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" /* DACL only */
36 #define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
37 #define CIFS_XATTR_ATTRIB "cifs.dosattrib" /* full name: user.cifs.dosattrib */
38 #define CIFS_XATTR_CREATETIME "cifs.creationtime" /* user.cifs.creationtime */
39 /*
40 * Although these three are just aliases for the above, need to move away from
41 * confusing users and using the 20+ year old term 'cifs' when it is no longer
42 * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
43 */
44 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
45 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
46 #define SMB3_XATTR_ATTRIB "smb3.dosattrib" /* full name: user.smb3.dosattrib */
47 #define SMB3_XATTR_CREATETIME "smb3.creationtime" /* user.smb3.creationtime */
48 /* BB need to add server (Samba e.g) support for security and trusted prefix */
49
50 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
51 XATTR_CIFS_NTSD };
52
cifs_attrib_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,char * full_path,const void * value,size_t size)53 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
54 struct inode *inode, char *full_path,
55 const void *value, size_t size)
56 {
57 ssize_t rc = -EOPNOTSUPP;
58 __u32 *pattrib = (__u32 *)value;
59 __u32 attrib;
60 FILE_BASIC_INFO info_buf;
61
62 if ((value == NULL) || (size != sizeof(__u32)))
63 return -ERANGE;
64
65 memset(&info_buf, 0, sizeof(info_buf));
66 attrib = *pattrib;
67 info_buf.Attributes = cpu_to_le32(attrib);
68 if (pTcon->ses->server->ops->set_file_info)
69 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
70 &info_buf, xid);
71 if (rc == 0)
72 CIFS_I(inode)->cifsAttrs = attrib;
73
74 return rc;
75 }
76
cifs_creation_time_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,char * full_path,const void * value,size_t size)77 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
78 struct inode *inode, char *full_path,
79 const void *value, size_t size)
80 {
81 ssize_t rc = -EOPNOTSUPP;
82 __u64 *pcreation_time = (__u64 *)value;
83 __u64 creation_time;
84 FILE_BASIC_INFO info_buf;
85
86 if ((value == NULL) || (size != sizeof(__u64)))
87 return -ERANGE;
88
89 memset(&info_buf, 0, sizeof(info_buf));
90 creation_time = *pcreation_time;
91 info_buf.CreationTime = cpu_to_le64(creation_time);
92 if (pTcon->ses->server->ops->set_file_info)
93 rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
94 &info_buf, xid);
95 if (rc == 0)
96 CIFS_I(inode)->createtime = creation_time;
97
98 return rc;
99 }
100
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)101 static int cifs_xattr_set(const struct xattr_handler *handler,
102 struct dentry *dentry, struct inode *inode,
103 const char *name, const void *value,
104 size_t size, int flags)
105 {
106 int rc = -EOPNOTSUPP;
107 unsigned int xid;
108 struct super_block *sb = dentry->d_sb;
109 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
110 struct tcon_link *tlink;
111 struct cifs_tcon *pTcon;
112 char *full_path;
113
114 tlink = cifs_sb_tlink(cifs_sb);
115 if (IS_ERR(tlink))
116 return PTR_ERR(tlink);
117 pTcon = tlink_tcon(tlink);
118
119 xid = get_xid();
120
121 full_path = build_path_from_dentry(dentry);
122 if (full_path == NULL) {
123 rc = -ENOMEM;
124 goto out;
125 }
126 /* return dos attributes as pseudo xattr */
127 /* return alt name if available as pseudo attr */
128
129 /* if proc/fs/cifs/streamstoxattr is set then
130 search server for EAs or streams to
131 returns as xattrs */
132 if (size > MAX_EA_VALUE_SIZE) {
133 cifs_dbg(FYI, "size of EA value too large\n");
134 rc = -EOPNOTSUPP;
135 goto out;
136 }
137
138 switch (handler->flags) {
139 case XATTR_USER:
140 cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
141 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
142 (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
143 rc = cifs_attrib_set(xid, pTcon, inode, full_path,
144 value, size);
145 if (rc == 0) /* force revalidate of the inode */
146 CIFS_I(inode)->time = 0;
147 break;
148 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
149 (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
150 rc = cifs_creation_time_set(xid, pTcon, inode,
151 full_path, value, size);
152 if (rc == 0) /* force revalidate of the inode */
153 CIFS_I(inode)->time = 0;
154 break;
155 }
156
157 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
158 goto out;
159
160 if (pTcon->ses->server->ops->set_EA) {
161 rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
162 full_path, name, value, (__u16)size,
163 cifs_sb->local_nls, cifs_sb);
164 if (rc == 0)
165 inode_set_ctime_current(inode);
166 }
167 break;
168
169 case XATTR_CIFS_ACL:
170 case XATTR_CIFS_NTSD: {
171 struct cifs_ntsd *pacl;
172
173 if (!value)
174 goto out;
175 pacl = kmalloc(size, GFP_KERNEL);
176 if (!pacl) {
177 rc = -ENOMEM;
178 } else {
179 memcpy(pacl, value, size);
180 if (value &&
181 pTcon->ses->server->ops->set_acl) {
182 rc = 0;
183 if (handler->flags == XATTR_CIFS_NTSD) {
184 /* set owner and DACL */
185 rc = pTcon->ses->server->ops->set_acl(
186 pacl, size, inode,
187 full_path,
188 CIFS_ACL_OWNER);
189 }
190 if (rc == 0) {
191 /* set DACL */
192 rc = pTcon->ses->server->ops->set_acl(
193 pacl, size, inode,
194 full_path,
195 CIFS_ACL_DACL);
196 }
197 } else {
198 rc = -EOPNOTSUPP;
199 }
200 if (rc == 0) /* force revalidate of the inode */
201 CIFS_I(inode)->time = 0;
202 kfree(pacl);
203 }
204 break;
205 }
206
207 case XATTR_ACL_ACCESS:
208 #ifdef CONFIG_CIFS_POSIX
209 if (!value)
210 goto out;
211 if (sb->s_flags & SB_POSIXACL)
212 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
213 value, (const int)size,
214 ACL_TYPE_ACCESS, cifs_sb->local_nls,
215 cifs_remap(cifs_sb));
216 #endif /* CONFIG_CIFS_POSIX */
217 break;
218
219 case XATTR_ACL_DEFAULT:
220 #ifdef CONFIG_CIFS_POSIX
221 if (!value)
222 goto out;
223 if (sb->s_flags & SB_POSIXACL)
224 rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
225 value, (const int)size,
226 ACL_TYPE_DEFAULT, cifs_sb->local_nls,
227 cifs_remap(cifs_sb));
228 #endif /* CONFIG_CIFS_POSIX */
229 break;
230 }
231
232 out:
233 kfree(full_path);
234 free_xid(xid);
235 cifs_put_tlink(tlink);
236 return rc;
237 }
238
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)239 static int cifs_attrib_get(struct dentry *dentry,
240 struct inode *inode, void *value,
241 size_t size)
242 {
243 ssize_t rc;
244 __u32 *pattribute;
245
246 rc = cifs_revalidate_dentry_attr(dentry);
247
248 if (rc)
249 return rc;
250
251 if ((value == NULL) || (size == 0))
252 return sizeof(__u32);
253 else if (size < sizeof(__u32))
254 return -ERANGE;
255
256 /* return dos attributes as pseudo xattr */
257 pattribute = (__u32 *)value;
258 *pattribute = CIFS_I(inode)->cifsAttrs;
259
260 return sizeof(__u32);
261 }
262
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)263 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
264 void *value, size_t size)
265 {
266 ssize_t rc;
267 __u64 *pcreatetime;
268
269 rc = cifs_revalidate_dentry_attr(dentry);
270 if (rc)
271 return rc;
272
273 if ((value == NULL) || (size == 0))
274 return sizeof(__u64);
275 else if (size < sizeof(__u64))
276 return -ERANGE;
277
278 /* return dos attributes as pseudo xattr */
279 pcreatetime = (__u64 *)value;
280 *pcreatetime = CIFS_I(inode)->createtime;
281 return sizeof(__u64);
282 }
283
284
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size,int flags)285 static int cifs_xattr_get(const struct xattr_handler *handler,
286 struct dentry *dentry, struct inode *inode,
287 const char *name, void *value, size_t size, int flags)
288 {
289 ssize_t rc = -EOPNOTSUPP;
290 unsigned int xid;
291 struct super_block *sb = dentry->d_sb;
292 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
293 struct tcon_link *tlink;
294 struct cifs_tcon *pTcon;
295 char *full_path;
296
297 tlink = cifs_sb_tlink(cifs_sb);
298 if (IS_ERR(tlink))
299 return PTR_ERR(tlink);
300 pTcon = tlink_tcon(tlink);
301
302 xid = get_xid();
303
304 full_path = build_path_from_dentry(dentry);
305 if (full_path == NULL) {
306 rc = -ENOMEM;
307 goto out;
308 }
309
310 /* return alt name if available as pseudo attr */
311 switch (handler->flags) {
312 case XATTR_USER:
313 cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
314 if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
315 (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
316 rc = cifs_attrib_get(dentry, inode, value, size);
317 break;
318 } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
319 (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
320 rc = cifs_creation_time_get(dentry, inode, value, size);
321 break;
322 }
323
324 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
325 goto out;
326
327 if (pTcon->ses->server->ops->query_all_EAs)
328 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
329 full_path, name, value, size, cifs_sb);
330 break;
331
332 case XATTR_CIFS_ACL:
333 case XATTR_CIFS_NTSD: {
334 /* the whole ntsd is fetched regardless */
335 u32 acllen;
336 struct cifs_ntsd *pacl;
337
338 if (pTcon->ses->server->ops->get_acl == NULL)
339 goto out; /* rc already EOPNOTSUPP */
340
341 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
342 inode, full_path, &acllen);
343 if (IS_ERR(pacl)) {
344 rc = PTR_ERR(pacl);
345 cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
346 __func__, rc);
347 } else {
348 if (value) {
349 if (acllen > size)
350 acllen = -ERANGE;
351 else
352 memcpy(value, pacl, acllen);
353 }
354 rc = acllen;
355 kfree(pacl);
356 }
357 break;
358 }
359
360 case XATTR_ACL_ACCESS:
361 #ifdef CONFIG_CIFS_POSIX
362 if (sb->s_flags & SB_POSIXACL)
363 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
364 value, size, ACL_TYPE_ACCESS,
365 cifs_sb->local_nls,
366 cifs_remap(cifs_sb));
367 #endif /* CONFIG_CIFS_POSIX */
368 break;
369
370 case XATTR_ACL_DEFAULT:
371 #ifdef CONFIG_CIFS_POSIX
372 if (sb->s_flags & SB_POSIXACL)
373 rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
374 value, size, ACL_TYPE_DEFAULT,
375 cifs_sb->local_nls,
376 cifs_remap(cifs_sb));
377 #endif /* CONFIG_CIFS_POSIX */
378 break;
379 }
380
381 /* We could add an additional check for streams ie
382 if proc/fs/cifs/streamstoxattr is set then
383 search server for EAs or streams to
384 returns as xattrs */
385
386 if (rc == -EINVAL)
387 rc = -EOPNOTSUPP;
388
389 out:
390 kfree(full_path);
391 free_xid(xid);
392 cifs_put_tlink(tlink);
393 return rc;
394 }
395
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)396 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
397 {
398 ssize_t rc = -EOPNOTSUPP;
399 unsigned int xid;
400 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
401 struct tcon_link *tlink;
402 struct cifs_tcon *pTcon;
403 char *full_path;
404
405 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
406 return -EOPNOTSUPP;
407
408 tlink = cifs_sb_tlink(cifs_sb);
409 if (IS_ERR(tlink))
410 return PTR_ERR(tlink);
411 pTcon = tlink_tcon(tlink);
412
413 xid = get_xid();
414
415 full_path = build_path_from_dentry(direntry);
416 if (full_path == NULL) {
417 rc = -ENOMEM;
418 goto list_ea_exit;
419 }
420 /* return dos attributes as pseudo xattr */
421 /* return alt name if available as pseudo attr */
422
423 /* if proc/fs/cifs/streamstoxattr is set then
424 search server for EAs or streams to
425 returns as xattrs */
426
427 if (pTcon->ses->server->ops->query_all_EAs)
428 rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
429 full_path, NULL, data, buf_size, cifs_sb);
430 list_ea_exit:
431 kfree(full_path);
432 free_xid(xid);
433 cifs_put_tlink(tlink);
434 return rc;
435 }
436
437 static const struct xattr_handler cifs_user_xattr_handler = {
438 .prefix = XATTR_USER_PREFIX,
439 .flags = XATTR_USER,
440 .get = cifs_xattr_get,
441 .set = cifs_xattr_set,
442 };
443
444 /* os2.* attributes are treated like user.* attributes */
445 static const struct xattr_handler cifs_os2_xattr_handler = {
446 .prefix = XATTR_OS2_PREFIX,
447 .flags = XATTR_USER,
448 .get = cifs_xattr_get,
449 .set = cifs_xattr_set,
450 };
451
452 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
453 .name = CIFS_XATTR_CIFS_ACL,
454 .flags = XATTR_CIFS_ACL,
455 .get = cifs_xattr_get,
456 .set = cifs_xattr_set,
457 };
458
459 /*
460 * Although this is just an alias for the above, need to move away from
461 * confusing users and using the 20 year old term 'cifs' when it is no
462 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
463 * SMB3 and later are highly secure.
464 */
465 static const struct xattr_handler smb3_acl_xattr_handler = {
466 .name = SMB3_XATTR_CIFS_ACL,
467 .flags = XATTR_CIFS_ACL,
468 .get = cifs_xattr_get,
469 .set = cifs_xattr_set,
470 };
471
472 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
473 .name = CIFS_XATTR_CIFS_NTSD,
474 .flags = XATTR_CIFS_NTSD,
475 .get = cifs_xattr_get,
476 .set = cifs_xattr_set,
477 };
478
479 /*
480 * Although this is just an alias for the above, need to move away from
481 * confusing users and using the 20 year old term 'cifs' when it is no
482 * longer secure and was replaced by SMB2/SMB3 a long time ago, and
483 * SMB3 and later are highly secure.
484 */
485 static const struct xattr_handler smb3_ntsd_xattr_handler = {
486 .name = SMB3_XATTR_CIFS_NTSD,
487 .flags = XATTR_CIFS_NTSD,
488 .get = cifs_xattr_get,
489 .set = cifs_xattr_set,
490 };
491
492 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
493 .name = XATTR_NAME_POSIX_ACL_ACCESS,
494 .flags = XATTR_ACL_ACCESS,
495 .get = cifs_xattr_get,
496 .set = cifs_xattr_set,
497 };
498
499 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
500 .name = XATTR_NAME_POSIX_ACL_DEFAULT,
501 .flags = XATTR_ACL_DEFAULT,
502 .get = cifs_xattr_get,
503 .set = cifs_xattr_set,
504 };
505
506 const struct xattr_handler *cifs_xattr_handlers[] = {
507 &cifs_user_xattr_handler,
508 &cifs_os2_xattr_handler,
509 &cifs_cifs_acl_xattr_handler,
510 &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
511 &cifs_cifs_ntsd_xattr_handler,
512 &smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
513 &cifs_posix_acl_access_xattr_handler,
514 &cifs_posix_acl_default_xattr_handler,
515 NULL
516 };
517