xref: /linux/fs/smb/client/xattr.c (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
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 "system.smb3_ntsd" /* owner plus DACL */
35 #define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
36 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
37 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
38 /* BB need to add server (Samba e.g) support for security and trusted prefix */
39 
40 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
41 	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
42 
43 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
44 			   struct inode *inode, const char *full_path,
45 			   const void *value, size_t size)
46 {
47 	ssize_t rc = -EOPNOTSUPP;
48 	__u32 *pattrib = (__u32 *)value;
49 	__u32 attrib;
50 	FILE_BASIC_INFO info_buf;
51 
52 	if ((value == NULL) || (size != sizeof(__u32)))
53 		return -ERANGE;
54 
55 	memset(&info_buf, 0, sizeof(info_buf));
56 	attrib = *pattrib;
57 	info_buf.Attributes = cpu_to_le32(attrib);
58 	if (pTcon->ses->server->ops->set_file_info)
59 		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
60 				&info_buf, xid);
61 	if (rc == 0)
62 		CIFS_I(inode)->cifsAttrs = attrib;
63 
64 	return rc;
65 }
66 
67 static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
68 				  struct inode *inode, const char *full_path,
69 				  const void *value, size_t size)
70 {
71 	ssize_t rc = -EOPNOTSUPP;
72 	__u64 *pcreation_time = (__u64 *)value;
73 	__u64 creation_time;
74 	FILE_BASIC_INFO info_buf;
75 
76 	if ((value == NULL) || (size != sizeof(__u64)))
77 		return -ERANGE;
78 
79 	memset(&info_buf, 0, sizeof(info_buf));
80 	creation_time = *pcreation_time;
81 	info_buf.CreationTime = cpu_to_le64(creation_time);
82 	if (pTcon->ses->server->ops->set_file_info)
83 		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
84 				&info_buf, xid);
85 	if (rc == 0)
86 		CIFS_I(inode)->createtime = creation_time;
87 
88 	return rc;
89 }
90 
91 static int cifs_xattr_set(const struct xattr_handler *handler,
92 			  struct mnt_idmap *idmap,
93 			  struct dentry *dentry, struct inode *inode,
94 			  const char *name, const void *value,
95 			  size_t size, int flags)
96 {
97 	int rc = -EOPNOTSUPP;
98 	unsigned int xid;
99 	struct super_block *sb = dentry->d_sb;
100 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
101 	struct tcon_link *tlink;
102 	struct cifs_tcon *pTcon;
103 	const char *full_path;
104 	void *page;
105 
106 	tlink = cifs_sb_tlink(cifs_sb);
107 	if (IS_ERR(tlink))
108 		return PTR_ERR(tlink);
109 	pTcon = tlink_tcon(tlink);
110 
111 	xid = get_xid();
112 	page = alloc_dentry_path();
113 
114 	full_path = build_path_from_dentry(dentry, page);
115 	if (IS_ERR(full_path)) {
116 		rc = PTR_ERR(full_path);
117 		goto out;
118 	}
119 	/* return dos attributes as pseudo xattr */
120 	/* return alt name if available as pseudo attr */
121 
122 	/* if proc/fs/cifs/streamstoxattr is set then
123 		search server for EAs or streams to
124 		returns as xattrs */
125 	if (size > MAX_EA_VALUE_SIZE) {
126 		cifs_dbg(FYI, "size of EA value too large\n");
127 		rc = -EOPNOTSUPP;
128 		goto out;
129 	}
130 
131 	switch (handler->flags) {
132 	case XATTR_USER:
133 		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
134 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
135 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
136 			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
137 					value, size);
138 			if (rc == 0) /* force revalidate of the inode */
139 				CIFS_I(inode)->time = 0;
140 			break;
141 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
142 			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
143 			rc = cifs_creation_time_set(xid, pTcon, inode,
144 					full_path, value, size);
145 			if (rc == 0) /* force revalidate of the inode */
146 				CIFS_I(inode)->time = 0;
147 			break;
148 		}
149 
150 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
151 			goto out;
152 
153 		if (pTcon->ses->server->ops->set_EA)
154 			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
155 				full_path, name, value, (__u16)size,
156 				cifs_sb->local_nls, cifs_sb);
157 		break;
158 
159 	case XATTR_CIFS_ACL:
160 	case XATTR_CIFS_NTSD:
161 	case XATTR_CIFS_NTSD_FULL: {
162 		struct cifs_ntsd *pacl;
163 
164 		if (!value)
165 			goto out;
166 		pacl = kmalloc(size, GFP_KERNEL);
167 		if (!pacl) {
168 			rc = -ENOMEM;
169 		} else {
170 			memcpy(pacl, value, size);
171 			if (pTcon->ses->server->ops->set_acl) {
172 				int aclflags = 0;
173 				rc = 0;
174 
175 				switch (handler->flags) {
176 				case XATTR_CIFS_NTSD_FULL:
177 					aclflags = (CIFS_ACL_OWNER |
178 						    CIFS_ACL_GROUP |
179 						    CIFS_ACL_DACL |
180 						    CIFS_ACL_SACL);
181 					break;
182 				case XATTR_CIFS_NTSD:
183 					aclflags = (CIFS_ACL_OWNER |
184 						    CIFS_ACL_GROUP |
185 						    CIFS_ACL_DACL);
186 					break;
187 				case XATTR_CIFS_ACL:
188 				default:
189 					aclflags = CIFS_ACL_DACL;
190 				}
191 
192 				rc = pTcon->ses->server->ops->set_acl(pacl,
193 					size, inode, full_path, aclflags);
194 			} else {
195 				rc = -EOPNOTSUPP;
196 			}
197 			if (rc == 0) /* force revalidate of the inode */
198 				CIFS_I(inode)->time = 0;
199 			kfree(pacl);
200 		}
201 		break;
202 	}
203 	}
204 
205 out:
206 	free_dentry_path(page);
207 	free_xid(xid);
208 	cifs_put_tlink(tlink);
209 	return rc;
210 }
211 
212 static int cifs_attrib_get(struct dentry *dentry,
213 			   struct inode *inode, void *value,
214 			   size_t size)
215 {
216 	ssize_t rc;
217 	__u32 *pattribute;
218 
219 	rc = cifs_revalidate_dentry_attr(dentry);
220 
221 	if (rc)
222 		return rc;
223 
224 	if ((value == NULL) || (size == 0))
225 		return sizeof(__u32);
226 	else if (size < sizeof(__u32))
227 		return -ERANGE;
228 
229 	/* return dos attributes as pseudo xattr */
230 	pattribute = (__u32 *)value;
231 	*pattribute = CIFS_I(inode)->cifsAttrs;
232 
233 	return sizeof(__u32);
234 }
235 
236 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
237 				  void *value, size_t size)
238 {
239 	ssize_t rc;
240 	__u64 *pcreatetime;
241 
242 	rc = cifs_revalidate_dentry_attr(dentry);
243 	if (rc)
244 		return rc;
245 
246 	if ((value == NULL) || (size == 0))
247 		return sizeof(__u64);
248 	else if (size < sizeof(__u64))
249 		return -ERANGE;
250 
251 	/* return dos attributes as pseudo xattr */
252 	pcreatetime = (__u64 *)value;
253 	*pcreatetime = CIFS_I(inode)->createtime;
254 	return sizeof(__u64);
255 }
256 
257 
258 static int cifs_xattr_get(const struct xattr_handler *handler,
259 			  struct dentry *dentry, struct inode *inode,
260 			  const char *name, void *value, size_t size)
261 {
262 	ssize_t rc = -EOPNOTSUPP;
263 	unsigned int xid;
264 	struct super_block *sb = dentry->d_sb;
265 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
266 	struct tcon_link *tlink;
267 	struct cifs_tcon *pTcon;
268 	const char *full_path;
269 	void *page;
270 
271 	tlink = cifs_sb_tlink(cifs_sb);
272 	if (IS_ERR(tlink))
273 		return PTR_ERR(tlink);
274 	pTcon = tlink_tcon(tlink);
275 
276 	xid = get_xid();
277 	page = alloc_dentry_path();
278 
279 	full_path = build_path_from_dentry(dentry, page);
280 	if (IS_ERR(full_path)) {
281 		rc = PTR_ERR(full_path);
282 		goto out;
283 	}
284 
285 	/* return alt name if available as pseudo attr */
286 	switch (handler->flags) {
287 	case XATTR_USER:
288 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
289 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
290 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
291 			rc = cifs_attrib_get(dentry, inode, value, size);
292 			break;
293 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
294 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
295 			rc = cifs_creation_time_get(dentry, inode, value, size);
296 			break;
297 		}
298 
299 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
300 			goto out;
301 
302 		if (pTcon->ses->server->ops->query_all_EAs)
303 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
304 				full_path, name, value, size, cifs_sb);
305 		break;
306 
307 	case XATTR_CIFS_ACL:
308 	case XATTR_CIFS_NTSD:
309 	case XATTR_CIFS_NTSD_FULL: {
310 		/*
311 		 * fetch owner, DACL, and SACL if asked for full descriptor,
312 		 * fetch owner and DACL otherwise
313 		 */
314 		u32 acllen, extra_info;
315 		struct cifs_ntsd *pacl;
316 
317 		if (pTcon->ses->server->ops->get_acl == NULL)
318 			goto out; /* rc already EOPNOTSUPP */
319 
320 		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
321 			extra_info = SACL_SECINFO;
322 		} else {
323 			extra_info = 0;
324 		}
325 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
326 				inode, full_path, &acllen, extra_info);
327 		if (IS_ERR(pacl)) {
328 			rc = PTR_ERR(pacl);
329 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
330 				 __func__, rc);
331 		} else {
332 			if (value) {
333 				if (acllen > size)
334 					acllen = -ERANGE;
335 				else
336 					memcpy(value, pacl, acllen);
337 			}
338 			rc = acllen;
339 			kfree(pacl);
340 		}
341 		break;
342 	}
343 	}
344 
345 	/* We could add an additional check for streams ie
346 	    if proc/fs/cifs/streamstoxattr is set then
347 		search server for EAs or streams to
348 		returns as xattrs */
349 
350 	if (rc == -EINVAL)
351 		rc = -EOPNOTSUPP;
352 
353 out:
354 	free_dentry_path(page);
355 	free_xid(xid);
356 	cifs_put_tlink(tlink);
357 	return rc;
358 }
359 
360 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
361 {
362 	ssize_t rc = -EOPNOTSUPP;
363 	unsigned int xid;
364 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
365 	struct tcon_link *tlink;
366 	struct cifs_tcon *pTcon;
367 	const char *full_path;
368 	void *page;
369 
370 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
371 		return -EIO;
372 
373 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
374 		return -EOPNOTSUPP;
375 
376 	tlink = cifs_sb_tlink(cifs_sb);
377 	if (IS_ERR(tlink))
378 		return PTR_ERR(tlink);
379 	pTcon = tlink_tcon(tlink);
380 
381 	xid = get_xid();
382 	page = alloc_dentry_path();
383 
384 	full_path = build_path_from_dentry(direntry, page);
385 	if (IS_ERR(full_path)) {
386 		rc = PTR_ERR(full_path);
387 		goto list_ea_exit;
388 	}
389 	/* return dos attributes as pseudo xattr */
390 	/* return alt name if available as pseudo attr */
391 
392 	/* if proc/fs/cifs/streamstoxattr is set then
393 		search server for EAs or streams to
394 		returns as xattrs */
395 
396 	if (pTcon->ses->server->ops->query_all_EAs)
397 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
398 				full_path, NULL, data, buf_size, cifs_sb);
399 list_ea_exit:
400 	free_dentry_path(page);
401 	free_xid(xid);
402 	cifs_put_tlink(tlink);
403 	return rc;
404 }
405 
406 static const struct xattr_handler cifs_user_xattr_handler = {
407 	.prefix = XATTR_USER_PREFIX,
408 	.flags = XATTR_USER,
409 	.get = cifs_xattr_get,
410 	.set = cifs_xattr_set,
411 };
412 
413 /* os2.* attributes are treated like user.* attributes */
414 static const struct xattr_handler cifs_os2_xattr_handler = {
415 	.prefix = XATTR_OS2_PREFIX,
416 	.flags = XATTR_USER,
417 	.get = cifs_xattr_get,
418 	.set = cifs_xattr_set,
419 };
420 
421 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
422 	.name = CIFS_XATTR_CIFS_ACL,
423 	.flags = XATTR_CIFS_ACL,
424 	.get = cifs_xattr_get,
425 	.set = cifs_xattr_set,
426 };
427 
428 /*
429  * Although this is just an alias for the above, need to move away from
430  * confusing users and using the 20 year old term 'cifs' when it is no
431  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
432  * SMB3 and later are highly secure.
433  */
434 static const struct xattr_handler smb3_acl_xattr_handler = {
435 	.name = SMB3_XATTR_CIFS_ACL,
436 	.flags = XATTR_CIFS_ACL,
437 	.get = cifs_xattr_get,
438 	.set = cifs_xattr_set,
439 };
440 
441 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
442 	.name = CIFS_XATTR_CIFS_NTSD,
443 	.flags = XATTR_CIFS_NTSD,
444 	.get = cifs_xattr_get,
445 	.set = cifs_xattr_set,
446 };
447 
448 /*
449  * Although this is just an alias for the above, need to move away from
450  * confusing users and using the 20 year old term 'cifs' when it is no
451  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
452  * SMB3 and later are highly secure.
453  */
454 static const struct xattr_handler smb3_ntsd_xattr_handler = {
455 	.name = SMB3_XATTR_CIFS_NTSD,
456 	.flags = XATTR_CIFS_NTSD,
457 	.get = cifs_xattr_get,
458 	.set = cifs_xattr_set,
459 };
460 
461 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
462 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
463 	.flags = XATTR_CIFS_NTSD_FULL,
464 	.get = cifs_xattr_get,
465 	.set = cifs_xattr_set,
466 };
467 
468 /*
469  * Although this is just an alias for the above, need to move away from
470  * confusing users and using the 20 year old term 'cifs' when it is no
471  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
472  * SMB3 and later are highly secure.
473  */
474 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
475 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
476 	.flags = XATTR_CIFS_NTSD_FULL,
477 	.get = cifs_xattr_get,
478 	.set = cifs_xattr_set,
479 };
480 
481 const struct xattr_handler *cifs_xattr_handlers[] = {
482 	&cifs_user_xattr_handler,
483 	&cifs_os2_xattr_handler,
484 	&cifs_cifs_acl_xattr_handler,
485 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
486 	&cifs_cifs_ntsd_xattr_handler,
487 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
488 	&cifs_cifs_ntsd_full_xattr_handler,
489 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
490 	NULL
491 };
492