xref: /linux/fs/smb/client/xattr.c (revision 9f867ba24d3665d9ac9d9ef1f51844eb4479b291)
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 
cifs_attrib_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)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 
cifs_creation_time_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)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 
cifs_xattr_set(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)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 				rc = 0;
182 
183 				switch (handler->flags) {
184 				case XATTR_CIFS_NTSD_FULL:
185 					aclflags = (CIFS_ACL_OWNER |
186 						    CIFS_ACL_GROUP |
187 						    CIFS_ACL_DACL |
188 						    CIFS_ACL_SACL);
189 					break;
190 				case XATTR_CIFS_NTSD:
191 					aclflags = (CIFS_ACL_OWNER |
192 						    CIFS_ACL_GROUP |
193 						    CIFS_ACL_DACL);
194 					break;
195 				case XATTR_CIFS_NTSD_OWNER:
196 					aclflags = (CIFS_ACL_OWNER |
197 						    CIFS_ACL_GROUP);
198 					break;
199 				case XATTR_CIFS_NTSD_SACL:
200 					aclflags = CIFS_ACL_SACL;
201 					break;
202 				case XATTR_CIFS_ACL:
203 				default:
204 					aclflags = CIFS_ACL_DACL;
205 				}
206 
207 				rc = pTcon->ses->server->ops->set_acl(pacl,
208 					size, inode, full_path, aclflags);
209 			} else {
210 				rc = -EOPNOTSUPP;
211 			}
212 			if (rc == 0) /* force revalidate of the inode */
213 				CIFS_I(inode)->time = 0;
214 			kfree(pacl);
215 		}
216 		break;
217 	}
218 	}
219 
220 out:
221 	free_dentry_path(page);
222 	free_xid(xid);
223 	cifs_put_tlink(tlink);
224 	return rc;
225 }
226 
cifs_attrib_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)227 static int cifs_attrib_get(struct dentry *dentry,
228 			   struct inode *inode, void *value,
229 			   size_t size)
230 {
231 	ssize_t rc;
232 	__u32 *pattribute;
233 
234 	rc = cifs_revalidate_dentry_attr(dentry);
235 
236 	if (rc)
237 		return rc;
238 
239 	if ((value == NULL) || (size == 0))
240 		return sizeof(__u32);
241 	else if (size < sizeof(__u32))
242 		return -ERANGE;
243 
244 	/* return dos attributes as pseudo xattr */
245 	pattribute = (__u32 *)value;
246 	*pattribute = CIFS_I(inode)->cifsAttrs;
247 
248 	return sizeof(__u32);
249 }
250 
cifs_creation_time_get(struct dentry * dentry,struct inode * inode,void * value,size_t size)251 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
252 				  void *value, size_t size)
253 {
254 	ssize_t rc;
255 	__u64 *pcreatetime;
256 
257 	rc = cifs_revalidate_dentry_attr(dentry);
258 	if (rc)
259 		return rc;
260 
261 	if ((value == NULL) || (size == 0))
262 		return sizeof(__u64);
263 	else if (size < sizeof(__u64))
264 		return -ERANGE;
265 
266 	/* return dos attributes as pseudo xattr */
267 	pcreatetime = (__u64 *)value;
268 	*pcreatetime = CIFS_I(inode)->createtime;
269 	return sizeof(__u64);
270 }
271 
272 
cifs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * name,void * value,size_t size)273 static int cifs_xattr_get(const struct xattr_handler *handler,
274 			  struct dentry *dentry, struct inode *inode,
275 			  const char *name, void *value, size_t size)
276 {
277 	ssize_t rc = -EOPNOTSUPP;
278 	unsigned int xid;
279 	struct super_block *sb = dentry->d_sb;
280 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
281 	struct tcon_link *tlink;
282 	struct cifs_tcon *pTcon;
283 	const char *full_path;
284 	void *page;
285 
286 	tlink = cifs_sb_tlink(cifs_sb);
287 	if (IS_ERR(tlink))
288 		return PTR_ERR(tlink);
289 	pTcon = tlink_tcon(tlink);
290 
291 	xid = get_xid();
292 	page = alloc_dentry_path();
293 
294 	full_path = build_path_from_dentry(dentry, page);
295 	if (IS_ERR(full_path)) {
296 		rc = PTR_ERR(full_path);
297 		goto out;
298 	}
299 
300 	/* return alt name if available as pseudo attr */
301 	switch (handler->flags) {
302 	case XATTR_USER:
303 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
304 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
305 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
306 			rc = cifs_attrib_get(dentry, inode, value, size);
307 			break;
308 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
309 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
310 			rc = cifs_creation_time_get(dentry, inode, value, size);
311 			break;
312 		}
313 
314 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
315 			goto out;
316 
317 		if (pTcon->ses->server->ops->query_all_EAs)
318 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
319 				full_path, name, value, size, cifs_sb);
320 		break;
321 
322 	case XATTR_CIFS_ACL:
323 	case XATTR_CIFS_NTSD_SACL:
324 	case XATTR_CIFS_NTSD_OWNER:
325 	case XATTR_CIFS_NTSD:
326 	case XATTR_CIFS_NTSD_FULL: {
327 		/*
328 		 * fetch owner, DACL, and SACL if asked for full descriptor,
329 		 * fetch owner and DACL otherwise
330 		 */
331 		u32 acllen, extra_info;
332 		struct smb_ntsd *pacl;
333 
334 		if (pTcon->ses->server->ops->get_acl == NULL)
335 			goto out; /* rc already EOPNOTSUPP */
336 
337 		switch (handler->flags) {
338 		case XATTR_CIFS_NTSD_FULL:
339 			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO | SACL_SECINFO;
340 			break;
341 		case XATTR_CIFS_NTSD:
342 			extra_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
343 			break;
344 		case XATTR_CIFS_NTSD_OWNER:
345 			extra_info = OWNER_SECINFO | GROUP_SECINFO;
346 			break;
347 		case XATTR_CIFS_NTSD_SACL:
348 			extra_info = SACL_SECINFO;
349 			break;
350 		case XATTR_CIFS_ACL:
351 		default:
352 			extra_info = DACL_SECINFO;
353 			break;
354 		}
355 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
356 				inode, full_path, &acllen, extra_info);
357 		if (IS_ERR(pacl)) {
358 			rc = PTR_ERR(pacl);
359 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
360 				 __func__, rc);
361 		} else {
362 			if (value) {
363 				if (acllen > size)
364 					acllen = -ERANGE;
365 				else
366 					memcpy(value, pacl, acllen);
367 			}
368 			rc = acllen;
369 			kfree(pacl);
370 		}
371 		break;
372 	}
373 	}
374 
375 	/* We could add an additional check for streams ie
376 	    if proc/fs/cifs/streamstoxattr is set then
377 		search server for EAs or streams to
378 		returns as xattrs */
379 
380 	if (rc == -EINVAL)
381 		rc = -EOPNOTSUPP;
382 
383 out:
384 	free_dentry_path(page);
385 	free_xid(xid);
386 	cifs_put_tlink(tlink);
387 	return rc;
388 }
389 
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)390 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
391 {
392 	ssize_t rc = -EOPNOTSUPP;
393 	unsigned int xid;
394 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
395 	struct tcon_link *tlink;
396 	struct cifs_tcon *pTcon;
397 	const char *full_path;
398 	void *page;
399 
400 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
401 		return -EIO;
402 
403 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
404 		return -EOPNOTSUPP;
405 
406 	tlink = cifs_sb_tlink(cifs_sb);
407 	if (IS_ERR(tlink))
408 		return PTR_ERR(tlink);
409 	pTcon = tlink_tcon(tlink);
410 
411 	xid = get_xid();
412 	page = alloc_dentry_path();
413 
414 	full_path = build_path_from_dentry(direntry, page);
415 	if (IS_ERR(full_path)) {
416 		rc = PTR_ERR(full_path);
417 		goto list_ea_exit;
418 	}
419 	/* return dos attributes as pseudo xattr */
420 	/* return alt name if available as pseudo attr */
421 
422 	/* if proc/fs/cifs/streamstoxattr is set then
423 		search server for EAs or streams to
424 		returns as xattrs */
425 
426 	if (pTcon->ses->server->ops->query_all_EAs)
427 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
428 				full_path, NULL, data, buf_size, cifs_sb);
429 list_ea_exit:
430 	free_dentry_path(page);
431 	free_xid(xid);
432 	cifs_put_tlink(tlink);
433 	return rc;
434 }
435 
436 static const struct xattr_handler cifs_user_xattr_handler = {
437 	.prefix = XATTR_USER_PREFIX,
438 	.flags = XATTR_USER,
439 	.get = cifs_xattr_get,
440 	.set = cifs_xattr_set,
441 };
442 
443 /* os2.* attributes are treated like user.* attributes */
444 static const struct xattr_handler cifs_os2_xattr_handler = {
445 	.prefix = XATTR_OS2_PREFIX,
446 	.flags = XATTR_USER,
447 	.get = cifs_xattr_get,
448 	.set = cifs_xattr_set,
449 };
450 
451 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
452 	.name = CIFS_XATTR_CIFS_ACL,
453 	.flags = XATTR_CIFS_ACL,
454 	.get = cifs_xattr_get,
455 	.set = cifs_xattr_set,
456 };
457 
458 /*
459  * Although this is just an alias for the above, need to move away from
460  * confusing users and using the 20 year old term 'cifs' when it is no
461  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
462  * SMB3 and later are highly secure.
463  */
464 static const struct xattr_handler smb3_acl_xattr_handler = {
465 	.name = SMB3_XATTR_CIFS_ACL,
466 	.flags = XATTR_CIFS_ACL,
467 	.get = cifs_xattr_get,
468 	.set = cifs_xattr_set,
469 };
470 
471 static const struct xattr_handler smb3_ntsd_sacl_xattr_handler = {
472 	.name = SMB3_XATTR_CIFS_NTSD_SACL,
473 	.flags = XATTR_CIFS_NTSD_SACL,
474 	.get = cifs_xattr_get,
475 	.set = cifs_xattr_set,
476 };
477 
478 static const struct xattr_handler smb3_ntsd_owner_xattr_handler = {
479 	.name = SMB3_XATTR_CIFS_NTSD_OWNER,
480 	.flags = XATTR_CIFS_NTSD_OWNER,
481 	.get = cifs_xattr_get,
482 	.set = cifs_xattr_set,
483 };
484 
485 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
486 	.name = CIFS_XATTR_CIFS_NTSD,
487 	.flags = XATTR_CIFS_NTSD,
488 	.get = cifs_xattr_get,
489 	.set = cifs_xattr_set,
490 };
491 
492 /*
493  * Although this is just an alias for the above, need to move away from
494  * confusing users and using the 20 year old term 'cifs' when it is no
495  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
496  * SMB3 and later are highly secure.
497  */
498 static const struct xattr_handler smb3_ntsd_xattr_handler = {
499 	.name = SMB3_XATTR_CIFS_NTSD,
500 	.flags = XATTR_CIFS_NTSD,
501 	.get = cifs_xattr_get,
502 	.set = cifs_xattr_set,
503 };
504 
505 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
506 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
507 	.flags = XATTR_CIFS_NTSD_FULL,
508 	.get = cifs_xattr_get,
509 	.set = cifs_xattr_set,
510 };
511 
512 /*
513  * Although this is just an alias for the above, need to move away from
514  * confusing users and using the 20 year old term 'cifs' when it is no
515  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
516  * SMB3 and later are highly secure.
517  */
518 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
519 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
520 	.flags = XATTR_CIFS_NTSD_FULL,
521 	.get = cifs_xattr_get,
522 	.set = cifs_xattr_set,
523 };
524 
525 const struct xattr_handler * const cifs_xattr_handlers[] = {
526 	&cifs_user_xattr_handler,
527 	&cifs_os2_xattr_handler,
528 	&cifs_cifs_acl_xattr_handler,
529 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
530 	&smb3_ntsd_sacl_xattr_handler,
531 	&smb3_ntsd_owner_xattr_handler,
532 	&cifs_cifs_ntsd_xattr_handler,
533 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
534 	&cifs_cifs_ntsd_full_xattr_handler,
535 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
536 	NULL
537 };
538