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/>.
23 extern struct current_user current_user;
26 #define DBGC_CLASS DBGC_ACLS
28 static bool can_access_file_acl(struct connection_struct *conn,
29 const char * fname, SMB_STRUCT_STAT *psbuf,
34 uint32_t access_granted;
35 struct security_descriptor *secdesc = NULL;
37 status = SMB_VFS_GET_NT_ACL(conn, fname,
38 (OWNER_SECURITY_INFORMATION |
39 GROUP_SECURITY_INFORMATION |
40 DACL_SECURITY_INFORMATION),
42 if (!NT_STATUS_IS_OK(status)) {
43 DEBUG(5, ("Could not get acl: %s\n", nt_errstr(status)));
47 result = se_access_check(secdesc, current_user.nt_user_token,
48 access_mask, &access_granted, &status);
53 /****************************************************************************
54 Actually emulate the in-kernel access checking for delete access. We need
55 this to successfully return ACCESS_DENIED on a file open for delete access.
56 ****************************************************************************/
58 bool can_delete_file_in_directory(connection_struct *conn, const char *fname)
61 TALLOC_CTX *ctx = talloc_tos();
64 if (!CAN_WRITE(conn)) {
68 /* Get the parent directory permission mask and owners. */
69 if (!parent_dirname_talloc(ctx,
75 if(SMB_VFS_STAT(conn, dname, &sbuf) != 0) {
79 /* fast paths first */
81 if (!S_ISDIR(sbuf.st_mode)) {
84 if (current_user.ut.uid == 0 || conn->admin_user) {
85 /* I'm sorry sir, I didn't know you were root... */
89 /* Check primary owner write access. */
90 if (current_user.ut.uid == sbuf.st_uid) {
91 return (sbuf.st_mode & S_IWUSR) ? True : False;
95 /* sticky bit means delete only by owner or root. */
96 if (sbuf.st_mode & S_ISVTX) {
97 SMB_STRUCT_STAT sbuf_file;
98 if(SMB_VFS_STAT(conn, fname, &sbuf_file) != 0) {
99 if (errno == ENOENT) {
100 /* If the file doesn't already exist then
101 * yes we'll be able to delete it. */
107 * Patch from SATOH Fumiyasu <fumiyas@miraclelinux.com>
108 * for bug #3348. Don't assume owning sticky bit
109 * directory means write access allowed.
111 if (current_user.ut.uid != sbuf_file.st_uid) {
117 /* now for ACL checks */
119 return can_access_file_acl(conn, dname, &sbuf, FILE_WRITE_DATA);
122 /****************************************************************************
123 Actually emulate the in-kernel access checking for read/write access. We need
124 this to successfully check for ability to write for dos filetimes.
125 Note this doesn't take into account share write permissions.
126 ****************************************************************************/
128 bool can_access_file(connection_struct *conn, const char *fname, SMB_STRUCT_STAT *psbuf, uint32 access_mask)
130 if (!(access_mask & (FILE_READ_DATA|FILE_WRITE_DATA))) {
133 access_mask &= (FILE_READ_DATA|FILE_WRITE_DATA);
135 /* some fast paths first */
137 DEBUG(10,("can_access_file: requesting 0x%x on file %s\n",
138 (unsigned int)access_mask, fname ));
140 if (current_user.ut.uid == 0 || conn->admin_user) {
141 /* I'm sorry sir, I didn't know you were root... */
145 if (!VALID_STAT(*psbuf)) {
146 /* Get the file permission mask and owners. */
147 if(SMB_VFS_STAT(conn, fname, psbuf) != 0) {
152 /* Check primary owner access. */
153 if (current_user.ut.uid == psbuf->st_uid) {
154 switch (access_mask) {
156 return (psbuf->st_mode & S_IRUSR) ? True : False;
158 case FILE_WRITE_DATA:
159 return (psbuf->st_mode & S_IWUSR) ? True : False;
161 default: /* FILE_READ_DATA|FILE_WRITE_DATA */
163 if ((psbuf->st_mode & (S_IWUSR|S_IRUSR)) == (S_IWUSR|S_IRUSR)) {
171 /* now for ACL checks */
173 return can_access_file_acl(conn, fname, psbuf, access_mask);
176 /****************************************************************************
177 Userspace check for write access.
178 Note this doesn't take into account share write permissions.
179 ****************************************************************************/
181 bool can_write_to_file(connection_struct *conn, const char *fname, SMB_STRUCT_STAT *psbuf)
183 return can_access_file(conn, fname, psbuf, FILE_WRITE_DATA);