xref: /openbmc/linux/fs/smb/client/xattr.c (revision 9aa2cba7)
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 			if (rc == 0)
158 				inode_set_ctime_current(inode);
159 		}
160 		break;
161 
162 	case XATTR_CIFS_ACL:
163 	case XATTR_CIFS_NTSD:
164 	case XATTR_CIFS_NTSD_FULL: {
165 		struct cifs_ntsd *pacl;
166 
167 		if (!value)
168 			goto out;
169 		pacl = kmalloc(size, GFP_KERNEL);
170 		if (!pacl) {
171 			rc = -ENOMEM;
172 		} else {
173 			memcpy(pacl, value, size);
174 			if (pTcon->ses->server->ops->set_acl) {
175 				int aclflags = 0;
176 				rc = 0;
177 
178 				switch (handler->flags) {
179 				case XATTR_CIFS_NTSD_FULL:
180 					aclflags = (CIFS_ACL_OWNER |
181 						    CIFS_ACL_GROUP |
182 						    CIFS_ACL_DACL |
183 						    CIFS_ACL_SACL);
184 					break;
185 				case XATTR_CIFS_NTSD:
186 					aclflags = (CIFS_ACL_OWNER |
187 						    CIFS_ACL_GROUP |
188 						    CIFS_ACL_DACL);
189 					break;
190 				case XATTR_CIFS_ACL:
191 				default:
192 					aclflags = CIFS_ACL_DACL;
193 				}
194 
195 				rc = pTcon->ses->server->ops->set_acl(pacl,
196 					size, inode, full_path, aclflags);
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 
208 out:
209 	free_dentry_path(page);
210 	free_xid(xid);
211 	cifs_put_tlink(tlink);
212 	return rc;
213 }
214 
215 static int cifs_attrib_get(struct dentry *dentry,
216 			   struct inode *inode, void *value,
217 			   size_t size)
218 {
219 	ssize_t rc;
220 	__u32 *pattribute;
221 
222 	rc = cifs_revalidate_dentry_attr(dentry);
223 
224 	if (rc)
225 		return rc;
226 
227 	if ((value == NULL) || (size == 0))
228 		return sizeof(__u32);
229 	else if (size < sizeof(__u32))
230 		return -ERANGE;
231 
232 	/* return dos attributes as pseudo xattr */
233 	pattribute = (__u32 *)value;
234 	*pattribute = CIFS_I(inode)->cifsAttrs;
235 
236 	return sizeof(__u32);
237 }
238 
239 static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
240 				  void *value, size_t size)
241 {
242 	ssize_t rc;
243 	__u64 *pcreatetime;
244 
245 	rc = cifs_revalidate_dentry_attr(dentry);
246 	if (rc)
247 		return rc;
248 
249 	if ((value == NULL) || (size == 0))
250 		return sizeof(__u64);
251 	else if (size < sizeof(__u64))
252 		return -ERANGE;
253 
254 	/* return dos attributes as pseudo xattr */
255 	pcreatetime = (__u64 *)value;
256 	*pcreatetime = CIFS_I(inode)->createtime;
257 	return sizeof(__u64);
258 }
259 
260 
261 static int cifs_xattr_get(const struct xattr_handler *handler,
262 			  struct dentry *dentry, struct inode *inode,
263 			  const char *name, void *value, size_t size)
264 {
265 	ssize_t rc = -EOPNOTSUPP;
266 	unsigned int xid;
267 	struct super_block *sb = dentry->d_sb;
268 	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
269 	struct tcon_link *tlink;
270 	struct cifs_tcon *pTcon;
271 	const char *full_path;
272 	void *page;
273 
274 	tlink = cifs_sb_tlink(cifs_sb);
275 	if (IS_ERR(tlink))
276 		return PTR_ERR(tlink);
277 	pTcon = tlink_tcon(tlink);
278 
279 	xid = get_xid();
280 	page = alloc_dentry_path();
281 
282 	full_path = build_path_from_dentry(dentry, page);
283 	if (IS_ERR(full_path)) {
284 		rc = PTR_ERR(full_path);
285 		goto out;
286 	}
287 
288 	/* return alt name if available as pseudo attr */
289 	switch (handler->flags) {
290 	case XATTR_USER:
291 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
292 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
293 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
294 			rc = cifs_attrib_get(dentry, inode, value, size);
295 			break;
296 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
297 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
298 			rc = cifs_creation_time_get(dentry, inode, value, size);
299 			break;
300 		}
301 
302 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
303 			goto out;
304 
305 		if (pTcon->ses->server->ops->query_all_EAs)
306 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
307 				full_path, name, value, size, cifs_sb);
308 		break;
309 
310 	case XATTR_CIFS_ACL:
311 	case XATTR_CIFS_NTSD:
312 	case XATTR_CIFS_NTSD_FULL: {
313 		/*
314 		 * fetch owner, DACL, and SACL if asked for full descriptor,
315 		 * fetch owner and DACL otherwise
316 		 */
317 		u32 acllen, extra_info;
318 		struct cifs_ntsd *pacl;
319 
320 		if (pTcon->ses->server->ops->get_acl == NULL)
321 			goto out; /* rc already EOPNOTSUPP */
322 
323 		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
324 			extra_info = SACL_SECINFO;
325 		} else {
326 			extra_info = 0;
327 		}
328 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
329 				inode, full_path, &acllen, extra_info);
330 		if (IS_ERR(pacl)) {
331 			rc = PTR_ERR(pacl);
332 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
333 				 __func__, rc);
334 		} else {
335 			if (value) {
336 				if (acllen > size)
337 					acllen = -ERANGE;
338 				else
339 					memcpy(value, pacl, acllen);
340 			}
341 			rc = acllen;
342 			kfree(pacl);
343 		}
344 		break;
345 	}
346 	}
347 
348 	/* We could add an additional check for streams ie
349 	    if proc/fs/cifs/streamstoxattr is set then
350 		search server for EAs or streams to
351 		returns as xattrs */
352 
353 	if (rc == -EINVAL)
354 		rc = -EOPNOTSUPP;
355 
356 out:
357 	free_dentry_path(page);
358 	free_xid(xid);
359 	cifs_put_tlink(tlink);
360 	return rc;
361 }
362 
363 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
364 {
365 	ssize_t rc = -EOPNOTSUPP;
366 	unsigned int xid;
367 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
368 	struct tcon_link *tlink;
369 	struct cifs_tcon *pTcon;
370 	const char *full_path;
371 	void *page;
372 
373 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
374 		return -EIO;
375 
376 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
377 		return -EOPNOTSUPP;
378 
379 	tlink = cifs_sb_tlink(cifs_sb);
380 	if (IS_ERR(tlink))
381 		return PTR_ERR(tlink);
382 	pTcon = tlink_tcon(tlink);
383 
384 	xid = get_xid();
385 	page = alloc_dentry_path();
386 
387 	full_path = build_path_from_dentry(direntry, page);
388 	if (IS_ERR(full_path)) {
389 		rc = PTR_ERR(full_path);
390 		goto list_ea_exit;
391 	}
392 	/* return dos attributes as pseudo xattr */
393 	/* return alt name if available as pseudo attr */
394 
395 	/* if proc/fs/cifs/streamstoxattr is set then
396 		search server for EAs or streams to
397 		returns as xattrs */
398 
399 	if (pTcon->ses->server->ops->query_all_EAs)
400 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
401 				full_path, NULL, data, buf_size, cifs_sb);
402 list_ea_exit:
403 	free_dentry_path(page);
404 	free_xid(xid);
405 	cifs_put_tlink(tlink);
406 	return rc;
407 }
408 
409 static const struct xattr_handler cifs_user_xattr_handler = {
410 	.prefix = XATTR_USER_PREFIX,
411 	.flags = XATTR_USER,
412 	.get = cifs_xattr_get,
413 	.set = cifs_xattr_set,
414 };
415 
416 /* os2.* attributes are treated like user.* attributes */
417 static const struct xattr_handler cifs_os2_xattr_handler = {
418 	.prefix = XATTR_OS2_PREFIX,
419 	.flags = XATTR_USER,
420 	.get = cifs_xattr_get,
421 	.set = cifs_xattr_set,
422 };
423 
424 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
425 	.name = CIFS_XATTR_CIFS_ACL,
426 	.flags = XATTR_CIFS_ACL,
427 	.get = cifs_xattr_get,
428 	.set = cifs_xattr_set,
429 };
430 
431 /*
432  * Although this is just an alias for the above, need to move away from
433  * confusing users and using the 20 year old term 'cifs' when it is no
434  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
435  * SMB3 and later are highly secure.
436  */
437 static const struct xattr_handler smb3_acl_xattr_handler = {
438 	.name = SMB3_XATTR_CIFS_ACL,
439 	.flags = XATTR_CIFS_ACL,
440 	.get = cifs_xattr_get,
441 	.set = cifs_xattr_set,
442 };
443 
444 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
445 	.name = CIFS_XATTR_CIFS_NTSD,
446 	.flags = XATTR_CIFS_NTSD,
447 	.get = cifs_xattr_get,
448 	.set = cifs_xattr_set,
449 };
450 
451 /*
452  * Although this is just an alias for the above, need to move away from
453  * confusing users and using the 20 year old term 'cifs' when it is no
454  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
455  * SMB3 and later are highly secure.
456  */
457 static const struct xattr_handler smb3_ntsd_xattr_handler = {
458 	.name = SMB3_XATTR_CIFS_NTSD,
459 	.flags = XATTR_CIFS_NTSD,
460 	.get = cifs_xattr_get,
461 	.set = cifs_xattr_set,
462 };
463 
464 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
465 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
466 	.flags = XATTR_CIFS_NTSD_FULL,
467 	.get = cifs_xattr_get,
468 	.set = cifs_xattr_set,
469 };
470 
471 /*
472  * Although this is just an alias for the above, need to move away from
473  * confusing users and using the 20 year old term 'cifs' when it is no
474  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
475  * SMB3 and later are highly secure.
476  */
477 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
478 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
479 	.flags = XATTR_CIFS_NTSD_FULL,
480 	.get = cifs_xattr_get,
481 	.set = cifs_xattr_set,
482 };
483 
484 const struct xattr_handler *cifs_xattr_handlers[] = {
485 	&cifs_user_xattr_handler,
486 	&cifs_os2_xattr_handler,
487 	&cifs_cifs_acl_xattr_handler,
488 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
489 	&cifs_cifs_ntsd_xattr_handler,
490 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
491 	&cifs_cifs_ntsd_full_xattr_handler,
492 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
493 	NULL
494 };
495