1 /*
2 * fs/cifs/xattr.c
3 *
4 * Copyright (c) International Business Machines Corp., 2003, 2007
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library 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
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/fs.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/slab.h>
25 #include <linux/xattr.h>
26 #include "cifsfs.h"
27 #include "cifspdu.h"
28 #include "cifsglob.h"
29 #include "cifsproto.h"
30 #include "cifs_debug.h"
31 #include "cifs_fs_sb.h"
32 #include "cifs_unicode.h"
33
34 #define MAX_EA_VALUE_SIZE CIFSMaxBufSize
35 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl"
36 #define CIFS_XATTR_ATTRIB "cifs.dosattrib" /* full name: user.cifs.dosattrib */
37 #define CIFS_XATTR_CREATETIME "cifs.creationtime" /* user.cifs.creationtime */
38 /*
39 * Although these three are just aliases for the above, need to move away from
40 * confusing users and using the 20+ year old term 'cifs' when it is no longer
41 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
42 */
43 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl"
44 #define SMB3_XATTR_ATTRIB "smb3.dosattrib" /* full name: user.smb3.dosattrib */
45 #define SMB3_XATTR_CREATETIME "smb3.creationtime" /* user.smb3.creationtime */
46 /* BB need to add server (Samba e.g) support for security and trusted prefix */
47
48 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT };
49
cifs_xattr_set(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)50 static int cifs_xattr_set(const struct xattr_handler *handler,
51 struct dentry *dentry, struct inode *inode,
52 const char *name, const void *value,
53 size_t size, int flags)
54 {
55 int rc = -EOPNOTSUPP;
56 unsigned int xid;
57 struct super_block *sb = dentry->d_sb;
58 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
59 struct tcon_link *tlink;
60 struct cifs_tcon *pTcon;
61 char *full_path;
62
63 tlink = cifs_sb_tlink(cifs_sb);
64 if (IS_ERR(tlink))
65 return PTR_ERR(tlink);
66 pTcon = tlink_tcon(tlink);
67
68 xid = get_xid();
69
70 full_path = build_path_from_dentry(dentry);
71 if (full_path == NULL) {
72 rc = -ENOMEM;
73 goto out;
74 }
75 /* return dos attributes as pseudo xattr */
76 /* return alt name if available as pseudo attr */
77
78 /* if proc/fs/cifs/streamstoxattr is set then
79 search server for EAs or streams to
80 returns as xattrs */
81 if (size > MAX_EA_VALUE_SIZE) {
82 cifs_dbg(FYI, "size of EA value too large\n");
83 rc = -EOPNOTSUPP;
84 goto out;
85 }
86
87 switch (handler->flags) {
88 case XATTR_USER:
89 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
90 goto out;
91
92 if (pTcon->ses->server->ops->set_EA)
93 rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
94 full_path, name, value, (__u16)size,
95 cifs_sb->local_nls, cifs_sb);
96 break;
97
98 case XATTR_CIFS_ACL: {
99 #ifdef CONFIG_CIFS_ACL
100 struct cifs_ntsd *pacl;
101
102 if (!value)
103 goto out;
104 pacl = kmalloc(size, GFP_KERNEL);
105 if (!pacl) {
106 rc = -ENOMEM;
107 } else {
108 memcpy(pacl, value, size);
109 if (value &&
110 pTcon->ses->server->ops->set_acl)
111 rc = pTcon->ses->server->ops->set_acl(pacl,
112 size, inode,
113 full_path, CIFS_ACL_DACL);
114 else
115 rc = -EOPNOTSUPP;
116 if (rc == 0) /* force revalidate of the inode */
117 CIFS_I(inode)->time = 0;
118 kfree(pacl);
119 }
120 #endif /* CONFIG_CIFS_ACL */
121 break;
122 }
123
124 case XATTR_ACL_ACCESS:
125 #ifdef CONFIG_CIFS_POSIX
126 if (!value)
127 goto out;
128 if (sb->s_flags & SB_POSIXACL)
129 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
130 value, (const int)size,
131 ACL_TYPE_ACCESS, cifs_sb->local_nls,
132 cifs_remap(cifs_sb));
133 #endif /* CONFIG_CIFS_POSIX */
134 break;
135
136 case XATTR_ACL_DEFAULT:
137 #ifdef CONFIG_CIFS_POSIX
138 if (!value)
139 goto out;
140 if (sb->s_flags & SB_POSIXACL)
141 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
142 value, (const int)size,
143 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
144 cifs_remap(cifs_sb));
145 #endif /* CONFIG_CIFS_POSIX */
146 break;
147 }
148
149 out:
150 kfree(full_path);
151 free_xid(xid);
152 cifs_put_tlink(tlink);
153 return rc;
154 }
155
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)156 static int cifs_attrib_get(struct dentry *dentry,
157 struct inode *inode, void *value,
158 size_t size)
159 {
160 ssize_t rc;
161 __u32 *pattribute;
162
163 rc = cifs_revalidate_dentry_attr(dentry);
164
165 if (rc)
166 return rc;
167
168 if ((value == NULL) || (size == 0))
169 return sizeof(__u32);
170 else if (size < sizeof(__u32))
171 return -ERANGE;
172
173 /* return dos attributes as pseudo xattr */
174 pattribute = (__u32 *)value;
175 *pattribute = CIFS_I(inode)->cifsAttrs;
176
177 return sizeof(__u32);
178 }
179
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)180 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
181 void *value, size_t size)
182 {
183 ssize_t rc;
184 __u64 * pcreatetime;
185
186 rc = cifs_revalidate_dentry_attr(dentry);
187 if (rc)
188 return rc;
189
190 if ((value == NULL) || (size == 0))
191 return sizeof(__u64);
192 else if (size < sizeof(__u64))
193 return -ERANGE;
194
195 /* return dos attributes as pseudo xattr */
196 pcreatetime = (__u64 *)value;
197 *pcreatetime = CIFS_I(inode)->createtime;
198 return sizeof(__u64);
199 }
200
201
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)202 static int cifs_xattr_get(const struct xattr_handler *handler,
203 struct dentry *dentry, struct inode *inode,
204 const char *name, void *value, size_t size)
205 {
206 ssize_t rc = -EOPNOTSUPP;
207 unsigned int xid;
208 struct super_block *sb = dentry->d_sb;
209 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
210 struct tcon_link *tlink;
211 struct cifs_tcon *pTcon;
212 char *full_path;
213
214 tlink = cifs_sb_tlink(cifs_sb);
215 if (IS_ERR(tlink))
216 return PTR_ERR(tlink);
217 pTcon = tlink_tcon(tlink);
218
219 xid = get_xid();
220
221 full_path = build_path_from_dentry(dentry);
222 if (full_path == NULL) {
223 rc = -ENOMEM;
224 goto out;
225 }
226
227 /* return alt name if available as pseudo attr */
228 switch (handler->flags) {
229 case XATTR_USER:
230 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
231 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
232 (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
233 rc = cifs_attrib_get(dentry, inode, value, size);
234 break;
235 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
236 (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
237 rc = cifs_creation_time_get(dentry, inode, value, size);
238 break;
239 }
240
241 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
242 goto out;
243
244 if (pTcon->ses->server->ops->query_all_EAs)
245 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
246 full_path, name, value, size, cifs_sb);
247 break;
248
249 case XATTR_CIFS_ACL: {
250 #ifdef CONFIG_CIFS_ACL
251 u32 acllen;
252 struct cifs_ntsd *pacl;
253
254 if (pTcon->ses->server->ops->get_acl == NULL)
255 goto out; /* rc already EOPNOTSUPP */
256
257 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
258 inode, full_path, &acllen);
259 if (IS_ERR(pacl)) {
260 rc = PTR_ERR(pacl);
261 cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
262 __func__, rc);
263 } else {
264 if (value) {
265 if (acllen > size)
266 acllen = -ERANGE;
267 else
268 memcpy(value, pacl, acllen);
269 }
270 rc = acllen;
271 kfree(pacl);
272 }
273 #endif /* CONFIG_CIFS_ACL */
274 break;
275 }
276
277 case XATTR_ACL_ACCESS:
278 #ifdef CONFIG_CIFS_POSIX
279 if (sb->s_flags & SB_POSIXACL)
280 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
281 value, size, ACL_TYPE_ACCESS,
282 cifs_sb->local_nls,
283 cifs_remap(cifs_sb));
284 #endif /* CONFIG_CIFS_POSIX */
285 break;
286
287 case XATTR_ACL_DEFAULT:
288 #ifdef CONFIG_CIFS_POSIX
289 if (sb->s_flags & SB_POSIXACL)
290 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
291 value, size, ACL_TYPE_DEFAULT,
292 cifs_sb->local_nls,
293 cifs_remap(cifs_sb));
294 #endif /* CONFIG_CIFS_POSIX */
295 break;
296 }
297
298 /* We could add an additional check for streams ie
299 if proc/fs/cifs/streamstoxattr is set then
300 search server for EAs or streams to
301 returns as xattrs */
302
303 if (rc == -EINVAL)
304 rc = -EOPNOTSUPP;
305
306 out:
307 kfree(full_path);
308 free_xid(xid);
309 cifs_put_tlink(tlink);
310 return rc;
311 }
312
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)313 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
314 {
315 ssize_t rc = -EOPNOTSUPP;
316 unsigned int xid;
317 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
318 struct tcon_link *tlink;
319 struct cifs_tcon *pTcon;
320 char *full_path;
321
322 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
323 return -EOPNOTSUPP;
324
325 tlink = cifs_sb_tlink(cifs_sb);
326 if (IS_ERR(tlink))
327 return PTR_ERR(tlink);
328 pTcon = tlink_tcon(tlink);
329
330 xid = get_xid();
331
332 full_path = build_path_from_dentry(direntry);
333 if (full_path == NULL) {
334 rc = -ENOMEM;
335 goto list_ea_exit;
336 }
337 /* return dos attributes as pseudo xattr */
338 /* return alt name if available as pseudo attr */
339
340 /* if proc/fs/cifs/streamstoxattr is set then
341 search server for EAs or streams to
342 returns as xattrs */
343
344 if (pTcon->ses->server->ops->query_all_EAs)
345 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
346 full_path, NULL, data, buf_size, cifs_sb);
347 list_ea_exit:
348 kfree(full_path);
349 free_xid(xid);
350 cifs_put_tlink(tlink);
351 return rc;
352 }
353
354 static const struct xattr_handler cifs_user_xattr_handler = {
355 .prefix = XATTR_USER_PREFIX,
356 .flags = XATTR_USER,
357 .get = cifs_xattr_get,
358 .set = cifs_xattr_set,
359 };
360
361 /* os2.* attributes are treated like user.* attributes */
362 static const struct xattr_handler cifs_os2_xattr_handler = {
363 .prefix = XATTR_OS2_PREFIX,
364 .flags = XATTR_USER,
365 .get = cifs_xattr_get,
366 .set = cifs_xattr_set,
367 };
368
369 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
370 .name = CIFS_XATTR_CIFS_ACL,
371 .flags = XATTR_CIFS_ACL,
372 .get = cifs_xattr_get,
373 .set = cifs_xattr_set,
374 };
375
376 /*
377 * Although this is just an alias for the above, need to move away from
378 * confusing users and using the 20 year old term 'cifs' when it is no
379 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
380 * SMB3 and later are highly secure.
381 */
382 static const struct xattr_handler smb3_acl_xattr_handler = {
383 .name = SMB3_XATTR_CIFS_ACL,
384 .flags = XATTR_CIFS_ACL,
385 .get = cifs_xattr_get,
386 .set = cifs_xattr_set,
387 };
388
389 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
390 .name = XATTR_NAME_POSIX_ACL_ACCESS,
391 .flags = XATTR_ACL_ACCESS,
392 .get = cifs_xattr_get,
393 .set = cifs_xattr_set,
394 };
395
396 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
397 .name = XATTR_NAME_POSIX_ACL_DEFAULT,
398 .flags = XATTR_ACL_DEFAULT,
399 .get = cifs_xattr_get,
400 .set = cifs_xattr_set,
401 };
402
403 const struct xattr_handler *cifs_xattr_handlers[] = {
404 &cifs_user_xattr_handler,
405 &cifs_os2_xattr_handler,
406 &cifs_cifs_acl_xattr_handler,
407 &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
408 &cifs_posix_acl_access_xattr_handler,
409 &cifs_posix_acl_default_xattr_handler,
410 NULL
411 };
412