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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 
cifs_attrib_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)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 
cifs_creation_time_set(unsigned int xid,struct cifs_tcon * pTcon,struct inode * inode,const char * full_path,const void * value,size_t size)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 
cifs_xattr_set(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * dentry,struct inode * inode,const char * name,const void * value,size_t size,int flags)91 static int cifs_xattr_set(const struct xattr_handler *handler,
92 			  struct user_namespace *mnt_userns,
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 	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 	free_dentry_path(page);
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)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)
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 	const char *full_path;
296 	void *page;
297 
298 	tlink = cifs_sb_tlink(cifs_sb);
299 	if (IS_ERR(tlink))
300 		return PTR_ERR(tlink);
301 	pTcon = tlink_tcon(tlink);
302 
303 	xid = get_xid();
304 	page = alloc_dentry_path();
305 
306 	full_path = build_path_from_dentry(dentry, page);
307 	if (IS_ERR(full_path)) {
308 		rc = PTR_ERR(full_path);
309 		goto out;
310 	}
311 
312 	/* return alt name if available as pseudo attr */
313 	switch (handler->flags) {
314 	case XATTR_USER:
315 		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
316 		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
317 		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
318 			rc = cifs_attrib_get(dentry, inode, value, size);
319 			break;
320 		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
321 		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
322 			rc = cifs_creation_time_get(dentry, inode, value, size);
323 			break;
324 		}
325 
326 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
327 			goto out;
328 
329 		if (pTcon->ses->server->ops->query_all_EAs)
330 			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
331 				full_path, name, value, size, cifs_sb);
332 		break;
333 
334 	case XATTR_CIFS_ACL:
335 	case XATTR_CIFS_NTSD:
336 	case XATTR_CIFS_NTSD_FULL: {
337 		/*
338 		 * fetch owner, DACL, and SACL if asked for full descriptor,
339 		 * fetch owner and DACL otherwise
340 		 */
341 		u32 acllen, extra_info;
342 		struct cifs_ntsd *pacl;
343 
344 		if (pTcon->ses->server->ops->get_acl == NULL)
345 			goto out; /* rc already EOPNOTSUPP */
346 
347 		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
348 			extra_info = SACL_SECINFO;
349 		} else {
350 			extra_info = 0;
351 		}
352 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
353 				inode, full_path, &acllen, extra_info);
354 		if (IS_ERR(pacl)) {
355 			rc = PTR_ERR(pacl);
356 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
357 				 __func__, rc);
358 		} else {
359 			if (value) {
360 				if (acllen > size)
361 					acllen = -ERANGE;
362 				else
363 					memcpy(value, pacl, acllen);
364 			}
365 			rc = acllen;
366 			kfree(pacl);
367 		}
368 		break;
369 	}
370 
371 	case XATTR_ACL_ACCESS:
372 #ifdef CONFIG_CIFS_POSIX
373 		if (sb->s_flags & SB_POSIXACL)
374 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
375 				value, size, ACL_TYPE_ACCESS,
376 				cifs_sb->local_nls,
377 				cifs_remap(cifs_sb));
378 #endif  /* CONFIG_CIFS_POSIX */
379 		break;
380 
381 	case XATTR_ACL_DEFAULT:
382 #ifdef CONFIG_CIFS_POSIX
383 		if (sb->s_flags & SB_POSIXACL)
384 			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,
385 				value, size, ACL_TYPE_DEFAULT,
386 				cifs_sb->local_nls,
387 				cifs_remap(cifs_sb));
388 #endif  /* CONFIG_CIFS_POSIX */
389 		break;
390 	}
391 
392 	/* We could add an additional check for streams ie
393 	    if proc/fs/cifs/streamstoxattr is set then
394 		search server for EAs or streams to
395 		returns as xattrs */
396 
397 	if (rc == -EINVAL)
398 		rc = -EOPNOTSUPP;
399 
400 out:
401 	free_dentry_path(page);
402 	free_xid(xid);
403 	cifs_put_tlink(tlink);
404 	return rc;
405 }
406 
cifs_listxattr(struct dentry * direntry,char * data,size_t buf_size)407 ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
408 {
409 	ssize_t rc = -EOPNOTSUPP;
410 	unsigned int xid;
411 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
412 	struct tcon_link *tlink;
413 	struct cifs_tcon *pTcon;
414 	const char *full_path;
415 	void *page;
416 
417 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
418 		return -EIO;
419 
420 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
421 		return -EOPNOTSUPP;
422 
423 	tlink = cifs_sb_tlink(cifs_sb);
424 	if (IS_ERR(tlink))
425 		return PTR_ERR(tlink);
426 	pTcon = tlink_tcon(tlink);
427 
428 	xid = get_xid();
429 	page = alloc_dentry_path();
430 
431 	full_path = build_path_from_dentry(direntry, page);
432 	if (IS_ERR(full_path)) {
433 		rc = PTR_ERR(full_path);
434 		goto list_ea_exit;
435 	}
436 	/* return dos attributes as pseudo xattr */
437 	/* return alt name if available as pseudo attr */
438 
439 	/* if proc/fs/cifs/streamstoxattr is set then
440 		search server for EAs or streams to
441 		returns as xattrs */
442 
443 	if (pTcon->ses->server->ops->query_all_EAs)
444 		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
445 				full_path, NULL, data, buf_size, cifs_sb);
446 list_ea_exit:
447 	free_dentry_path(page);
448 	free_xid(xid);
449 	cifs_put_tlink(tlink);
450 	return rc;
451 }
452 
453 static const struct xattr_handler cifs_user_xattr_handler = {
454 	.prefix = XATTR_USER_PREFIX,
455 	.flags = XATTR_USER,
456 	.get = cifs_xattr_get,
457 	.set = cifs_xattr_set,
458 };
459 
460 /* os2.* attributes are treated like user.* attributes */
461 static const struct xattr_handler cifs_os2_xattr_handler = {
462 	.prefix = XATTR_OS2_PREFIX,
463 	.flags = XATTR_USER,
464 	.get = cifs_xattr_get,
465 	.set = cifs_xattr_set,
466 };
467 
468 static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
469 	.name = CIFS_XATTR_CIFS_ACL,
470 	.flags = XATTR_CIFS_ACL,
471 	.get = cifs_xattr_get,
472 	.set = cifs_xattr_set,
473 };
474 
475 /*
476  * Although this is just an alias for the above, need to move away from
477  * confusing users and using the 20 year old term 'cifs' when it is no
478  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
479  * SMB3 and later are highly secure.
480  */
481 static const struct xattr_handler smb3_acl_xattr_handler = {
482 	.name = SMB3_XATTR_CIFS_ACL,
483 	.flags = XATTR_CIFS_ACL,
484 	.get = cifs_xattr_get,
485 	.set = cifs_xattr_set,
486 };
487 
488 static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
489 	.name = CIFS_XATTR_CIFS_NTSD,
490 	.flags = XATTR_CIFS_NTSD,
491 	.get = cifs_xattr_get,
492 	.set = cifs_xattr_set,
493 };
494 
495 /*
496  * Although this is just an alias for the above, need to move away from
497  * confusing users and using the 20 year old term 'cifs' when it is no
498  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
499  * SMB3 and later are highly secure.
500  */
501 static const struct xattr_handler smb3_ntsd_xattr_handler = {
502 	.name = SMB3_XATTR_CIFS_NTSD,
503 	.flags = XATTR_CIFS_NTSD,
504 	.get = cifs_xattr_get,
505 	.set = cifs_xattr_set,
506 };
507 
508 static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
509 	.name = CIFS_XATTR_CIFS_NTSD_FULL,
510 	.flags = XATTR_CIFS_NTSD_FULL,
511 	.get = cifs_xattr_get,
512 	.set = cifs_xattr_set,
513 };
514 
515 /*
516  * Although this is just an alias for the above, need to move away from
517  * confusing users and using the 20 year old term 'cifs' when it is no
518  * longer secure and was replaced by SMB2/SMB3 a long time ago, and
519  * SMB3 and later are highly secure.
520  */
521 static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
522 	.name = SMB3_XATTR_CIFS_NTSD_FULL,
523 	.flags = XATTR_CIFS_NTSD_FULL,
524 	.get = cifs_xattr_get,
525 	.set = cifs_xattr_set,
526 };
527 
528 
529 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
530 	.name = XATTR_NAME_POSIX_ACL_ACCESS,
531 	.flags = XATTR_ACL_ACCESS,
532 	.get = cifs_xattr_get,
533 	.set = cifs_xattr_set,
534 };
535 
536 static const struct xattr_handler cifs_posix_acl_default_xattr_handler = {
537 	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
538 	.flags = XATTR_ACL_DEFAULT,
539 	.get = cifs_xattr_get,
540 	.set = cifs_xattr_set,
541 };
542 
543 const struct xattr_handler *cifs_xattr_handlers[] = {
544 	&cifs_user_xattr_handler,
545 	&cifs_os2_xattr_handler,
546 	&cifs_cifs_acl_xattr_handler,
547 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
548 	&cifs_cifs_ntsd_xattr_handler,
549 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
550 	&cifs_cifs_ntsd_full_xattr_handler,
551 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
552 	&cifs_posix_acl_access_xattr_handler,
553 	&cifs_posix_acl_default_xattr_handler,
554 	NULL
555 };
556