xref: /linux/fs/smb/client/xattr.c (revision e3966940559d52aa1800a008dcfeec218dd31f88)
1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3  *
4  *   Copyright (c) International Business Machines  Corp., 2003, 2007
5  *   Author(s): Steve French (sfrench@us.ibm.com)
6  *
7  */
8 
9 #include <linux/fs.h>
10 #include <linux/posix_acl_xattr.h>
11 #include <linux/slab.h>
12 #include <linux/xattr.h>
13 #include "cifsfs.h"
14 #include "cifspdu.h"
15 #include "cifsglob.h"
16 #include "cifsproto.h"
17 #include "cifs_debug.h"
18 #include "cifs_fs_sb.h"
19 #include "cifs_unicode.h"
20 #include "cifs_ioctl.h"
21 
22 #define MAX_EA_VALUE_SIZE CIFSMaxBufSize
23 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
24 #define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
25 #define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
26 #define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
27 #define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
28 /*
29  * Although these three are just aliases for the above, need to move away from
30  * confusing users and using the 20+ year old term 'cifs' when it is no longer
31  * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
32  */
33 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
34 #define SMB3_XATTR_CIFS_NTSD_SACL "system.smb3_ntsd_sacl" /* SACL only */
35 #define SMB3_XATTR_CIFS_NTSD_OWNER "system.smb3_ntsd_owner" /* owner only */
36 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
37 #define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
38 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
39 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
40 /* BB need to add server (Samba e.g) support for security and trusted prefix */
41 
42 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
43 	XATTR_CIFS_NTSD_SACL, XATTR_CIFS_NTSD_OWNER,
44 	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
45 
46 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
47 			   struct inode *inode, const char *full_path,
48 			   const void *value, size_t size)
49 {
50 	ssize_t rc = -EOPNOTSUPP;
51 	__u32 *pattrib = (__u32 *)value;
52 	__u32 attrib;
53 	FILE_BASIC_INFO info_buf;
54 
55 	if ((value == NULL) || (size != sizeof(__u32)))
56 		return -ERANGE;
57 
58 	memset(&info_buf, 0, sizeof(info_buf));
59 	attrib = *pattrib;
60 	info_buf.Attributes = cpu_to_le32(attrib);
61 	if (pTcon->ses->server->ops->set_file_info)
62 		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
63 				&info_buf, xid);
64 	if (rc == 0)
65 		CIFS_I(inode)->cifsAttrs = attrib;
66 
67 	return rc;
68 }
69 
70 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
71 				  struct inode *inode, const char *full_path,
72 				  const void *value, size_t size)
73 {
74 	ssize_t rc = -EOPNOTSUPP;
75 	__u64 *pcreation_time = (__u64 *)value;
76 	__u64 creation_time;
77 	FILE_BASIC_INFO info_buf;
78 
79 	if ((value == NULL) || (size != sizeof(__u64)))
80 		return -ERANGE;
81 
82 	memset(&info_buf, 0, sizeof(info_buf));
83 	creation_time = *pcreation_time;
84 	info_buf.CreationTime = cpu_to_le64(creation_time);
85 	if (pTcon->ses->server->ops->set_file_info)
86 		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
87 				&info_buf, xid);
88 	if (rc == 0)
89 		CIFS_I(inode)->createtime = creation_time;
90 
91 	return rc;
92 }
93 
94 static int cifs_xattr_set(const struct xattr_handler *handler,
95 			  struct mnt_idmap *idmap,
96 			  struct dentry *dentry, struct inode *inode,
97 			  const char *name, const void *value,
98 			  size_t size, int flags)
99 {
100 	int rc = -EOPNOTSUPP;
101 	unsigned int xid;
102 	struct super_block *sb = dentry->d_sb;
103 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
104 	struct tcon_link *tlink;
105 	struct cifs_tcon *pTcon;
106 	const char *full_path;
107 	void *page;
108 
109 	tlink = cifs_sb_tlink(cifs_sb);
110 	if (IS_ERR(tlink))
111 		return PTR_ERR(tlink);
112 	pTcon = tlink_tcon(tlink);
113 
114 	xid = get_xid();
115 	page = alloc_dentry_path();
116 
117 	full_path = build_path_from_dentry(dentry, page);
118 	if (IS_ERR(full_path)) {
119 		rc = PTR_ERR(full_path);
120 		goto out;
121 	}
122 	/* return dos attributes as pseudo xattr */
123 	/* return alt name if available as pseudo attr */
124 
125 	/* if proc/fs/cifs/streamstoxattr is set then
126 		search server for EAs or streams to
127 		returns as xattrs */
128 	if (size > MAX_EA_VALUE_SIZE) {
129 		cifs_dbg(FYI, "size of EA value too large\n");
130 		rc = -EOPNOTSUPP;
131 		goto out;
132 	}
133 
134 	switch (handler->flags) {
135 	case XATTR_USER:
136 		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
137 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
138 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
139 			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
140 					value, size);
141 			if (rc == 0) /* force revalidate of the inode */
142 				CIFS_I(inode)->time = 0;
143 			break;
144 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
145 			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
146 			rc = cifs_creation_time_set(xid, pTcon, inode,
147 					full_path, value, size);
148 			if (rc == 0) /* force revalidate of the inode */
149 				CIFS_I(inode)->time = 0;
150 			break;
151 		}
152 
153 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
154 			goto out;
155 
156 		if (pTcon->ses->server->ops->set_EA) {
157 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
158 				full_path, name, value, (__u16)size,
159 				cifs_sb->local_nls, cifs_sb);
160 			if (rc == 0)
161 				inode_set_ctime_current(inode);
162 		}
163 		break;
164 
165 	case XATTR_CIFS_ACL:
166 	case XATTR_CIFS_NTSD_SACL:
167 	case XATTR_CIFS_NTSD_OWNER:
168 	case XATTR_CIFS_NTSD:
169 	case XATTR_CIFS_NTSD_FULL: {
170 		struct smb_ntsd *pacl;
171 
172 		if (!value)
173 			goto out;
174 		pacl = kmalloc(size, GFP_KERNEL);
175 		if (!pacl) {
176 			rc = -ENOMEM;
177 		} else {
178 			memcpy(pacl, value, size);
179 			if (pTcon->ses->server->ops->set_acl) {
180 				int aclflags = 0;
181 
182 				switch (handler->flags) {
183 				case XATTR_CIFS_NTSD_FULL:
184 					aclflags = (CIFS_ACL_OWNER |
185 						    CIFS_ACL_GROUP |
186 						    CIFS_ACL_DACL |
187 						    CIFS_ACL_SACL);
188 					break;
189 				case XATTR_CIFS_NTSD:
190 					aclflags = (CIFS_ACL_OWNER |
191 						    CIFS_ACL_GROUP |
192 						    CIFS_ACL_DACL);
193 					break;
194 				case XATTR_CIFS_NTSD_OWNER:
195 					aclflags = (CIFS_ACL_OWNER |
196 						    CIFS_ACL_GROUP);
197 					break;
198 				case XATTR_CIFS_NTSD_SACL:
199 					aclflags = CIFS_ACL_SACL;
200 					break;
201 				case XATTR_CIFS_ACL:
202 				default:
203 					aclflags = CIFS_ACL_DACL;
204 				}
205 
206 				rc = pTcon->ses->server->ops->set_acl(pacl,
207 					size, inode, full_path, aclflags);
208 			} else {
209 				rc = -EOPNOTSUPP;
210 			}
211 			if (rc == 0) /* force revalidate of the inode */
212 				CIFS_I(inode)->time = 0;
213 			kfree(pacl);
214 		}
215 		break;
216 	}
217 	}
218 
219 out:
220 	free_dentry_path(page);
221 	free_xid(xid);
222 	cifs_put_tlink(tlink);
223 	return rc;
224 }
225 
226 static int cifs_attrib_get(struct dentry *dentry,
227 			   struct inode *inode, void *value,
228 			   size_t size)
229 {
230 	ssize_t rc;
231 	__u32 *pattribute;
232 
233 	rc = cifs_revalidate_dentry_attr(dentry);
234 
235 	if (rc)
236 		return rc;
237 
238 	if ((value == NULL) || (size == 0))
239 		return sizeof(__u32);
240 	else if (size < sizeof(__u32))
241 		return -ERANGE;
242 
243 	/* return dos attributes as pseudo xattr */
244 	pattribute = (__u32 *)value;
245 	*pattribute = CIFS_I(inode)->cifsAttrs;
246 
247 	return sizeof(__u32);
248 }
249 
250 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
251 				  void *value, size_t size)
252 {
253 	ssize_t rc;
254 	__u64 *pcreatetime;
255 
256 	rc = cifs_revalidate_dentry_attr(dentry);
257 	if (rc)
258 		return rc;
259 
260 	if ((value == NULL) || (size == 0))
261 		return sizeof(__u64);
262 	else if (size < sizeof(__u64))
263 		return -ERANGE;
264 
265 	/* return dos attributes as pseudo xattr */
266 	pcreatetime = (__u64 *)value;
267 	*pcreatetime = CIFS_I(inode)->createtime;
268 	return sizeof(__u64);
269 }
270 
271 
272 static int cifs_xattr_get(const struct xattr_handler *handler,
273 			  struct dentry *dentry, struct inode *inode,
274 			  const char *name, void *value, size_t size)
275 {
276 	ssize_t rc = -EOPNOTSUPP;
277 	unsigned int xid;
278 	struct super_block *sb = dentry->d_sb;
279 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
280 	struct tcon_link *tlink;
281 	struct cifs_tcon *pTcon;
282 	const char *full_path;
283 	void *page;
284 
285 	tlink = cifs_sb_tlink(cifs_sb);
286 	if (IS_ERR(tlink))
287 		return PTR_ERR(tlink);
288 	pTcon = tlink_tcon(tlink);
289 
290 	xid = get_xid();
291 	page = alloc_dentry_path();
292 
293 	full_path = build_path_from_dentry(dentry, page);
294 	if (IS_ERR(full_path)) {
295 		rc = PTR_ERR(full_path);
296 		goto out;
297 	}
298 
299 	/* return alt name if available as pseudo attr */
300 	switch (handler->flags) {
301 	case XATTR_USER:
302 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
303 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
304 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
305 			rc = cifs_attrib_get(dentry, inode, value, size);
306 			break;
307 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
308 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
309 			rc = cifs_creation_time_get(dentry, inode, value, size);
310 			break;
311 		}
312 
313 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
314 			goto out;
315 
316 		if (pTcon->ses->server->ops->query_all_EAs)
317 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
318 				full_path, name, value, size, cifs_sb);
319 		break;
320 
321 	case XATTR_CIFS_ACL:
322 	case XATTR_CIFS_NTSD_SACL:
323 	case XATTR_CIFS_NTSD_OWNER:
324 	case XATTR_CIFS_NTSD:
325 	case XATTR_CIFS_NTSD_FULL: {
326 		/*
327 		 * fetch owner, DACL, and SACL if asked for full descriptor,
328 		 * fetch owner and DACL otherwise
329 		 */
330 		u32 acllen, extra_info;
331 		struct smb_ntsd *pacl;
332 
333 		if (pTcon->ses->server->ops->get_acl == NULL)
334 			goto out; /* rc already EOPNOTSUPP */
335 
336 		switch (handler->flags) {
337 		case XATTR_CIFS_NTSD_FULL:
338 			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO | SACL_SECINFO;
339 			break;
340 		case XATTR_CIFS_NTSD:
341 			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
342 			break;
343 		case XATTR_CIFS_NTSD_OWNER:
344 			extra_info = OWNER_SECINFO | GROUP_SECINFO;
345 			break;
346 		case XATTR_CIFS_NTSD_SACL:
347 			extra_info = SACL_SECINFO;
348 			break;
349 		case XATTR_CIFS_ACL:
350 		default:
351 			extra_info = DACL_SECINFO;
352 			break;
353 		}
354 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
355 				inode, full_path, &acllen, extra_info);
356 		if (IS_ERR(pacl)) {
357 			rc = PTR_ERR(pacl);
358 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
359 				 __func__, rc);
360 		} else {
361 			if (value) {
362 				if (acllen > size)
363 					acllen = -ERANGE;
364 				else
365 					memcpy(value, pacl, acllen);
366 			}
367 			rc = acllen;
368 			kfree(pacl);
369 		}
370 		break;
371 	}
372 	}
373 
374 	/* We could add an additional check for streams ie
375 	    if proc/fs/cifs/streamstoxattr is set then
376 		search server for EAs or streams to
377 		returns as xattrs */
378 
379 	if (rc == -EINVAL)
380 		rc = -EOPNOTSUPP;
381 
382 out:
383 	free_dentry_path(page);
384 	free_xid(xid);
385 	cifs_put_tlink(tlink);
386 	return rc;
387 }
388 
389 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
390 {
391 	ssize_t rc = -EOPNOTSUPP;
392 	unsigned int xid;
393 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
394 	struct tcon_link *tlink;
395 	struct cifs_tcon *pTcon;
396 	const char *full_path;
397 	void *page;
398 
399 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
400 		return -EIO;
401 
402 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
403 		return -EOPNOTSUPP;
404 
405 	tlink = cifs_sb_tlink(cifs_sb);
406 	if (IS_ERR(tlink))
407 		return PTR_ERR(tlink);
408 	pTcon = tlink_tcon(tlink);
409 
410 	xid = get_xid();
411 	page = alloc_dentry_path();
412 
413 	full_path = build_path_from_dentry(direntry, page);
414 	if (IS_ERR(full_path)) {
415 		rc = PTR_ERR(full_path);
416 		goto list_ea_exit;
417 	}
418 	/* return dos attributes as pseudo xattr */
419 	/* return alt name if available as pseudo attr */
420 
421 	/* if proc/fs/cifs/streamstoxattr is set then
422 		search server for EAs or streams to
423 		returns as xattrs */
424 
425 	if (pTcon->ses->server->ops->query_all_EAs)
426 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
427 				full_path, NULL, data, buf_size, cifs_sb);
428 list_ea_exit:
429 	free_dentry_path(page);
430 	free_xid(xid);
431 	cifs_put_tlink(tlink);
432 	return rc;
433 }
434 
435 static const struct xattr_handler cifs_user_xattr_handler = {
436 	.prefix = XATTR_USER_PREFIX,
437 	.flags = XATTR_USER,
438 	.get = cifs_xattr_get,
439 	.set = cifs_xattr_set,
440 };
441 
442 /* os2.* attributes are treated like user.* attributes */
443 static const struct xattr_handler cifs_os2_xattr_handler = {
444 	.prefix = XATTR_OS2_PREFIX,
445 	.flags = XATTR_USER,
446 	.get = cifs_xattr_get,
447 	.set = cifs_xattr_set,
448 };
449 
450 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
451 	.name = CIFS_XATTR_CIFS_ACL,
452 	.flags = XATTR_CIFS_ACL,
453 	.get = cifs_xattr_get,
454 	.set = cifs_xattr_set,
455 };
456 
457 /*
458  * Although this is just an alias for the above, need to move away from
459  * confusing users and using the 20 year old term 'cifs' when it is no
460  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
461  * SMB3 and later are highly secure.
462  */
463 static const struct xattr_handler smb3_acl_xattr_handler = {
464 	.name = SMB3_XATTR_CIFS_ACL,
465 	.flags = XATTR_CIFS_ACL,
466 	.get = cifs_xattr_get,
467 	.set = cifs_xattr_set,
468 };
469 
470 static const struct xattr_handler smb3_ntsd_sacl_xattr_handler = {
471 	.name = SMB3_XATTR_CIFS_NTSD_SACL,
472 	.flags = XATTR_CIFS_NTSD_SACL,
473 	.get = cifs_xattr_get,
474 	.set = cifs_xattr_set,
475 };
476 
477 static const struct xattr_handler smb3_ntsd_owner_xattr_handler = {
478 	.name = SMB3_XATTR_CIFS_NTSD_OWNER,
479 	.flags = XATTR_CIFS_NTSD_OWNER,
480 	.get = cifs_xattr_get,
481 	.set = cifs_xattr_set,
482 };
483 
484 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
485 	.name = CIFS_XATTR_CIFS_NTSD,
486 	.flags = XATTR_CIFS_NTSD,
487 	.get = cifs_xattr_get,
488 	.set = cifs_xattr_set,
489 };
490 
491 /*
492  * Although this is just an alias for the above, need to move away from
493  * confusing users and using the 20 year old term 'cifs' when it is no
494  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
495  * SMB3 and later are highly secure.
496  */
497 static const struct xattr_handler smb3_ntsd_xattr_handler = {
498 	.name = SMB3_XATTR_CIFS_NTSD,
499 	.flags = XATTR_CIFS_NTSD,
500 	.get = cifs_xattr_get,
501 	.set = cifs_xattr_set,
502 };
503 
504 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
505 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
506 	.flags = XATTR_CIFS_NTSD_FULL,
507 	.get = cifs_xattr_get,
508 	.set = cifs_xattr_set,
509 };
510 
511 /*
512  * Although this is just an alias for the above, need to move away from
513  * confusing users and using the 20 year old term 'cifs' when it is no
514  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
515  * SMB3 and later are highly secure.
516  */
517 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
518 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
519 	.flags = XATTR_CIFS_NTSD_FULL,
520 	.get = cifs_xattr_get,
521 	.set = cifs_xattr_set,
522 };
523 
524 const struct xattr_handler * const cifs_xattr_handlers[] = {
525 	&cifs_user_xattr_handler,
526 	&cifs_os2_xattr_handler,
527 	&cifs_cifs_acl_xattr_handler,
528 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
529 	&smb3_ntsd_sacl_xattr_handler,
530 	&smb3_ntsd_owner_xattr_handler,
531 	&cifs_cifs_ntsd_xattr_handler,
532 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
533 	&cifs_cifs_ntsd_full_xattr_handler,
534 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
535 	NULL
536 };
537