2 Unix SMB/CIFS implementation.
3 Check access to files based on security descriptors.
4 Copyright (C) Jeremy Allison 2005-2006.
5 Copyright (C) Michael Adam 2007.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "system/filesys.h"
23 #include "../libcli/security/security.h"
24 #include "../librpc/gen_ndr/ndr_security.h"
25 #include "smbd/smbd.h"
28 #define DBGC_CLASS DBGC_ACLS
30 /****************************************************************************
31 Actually emulate the in-kernel access checking for delete access. We need
32 this to successfully return ACCESS_DENIED on a file open for delete access.
33 ****************************************************************************/
35 bool can_delete_file_in_directory(connection_struct
*conn
,
36 struct files_struct
*dirfsp
,
37 const struct smb_filename
*smb_fname
)
39 struct smb_filename
*smb_fname_parent
= NULL
;
43 if (!CAN_WRITE(conn
)) {
47 if (!lp_acl_check_permissions(SNUM(conn
))) {
48 /* This option means don't check. */
52 if (get_current_uid(conn
) == (uid_t
)0) {
53 /* I'm sorry sir, I didn't know you were root... */
57 if (dirfsp
!= conn
->cwd_fsp
) {
58 smb_fname_parent
= dirfsp
->fsp_name
;
60 struct smb_filename
*atname
= NULL
;
62 * Get a pathref on the parent.
64 status
= parent_pathref(talloc_tos(),
69 if (!NT_STATUS_IS_OK(status
)) {
74 SMB_ASSERT(VALID_STAT(smb_fname_parent
->st
));
76 /* fast paths first */
78 if (!S_ISDIR(smb_fname_parent
->st
.st_ex_mode
)) {
84 /* sticky bit means delete only by owner of file or by root or
85 * by owner of directory. */
86 if (smb_fname_parent
->st
.st_ex_mode
& S_ISVTX
) {
87 if (!VALID_STAT(smb_fname
->st
)) {
88 /* If the file doesn't already exist then
89 * yes we'll be able to delete it. */
95 * Patch from SATOH Fumiyasu <fumiyas@miraclelinux.com>
96 * for bug #3348. Don't assume owning sticky bit
97 * directory means write access allowed.
98 * Fail to delete if we're not the owner of the file,
99 * or the owner of the directory as we have no possible
100 * chance of deleting. Otherwise, go on and check the ACL.
102 if ((get_current_uid(conn
) !=
103 smb_fname_parent
->st
.st_ex_uid
) &&
104 (get_current_uid(conn
) != smb_fname
->st
.st_ex_uid
)) {
105 DEBUG(10,("can_delete_file_in_directory: not "
106 "owner of file %s or directory %s",
107 smb_fname_str_dbg(smb_fname
),
108 smb_fname_str_dbg(smb_fname_parent
)));
115 /* now for ACL checks */
118 * There's two ways to get the permission to delete a file: First by
119 * having the DELETE bit on the file itself and second if that does
120 * not help, by the DELETE_CHILD bit on the containing directory.
122 * Here we only check the directory permissions, we will
123 * check the file DELETE permission separately.
126 ret
= NT_STATUS_IS_OK(smbd_check_access_rights_fsp(
128 smb_fname_parent
->fsp
,
132 if (smb_fname_parent
!= dirfsp
->fsp_name
) {
133 TALLOC_FREE(smb_fname_parent
);
138 /****************************************************************************
139 Userspace check for write access to fsp.
140 ****************************************************************************/
142 bool can_write_to_fsp(struct files_struct
*fsp
)
144 return NT_STATUS_IS_OK(smbd_check_access_rights_fsp(
151 /****************************************************************************
152 Check for an existing default Windows ACL on a directory fsp.
153 ****************************************************************************/
155 bool directory_has_default_acl_fsp(struct files_struct
*fsp
)
157 struct security_descriptor
*secdesc
= NULL
;
161 status
= SMB_VFS_FGET_NT_ACL(metadata_fsp(fsp
),
166 if (!NT_STATUS_IS_OK(status
) ||
168 secdesc
->dacl
== NULL
)
170 TALLOC_FREE(secdesc
);
174 for (i
= 0; i
< secdesc
->dacl
->num_aces
; i
++) {
175 struct security_ace
*psa
= &secdesc
->dacl
->aces
[i
];
177 if (psa
->flags
& (SEC_ACE_FLAG_OBJECT_INHERIT
|
178 SEC_ACE_FLAG_CONTAINER_INHERIT
))
180 TALLOC_FREE(secdesc
);
184 TALLOC_FREE(secdesc
);
188 /****************************************************************************
189 Check if setting delete on close is allowed on this fsp.
190 ****************************************************************************/
192 NTSTATUS
can_set_delete_on_close(files_struct
*fsp
, uint32_t dosmode
)
195 * Only allow delete on close for writable files.
198 if ((dosmode
& FILE_ATTRIBUTE_READONLY
) &&
199 !lp_delete_readonly(SNUM(fsp
->conn
))) {
200 DEBUG(10,("can_set_delete_on_close: file %s delete on close "
201 "flag set but file attribute is readonly.\n",
203 return NT_STATUS_CANNOT_DELETE
;
207 * Only allow delete on close for writable shares.
210 if (!CAN_WRITE(fsp
->conn
)) {
211 DEBUG(10,("can_set_delete_on_close: file %s delete on "
212 "close flag set but write access denied on share.\n",
214 return NT_STATUS_ACCESS_DENIED
;
218 * Only allow delete on close for files/directories opened with delete
222 if (!(fsp
->access_mask
& DELETE_ACCESS
)) {
223 DEBUG(10,("can_set_delete_on_close: file %s delete on "
224 "close flag set but delete access denied.\n",
226 return NT_STATUS_ACCESS_DENIED
;
229 /* Don't allow delete on close for non-empty directories. */
230 if (fsp
->fsp_flags
.is_directory
) {
231 SMB_ASSERT(!fsp_is_alternate_stream(fsp
));
233 /* Or the root of a share. */
234 if (ISDOT(fsp
->fsp_name
->base_name
)) {
235 DEBUG(10,("can_set_delete_on_close: can't set delete on "
236 "close for the root of a share.\n"));
237 return NT_STATUS_ACCESS_DENIED
;
240 return can_delete_directory_fsp(fsp
);