names not supported\n");
} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
== 0) {
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto set_ea_exit;
if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0)
cifs_dbg(FYI, "attempt to set cifs inode metadata\n");
ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
if (pTcon->ses->server->ops->set_EA)
rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
full_path, ea_name, ea_value, (__u16)value_size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)
== 0) {
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto set_ea_exit;
ea_name += XATTR_OS2_PREFIX_LEN; /* skip past os2. prefix */
if (pTcon->ses->server->ops->set_EA)
rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
full_path, ea_name, ea_value, (__u16)value_size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
} else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
#ifdef CONFIG_CIFS_ACL
struct cifs_ntsd *pacl;
pacl = kmalloc(value_size, GFP_KERNEL);
if (!pacl) {
rc = -ENOMEM;
} else {
memcpy(pacl, ea_value, value_size);
if (pTcon->ses->server->ops->set_acl)
rc = pTcon->ses->server->ops->set_acl(pacl,
value_size, direntry->d_inode,
full_path, CIFS_ACL_DACL);
else
rc = -EOPNOTSUPP;
if (rc == 0) /* force revalidate of the inode */
CIFS_I(direntry->d_inode)->time = 0;
kfree(pacl);
}
#else
cifs_dbg(FYI, "Set CIFS ACL not supported yet\n");
#endif /* CONFIG_CIFS_ACL */
} else {
int temp;
temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
strlen(POSIX_ACL_XATTR_ACCESS));
if (temp == 0) {
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
ea_value, (const int)value_size,
ACL_TYPE_ACCESS, cifs_sb->local_nls,
cifs_remap(cifs_sb));
cifs_dbg(FYI, "set POSIX ACL rc %d\n", rc);
#else
cifs_dbg(FYI, "set POSIX ACL not supported\n");
#endif
} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
ea_value, (const int)value_size,
ACL_TYPE_DEFAULT, cifs_sb->local_nls,
cifs_remap(cifs_sb));
cifs_dbg(FYI, "set POSIX default ACL rc %d\n", rc);
#else
cifs_dbg(FYI, "set default POSIX ACL not supported\n");
#endif
} else {
cifs_dbg(FYI, "illegal xattr request %s (only user namespace supported)\n",
ea_name);
/* BB what if no namespace prefix? */
/* Should we just pass them to server, except for
system and perhaps security prefixes? */
}
}
set_ea_exit:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
#endif
return rc;
}
ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
void *ea_value, size_t buf_size)
{
ssize_t rc = -EOPNOTSUPP;
#ifdef CONFIG_CIFS_XATTR
unsigned int xid;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct super_block *sb;
char *full_path;
if (direntry == NULL)
return -EIO;
if (direntry->d_inode == NULL)
return -EIO;
sb = direntry->d_inode->i_sb;
if (sb == NULL)
return -EIO;
cifs_sb = CIFS_SB(sb);
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 get_ea_exit;
}
/* return dos attributes as pseudo xattr */
/* return alt name if available as pseudo attr */
if (ea_name == NULL) {
cifs_dbg(FYI, "Null xattr names not supported\n");
} else if (strncmp(ea_name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)
== 0) {
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto get_ea_exit;
if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0) {
cifs_dbg(FYI, "attempt to query cifs inode metadata\n");
/* revalidate/getattr then populate from inode */
} /* BB add else when above is implemented */
ea_name += XATTR_USER_PREFIX_LEN; /* skip past user. prefix */
if (pTcon->ses->server->ops->query_all_EAs)
rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
full_path, ea_name, ea_value, buf_size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
} else if (strncmp(ea_name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
goto get_ea_exit;
ea_name += XATTR_OS2_PREFIX_LEN; /* skip past os2. prefix */
if (pTcon->ses->server->ops->query_all_EAs)
rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
full_path, ea_name, ea_value, buf_size,
cifs_sb->local_nls, cifs_remap(cifs_sb));
} else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,
strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
ea_value, buf_size, ACL_TYPE_ACCESS,
cifs_sb->local_nls,
cifs_remap(cifs_sb));
#else
cifs_dbg(FYI, "Query POSIX ACL not supported yet\n");
#endif /* CONFIG_CIFS_POSIX */
} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {
#ifdef CONFIG_CIFS_POSIX
if (sb->s_flags & MS_POSIXACL)
rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
ea_value, buf_size, ACL_TYPE_DEFAULT,
cifs_sb->local_nls,
cifs_remap(cifs_sb));
#else
cifs_dbg(FYI, "Query POSIX default ACL not supported yet\n");
#endif /* CONFIG_CIFS_POSIX */
} else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
#ifdef CONFIG_CIFS_ACL
u32 acllen;
struct cifs_ntsd *pacl;
if (pTcon->ses->server->ops->get_acl == NULL)
goto get_ea_exit; /* rc already EOPNOTSUPP */
pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
direntry->d_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 (ea_value) {
if (acllen > buf_size)
acllen = -ERANGE;
else
memcpy(ea_value, pacl, acllen);
}
rc = acllen;
kfree(pacl);
}
#else
cifs_dbg(FYI, "Query CIFS ACL not supported yet\n");
#endif /* CONFIG_CIFS_ACL */
} else if (strncmp(ea_name,
XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0) {
cifs_dbg(FYI, "Trusted xattr namespace not supported yet\n");
} else if (strncmp(ea_name,
XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0) {
cifs_dbg(FYI, "Security xattr namespace not supported yet\n");
} else
cifs_dbg(FYI,
"illegal xattr request %s (only user namespace supported)\n",
ea_name);
/* 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;
get_ea_exit:
kfree(full_path);
free_xid(xid);
cifs_put_tlink(tlink);
#endif
return rc;
}
ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
{
ssize_t rc = -EOPNOTSUPP;
#ifdef CONFIG_CIFS_XATTR
unsigned int xid;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct super_block *sb;
char *full_path;
if (direntry == NULL)
return -EIO;
if (direntry->d_inode == NULL)
return -EIO;
sb = direntry->d_inode->i_sb;
if (sb == NULL)
return -EIO;
cifs_sb = CIFS_SB(sb);
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);
#endif
return rc;
}
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